Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2015	Feb. 29, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	Arbutus Biopharma Corp
Document Type	10-K
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		54,625,703
Entity Public Float			$ 644,038,348
Amendment Flag	false
Entity Central Index Key	0001447028
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 166,779	$ 72,187
Short-term investments	14,525	39,974
Accounts receivable	1,008	1,903
Accrued revenue	128	538
Investment tax credits receivable	246	86
Prepaid expenses and other assets	1,196	1,730
Total current assets	183,882	116,418
Property and equipment	12,912	12,959
Less accumulated depreciation	(9,729)	(11,199)
Property and equipment, net of accumulated depreciation	3,183	1,760
Long-term investments	10,070	0
Intangible assets	352,642	0
Goodwill	162,514	0
Total assets	712,291	118,178
Current liabilities:
Accounts payable and accrued liabilities	8,827	9,328
Deferred revenue	868	5,779
Warrants	883	5,099
Total current liabilities	10,578	20,206
Deferred revenue, net of current portion	213	9,937
Contingent consideration	7,497	0
Deferred tax liability	146,324	0
Total liabilities	164,612	30,143
Stockholders’ equity:
Common shares, authorized - unlimited number with no par value, Issued and outstanding: 54,570,691 (December 31, 2014 - 22,438,169)	834,240	290,004
Additional paid-in capital	30,206	26,208
Deficit	(266,985)	(205,864)
Accumulated other comprehensive loss	(49,782)	(22,313)
Total stockholders' equity	547,679	88,035
Total liabilities and stockholders' equity	$ 712,291	$ 118,178

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common shares, par value (in USD per share)	$ 0	$ 0
Common shares, shares issued	54,570,691	22,438,169
Common shares, shares outstanding	54,570,691	22,438,169

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue
Collaborations and contracts	$ 13,309	$ 11,738	$ 10,425
Licensing fees, milestone and royalty payments	11,564	3,215	5,040
Total revenue	24,873	14,953	15,465
Expenses
Research, development, collaborations and contracts	51,505	38,713	21,458
General and administrative	26,438	8,683	5,546
Depreciation of property and equipment	589	529	613
Acquisition costs	9,656	462	0
Impairment of intangible assets	39,007	0	0
Total expenses	127,195	48,387	27,617
Loss from operations	(102,322)	(33,434)	(12,152)
Other income (losses)
Interest income	674	853	540
Foreign exchange gains	21,771	4,127	1,079
Decrease (increase) in fair value of warrant liability	3,341	(10,383)	(3,530)
Increase in fair value of contingent consideration	(770)	0	0
Total other income (losses)	25,016	(5,403)	(1,911)
Loss before income taxes	(77,306)	(38,837)	(14,063)
Deferred income tax recovery	16,185	0	0
Net loss	$ (61,121)	$ (38,837)	$ (14,063)
Loss per common share
Basic loss per common share (in USD per share)	$ (1.34)	$ (1.80)	$ (0.92)
Diluted loss per common share (in USD per share)	$ (1.34)	$ (1.80)	$ (0.92)
Weighted average number of common shares
Basic weighted average number of common shares (in shares)	45,462,324	21,603,136	15,302,680
Diluted weighted average number of common shares (in shares)	45,462,324	21,603,136	15,302,680
Other Comprehensive loss
Cumulative translation adjustment	$ (27,469)	$ (6,489)	$ (3,135)
Comprehensive loss	$ (88,590)	$ (45,326)	$ (17,198)

Consolidated Statement of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Deficit	Accumulated other comprehensive loss
Balance (in shares) at Dec. 31, 2012		14,305,356
Balance at Dec. 31, 2012	$ 40,919	$ 181,786	$ 24,786	$ (152,964)	$ (12,689)
Stock-based compensation	903		903
Issuance of common shares pursuant to exercise of options (in shares)		125,596
Issuance of common shares pursuant to exercise of options	389	$ 735	(346)
Issuance of common shares pursuant to exercise of warrants (in shares)		305,448
Issuance of common shares pursuant to exercise of warrants	2,143	$ 2,143
Issuance of common shares in conjunction with the private (public in 2015) offering, net of issuance costs (in shares)		4,312,500
Issuance of common shares in conjunction with the private (public in 2015) offering, net of issuance costs	32,038	$ 32,038
Currency translation adjustment	(3,135)				(3,135)
Net loss	(14,063)			(14,063)
Balance (in shares) at Dec. 31, 2013		19,048,900
Balance at Dec. 31, 2013	59,194	$ 216,702	25,343	(167,027)	(15,824)
Stock-based compensation	3,283		3,283
Issuance of common shares pursuant to exercise of options (in shares)		648,506
Issuance of common shares pursuant to exercise of options	2,616	$ 5,034	(2,418)
Issuance of common shares pursuant to exercise of warrants (in shares)		615,763
Issuance of common shares pursuant to exercise of warrants	11,791	$ 11,791
Issuance of common shares in conjunction with the private (public in 2015) offering, net of issuance costs (in shares)		2,125,000
Issuance of common shares in conjunction with the private (public in 2015) offering, net of issuance costs	56,477	$ 56,477
Currency translation adjustment	(6,489)				(6,489)
Net loss	(38,837)			(38,837)
Balance (in shares) at Dec. 31, 2014		22,438,169
Balance at Dec. 31, 2014	88,035	$ 290,004	26,208	(205,864)	(22,313)
Stock-based compensation	22,093	$ 16,687	5,406
Issuance of common shares pursuant to exercise of options (in shares)		640,457
Issuance of common shares pursuant to exercise of options	1,651	$ 4,186	(2,535)
Issuance of common shares pursuant to exercise of warrants (in shares)		18,750
Issuance of common shares pursuant to exercise of warrants	371	$ 371
Issuance of common shares in conjunction with the private (public in 2015) offering, net of issuance costs (in shares)		7,500,000
Issuance of common shares in conjunction with the private (public in 2015) offering, net of issuance costs	142,177	$ 142,177
Increase of equity instruments in conjunction with the acquisition of Arbutus Inc. (in shares)		23,973,315
Increase of equity instruments in conjunction with the acquisition of Arbutus Inc.	381,942	$ 380,815	1,127
Currency translation adjustment	(27,469)				(27,469)
Net loss	(61,121)			(61,121)
Balance (in shares) at Dec. 31, 2015		54,570,691
Balance at Dec. 31, 2015	$ 547,679	$ 834,240	$ 30,206	$ (266,985)	$ (49,782)

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING ACTIVITIES
Net loss for the period	$ (61,121,000)	$ (38,837,000)	$ (14,063,000)
Items not involving cash:
Deferred income taxes	(16,185,000)	0	0
Depreciation of property and equipment	589,000	529,000	613,000
Gain on sale of property and equipment	0	(80,000)	0
Unrealized foreign exchange (gains) losses	(21,966,000)	(4,218,000)	(18,000)
Change in fair value of warrant liability	(3,341,000)	10,383,000	3,530,000
Change in fair value of contingent consideration	770,000	0	0
Impairment of intangible assets	39,007,000	0	0
Net change in non-cash operating items:
Accounts receivable	628,000	(1,887,000)	889,000
Accrued revenue	349,000	(360,000)	2,008,000
Deferred expenses	0	167,000	231,000
Investment tax credits receivable	(188,000)	(52,000)	(31,000)
Prepaid expenses and other assets	159,000	(773,000)	(776,000)
Accounts payable and accrued liabilities	(2,489,000)	6,253,000	130,000
Deferred revenue	(13,090,000)	13,171,000	(153,000)
Net cash used in operating activities	(54,785,000)	(12,421,000)	(6,737,000)
INVESTING ACTIVITIES
Disposition (acquisition) of investments	9,645,000	(41,982,000)	0
Cash acquired through acquisition	324,000	0	0
Proceeds from sale of property and equipment	0	80,000	0
Acquisition of property and equipment	(2,287,000)	(1,056,000)	(725,000)
Net cash provided by (used in) investing activities	7,682,000	(42,958,000)	(725,000)
FINANCING ACTIVITIES
Proceeds from issuance of common shares, net of issuance costs	142,177,000	56,477,000	32,038,000
Issuance of common shares pursuant to exercise of options	1,651,000	2,616,000	389,000
Issuance of common shares pursuant to exercise of warrants	42,000	1,583,000	289,000
Net cash provided by financing activities	143,870,000	60,676,000	32,716,000
Effect of foreign currency rate changes on cash and cash equivalents	(2,175,000)	(1,827,000)	(3,561,000)
Increase in cash and cash equivalents	94,592,000	3,470,000	21,693,000
Cash and cash equivalents, beginning of period	72,187,000	68,717,000	47,024,000
Cash and cash equivalents, end of period	166,779,000	72,187,000	68,717,000
Supplemental cash flow information
Fair value of warrants exercised on a cashless basis	0	(116,000)	1,404,000
Investment tax credits received	24,000	0	10,000
Acquisition of Arbutus Inc. net of cash acquired	381,618,000	0	0
Research, development, collaborations
Items not involving cash:
Stock-based compensation	7,869,000	2,343,000	622,000
General and administrative expenses
Items not involving cash:
Stock-based compensation	$ 14,224,000	$ 940,000	$ 281,000

Nature of Business and Future Operations	12 Months Ended
Nature of Business and Future Operations	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of business and future operations	Nature of business and future operations Arbutus Biopharma Corporation (the “Company” or “Arbutus”) is a Canadian biopharmaceutical business dedicated to discovering, developing, and commercializing a cure for patients suffering from chronic hepatitis B infection (HBV), a disease of the liver caused by the hepatitis B virus (“HBV”). The Company is also developing a pipeline focused on advancing novel RNA interference therapeutics (RNAi) leveraging the Company’s expertise in Lipid Nanoparticle (LNP) technology. Effective July 31, 2015, the corporate name changed from Tekmira Pharmaceuticals Corporation (Tekmira) to Arbutus Biopharma Corporation. Also effective July 31, 2015, the corporate name of the wholly-owned subsidiary, OnCore Biopharma, Inc. (OnCore) changed to Arbutus Biopharma, Inc. (Arbutus Inc.). Including Arbutus Inc., the Company has four wholly-owned subsidiaries: Protiva Biotherapeutics Inc. (Protiva), Protiva Biotherapeutics (USA) Inc. (Protiva USA), and Protiva Agricultural Development Company Inc. (“PADCo”). In March 2016, Monsanto exercised its option to acquire 100% of the outstanding shares in PADCo - refer to note 13 subsequent events. The success of the Company is dependent on obtaining the necessary regulatory approvals to bring its products to market and achieve profitable operations. The continuation of the research and development activities and the commercialization of its products are dependent on the Company’s ability to successfully complete these activities and to obtain adequate financing through a combination of financing activities and operations. It is not possible to predict either the outcome of future research and development programs or the Company’s ability to continue to fund these programs in the future.

Significant Accounting Policies

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Significant accounting policies

Basis of presentation

Arbutus Biopharma Corporation (formerly Tekmira Pharmaceuticals Corporation) was incorporated on October 6, 2005 as an inactive wholly owned subsidiary of Inex Pharmaceuticals Corporation (Inex). Pursuant to a “Plan of Arrangement” effective April 30, 2007, the business and substantially all of the assets and liabilities of Inex were transferred to the Company. The consolidated financial statements for all periods presented herein include the consolidated operations of Inex until April 30, 2007 and the operations of the Company thereafter.

The Company has four wholly-owned subsidiaries as at December 31, 2015: Arbutus Biopharma, Inc. (formerly OnCore Biopharma, Inc.) Protiva Biotherapeutics Inc. (Protiva), Protiva Biotherapeutics (USA) Inc. (Protiva USA), and Protiva Agricultural Development Company Inc. (“PADCo”). Protiva and Protiva USA were acquired on May 30, 2008. PADCo was incorporated on January 9, 2014. Arbutus Inc. was acquired by way of a Merger Agreement on March 4, 2015, which included Arbutus Inc.'s wholly-owned subsidiary, Enantigen Therapeutics, Inc. (Enantigen) - see note 3. Enantigen was merged with Arbutus Inc. on September 30, 2015.

These consolidated financial statements include the accounts of the Company and three of its wholly-owned subsidiaries, Arbutus Inc., Protiva and Protiva USA. All intercompany transactions and balances have been eliminated on consolidation.

The Company records its investment in PADCo using the equity method. The Company has determined that PADCo is a variable interest entity (“VIE”) of which it is not the primary beneficiary. The Company is not the primary beneficiary as it does not have the power to make decisions that most significantly affect the economic performance of the VIE nor does the Company have the right to receive benefits or the obligation to absorb losses that in either case could potentially be significant to the VIE. PADCo is described further in note 4(b). In March 2016, Monsanto exercised its option to acquire PADCo - refer to note 13 subsequent events.

Use of estimates

The preparation of the consolidated financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions about future events that affect the reported amounts of assets, liabilities, revenue, expenses, contingent assets and contingent liabilities as at the end or during the reporting period. Actual results could significantly differ from those estimates. Significant areas requiring the use of management estimates relate to purchase price allocation, valuation of intangible assets and goodwill, recognition of revenue, stock-based compensation, valuation of warrant liability and financial instrument, and the amounts recorded as accrued liabilities, contingent consideration, and income tax recovery.

Cash and cash equivalents

Cash and cash equivalents are all highly liquid instruments with an original maturity of three months or less when purchased. Cash equivalents are recorded at cost plus accrued interest. The carrying value of these cash equivalents approximates their fair value.

Short-term and long-term investments

The Company acquired guaranteed investment certificates and a term deposit during the year, which are classified as short-term and long-term investments on the balance sheet respectively. Short-term investments have original maturities exceeding three months, and have remaining maturities less than one year. Long-term investments have remaining maturities exceeding twelve months. Short-term and long-term investments accrue interest daily based on a fixed interest rate for the term. The carrying value of these investments are recorded at cost plus accrued interest, which approximates their fair value. All investments are governed by the Board approved Investment Policy for the Company.

Fair value of financial instruments

We measure certain financial instruments and other items at fair value.

To determine the fair value, we use the fair value hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use to value an asset or liability and are developed based on market data obtained from independent sources. Unobservable inputs are inputs based on assumptions about the factors market participants would use to value an asset or liability. The three levels of inputs that may be used to measure fair value are as follows:


•	Level 1 inputs are quoted market prices for identical instruments available in active markets.


•	Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets.


•	Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability.

Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy.

The Company’s financial instruments consist of cash and cash equivalents, short-term and long-term investments, accounts receivable, accounts payable and accrued liabilities, warrants and financial instruments. Long-term investments approximate fair value due to the interest rates being at prevailing market rates.

The carrying values of cash and cash equivalents, short-term investments, accounts receivable and accounts payable and accrued liabilities approximate their fair values due to the immediate or short-term maturity of these financial instruments.

As quoted prices for the warrants are not readily available, the Company has used a Black-Scholes pricing model, as described in note 6, to estimate fair value. These are level 3 inputs as defined above.

The Company used a discounted cash flow model to determine the fair value of the financial instrument related to Monsanto’s call option to acquire the equity or all of the assets of PADCo, as described in note 4. The fair value was determined at the date of recognition, and at each reporting date. The initial fair value of the financial instrument was nil, and there has been no change to its fair value as at December 31, 2015. The assumptions used in the discounted cash flow model are level 3 inputs as defined above.

To determine the fair value of the contingent consideration, the Company uses a probability weighted assessment of the likelihood the milestones would be met and the estimated timing of such payments, and then the potential contingent payments were discounted to their present value using a probability adjusted discount rate that reflects the early stage nature of the development program, time to complete the program development, and overall biotech indices, as in note 9. The fair value was determine at the date of recognition to be $6,727,000. The Company determined the fair value of the contingent consideration has increased by $770,000 to $7,497,000 and the increase in fair value has been recorded in other losses in the statement of operations and comprehensive loss for the year-ended December 31, 2015. The assumptions used in the discounted cash flow model are level 3 inputs as defined above.

The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques used to determine such fair value:



	Level 1		Level 2	Level 3		December 31, 2015
Assets
Cash and cash equivalents	$	166,779	—	—		$	166,779
Guaranteed investment certificate	14,525		—	—		14,525
Term deposit	10,070		—	—		10,070
Total	$	191,374	—	—		$	191,374
Liabilities
Warrants	—		—	$	883	$	883
Contingent consideration	—		—	7,497		7,497
Financial instrument	—		—	—		—
Total	—		—	$	8,380	$	8,380



	Level 1		Level 2	Level 3		December 31, 2014
Assets
Cash and cash equivalents	$	72,187	—	—		$	72,187
Guaranteed investment certificates	39,974		—	—		39,974
Total	$	112,161	—	—		$	112,161
Liabilities
Warrants	—		—	$	5,099	$	5,099
Financial instrument	—		—	—		—
Total	—		—	$	5,099	$	5,099

The following table presents the changes in fair value of the Company’s warrants:



	Liability at beginning of the period		Warrants issued in the period		Fair value of warrants exercised in the period			Increase (decrease) in fair value of warrants			Foreign exchange loss			Liability at end of the period
Year ended December 31, 2013	$	4,015	$	—	$	(1,854	)	$	3,530		$	(312	)	$	5,379
Year ended December 31, 2014	$	5,379	—		$	(10,208	)	$	10,383		$	(455	)	$	5,099
Year ended December 31, 2015	$	5,099	—		$	(334	)	$	(3,341	)	$	(541	)	$	883

The following table presents the changes in fair value of the Company’s contingent consideration:



	Liability at beginning of the period ⁽¹⁾		Increase in fair value of contingent consideration		Liability at end of the period
Year ended December 31, 2015	$	6,727	$	770	$	7,497

(1) As at acquisition date of March 4, 2015 - see note 3 below.

Inventory

Inventory includes materials assigned for the manufacture of products for collaborative partners and manufacturing costs for products awaiting acceptance by collaborative partners. Inventory is carried at the lower of cost and net realizable value and measured using first-in-first-out method. The cost of inventories includes all costs of purchase, costs of manufacturing and other costs incurred in bringing the inventories to their present location and condition.

Materials purchased for the Company’s own research and development products are not recorded as inventory but are expensed as incurred.

Property and equipment

Property and equipment is recorded at cost less impairment losses, accumulated depreciation, related government grants and investment tax credits. The Company records depreciation using the straight-line method over the estimated useful lives of the capital assets as follows:



	Useful life (years)
Laboratory equipment		5
Computer and office equipment	2	—	5
Furniture and fixtures		5

Leasehold improvements are depreciated over their estimated useful lives but in no case longer than the lease term, except where lease renewal is reasonably assured.

If there is a major event indicating that the carrying value of property and equipment may be impaired then management will perform an impairment test and if the carrying value exceeds the recoverable value, based on undiscounted future cash flows, then such assets are written down to their fair values.

Goodwill and intangible assets

The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.

Intangible assets consist of in-process research and development arising from the Company’s acquisition of Arbutus Inc. - see note 3. In-process research and development (IPR&D) intangible assets are classified as indefinite-lived and are not amortized. IPR&D becomes definite-lived upon the completion or abandonment of the associated research and development efforts. Intangible assets with finite useful lives are amortized on a straight-line basis over their estimated useful lives, which are the respective patent terms. Amortization begins when intangible assets with finite lives are put into use. If there is a major event indicating that the carrying value of intangible assets may be impaired, then management will perform an impairment test and if the carrying value exceeds the recoverable value, based on discounted future cash flows, then such assets are written down to their fair values.

Goodwill represents the excess of purchase price over the value assigned to the net tangible and identifiable intangible assets of Arbutus Inc. - see note 3. Goodwill has an indefinite accounting life and is therefore not amortized. Instead, goodwill is subject to a two-step impairment test on an annual basis, unless the Company identifies impairment indicators that would require earlier testing. The first step compares the fair value of the reporting unit to its carrying amount, which includes the goodwill. When the fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is considered not to be impaired, and the second step of the impairment test is unnecessary. If the carrying amount exceeds the implied fair value of the reporting unit, the second step measures the amount of the impairment loss. If the carrying amount exceeds the fair value of the reporting unit, an impairment loss is recognized equal to that excess.

The Company reviews the recoverable amount of intangible assets on an annual basis, and the annual evaluation for goodwill is performed as of December 31 each year. In addition, the Company evaluates for events or changes in the business that could indicate impairment and earlier testing. Such indicators include, but are not limited to, on an ongoing basis: (a) industry and market considerations such as increased competitive environment or adverse change in legal factors including an adverse assessment by regulators; (b) an accumulation of costs significantly in excess of the amount originally expected for the development of the asset; (c) current period operating or cash flow loss combined with a history of operating or cash flow losses or a projection or forecast that demonstrates continuing losses associated with the use of the asset; and (d) if applicable, a sustained decrease in share price.

Revenue recognition

The Company earns revenue from research and development collaboration and contract services, licensing fees, milestone and royalty payments. Revenues associated with multiple element arrangements are attributed to the various elements based on their relative fair values or are recognized as a single unit of accounting when relative fair values are not determinable. Non-refundable payments received under collaborative research and development agreements are recorded as revenue as services are performed and related expenditures are incurred. Non-refundable upfront license fees from collaborative licensing and development arrangements are recognized as the Company fulfills its obligations related to the various elements within the agreements, in accordance with the contractual arrangements with third parties and the term over which the underlying benefit is being conferred. The Company evaluates new arrangements for any substantive milestones by considering: whether substantive uncertainty exists upon execution of the arrangement; if the event can only be achieved based in whole or in part on the Company’s performance, or occurrence of a specific outcome resulting from the Company’s performance; any future performance required, and payment is reasonable relative to all deliverables; and, the payment terms in the arrangement. Payments received upon the achievement of substantive milestones are recognized as revenue in their entirety. Payments received upon the occurrence of milestones that are non-substantive are deferred and recognized as revenue over the estimated period of performance applicable to the associated collaborative agreement.

Revenue earned under research and development manufacturing collaborations where the Company bears some or all of the risk of a product manufacturing failure is recognized when the purchaser accepts the product and there are no remaining rights of return.

Revenue earned under research and development collaborations where the Company does not bear any risk of product manufacturing failure is recognized in the period the work is performed. For contracts where the manufacturing amount is specified, revenue is recognized as product is manufactured in proportion to the total amount specified under the contract.

Revenue and expenses under the contract with the United States Government Department of Defense (“DoD”) are being recorded using the percentage-of-completion method. Contract progress is based on costs incurred to date. Expenses under the contract are recorded in the Company’s consolidated statement of operations and comprehensive income (loss) as they are incurred. Government contract revenues related to expenses incurred under the contract are recorded in the same period as those expenses. Expenses accrued under the contract but not yet invoiced are recorded in the Company’s balance sheet as accrued liabilities and accrued revenues. Equipment purchased under the contract is recorded on the Company’s balance sheet as deferred expense and deferred revenue and amortized, on a straight-line basis, over the life of the contract.

Cash or other compensation received in advance of meeting the revenue recognition criteria is recorded on the balance sheet as deferred revenue. Revenue meeting recognition criteria but not yet received or receivable is recorded on the balance sheet as accrued revenue.

Leases and lease inducements

Leases entered into are classified as either capital or operating leases. Leases which substantially transfer all benefits and risks of ownership of property to the Company are accounted for as capital leases. At the time a capital lease is entered into, an asset is recorded together with its related long-term obligation to reflect the purchase and financing.

All other leases are accounted for as operating leases wherein rental payments are expensed as incurred.

Lease inducements represent leasehold improvement allowances and reduced or free rent periods and are amortized on a straight-line basis over the term of the lease and are recorded as a reduction of rent expense.

Research and development costs

Research and development costs, including acquired in-process research and development expenses for which there is no alternative future use, are charged as an expense in the period in which they are incurred.

Income or loss per share

Income or loss per share is calculated based on the weighted average number of common shares outstanding. Diluted loss per share does not differ from basic loss per share for the years ended December 31, 2015, 2014 and 2013, since the effect of the Company’s stock options and warrants is anti-dilutive.

The following table sets out the computation of basic and diluted net income (loss) per common share:



	For the year ended December 31
	2015			2014			2013
Numerator:
Net loss	$	(61,121	)	$	(38,837	)	$	(14,063	)
Denominator:
Weighted average number of common shares	45,462,324			21,603,136			15,302,680
Basic income (loss) per common share	$	(1.34	)	$	(1.80	)	$	(0.92	)
Diluted income (loss) per common share	$	(1.34	)	$	(1.80	)	$	(0.92	)

For the year ended December 31, 2015, potential common shares of 2,899,331 were excluded from the calculation of income per common share because their inclusion would be anti-dilutive (December 31, 2014 – 2,221,233; December 31, 2013 – 3,064,767).

Government grants and refundable investment tax credits

Government grants and tax credits provided for current expenses is included in the determination of income or loss for the year, as a reduction of the expenses to which it relates. Government grants and tax credits towards the acquisition of property and equipment is deducted from the cost of the related property and equipment.

Foreign currency translation and change in reporting currency

The functional currency of the Company and two of its integrated subsidiaries (Protiva and Protiva USA), is the Canadian dollar, and the functional currency of Arbutus Inc. is the U.S. dollar. Foreign currency monetary assets and liabilities are translated into the functional currency at the rate of exchange prevailing at the balance sheet date. Non-monetary assets and liabilities are translated at historical exchange rates. The previous month’s average rate of exchange is used to translate revenue and expense transactions. Exchange gains and losses are included in income or loss for the period.

The Company is using United States dollars as its reporting currency. All assets and liabilities are translated using the exchange rate at the balance sheet date. Revenues, expenses and other income (losses) are translated using the average rate for the period, except for large transactions, for which the exchange rate on the date of the transaction is used. Equity accounts are translated using the historical rate. As the translation differences from the Company’s functional currency of Canadian dollars to the Company’s reporting currency of US dollars are unrealized gains and losses, the differences are recorded in other comprehensive income (loss), and do not impact the calculation of Income or Loss per Share.

On January 1, 2016, the Company changed its functional currency from the Canadian dollar to the U.S. dollar based on management's analysis of the changes in the primary economic environment in which the Company operates. The change in functional currency is accounted for prospectively from January 1, 2016 and financial statements prior to and including the year-ended December 31, 2015 have not been restated for the change in functional currency.

Deferred income taxes

Income taxes are accounted for using the asset and liability method of accounting. Deferred income taxes are recognized for the future income tax consequences attributable to differences between the carrying values of assets and liabilities and their respective income tax bases and for loss carry-forwards. Deferred income tax assets and liabilities are measured using enacted income tax rates expected to apply to taxable income in the periods in which temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax laws or rates is included in earnings in the period that includes the enactment date. When realization of deferred income tax assets does not meet the more-likely-than-not criterion for recognition, a valuation allowance is provided.

Stock-based compensation

The Company grants stock options to employees and directors pursuant to a share incentive plan described in note 6. Compensation expense is recorded for issued stock options using the fair value method with a corresponding increase in additional paid-in capital. Any consideration received on the exercise of stock options is credited to share capital.

The fair value of stock options is measured at the grant date and amortized on a straight-line basis over the vesting period.

Replacement awards

Replacement awards are share-based payment awards exchanged for awards held by employees of Arbutus Inc. As part of the Company’s acquisition of Arbutus Inc., Arbutus shares were exchanged for Arbutus Inc.’s shares subject to repurchase rights held by Arbutus Inc.’s employees - see note 3.

As at the date of acquisition of Arbutus Inc., the Company determined the total fair value of replacement awards and attributed a portion of the replacement awards to pre-combination service as part of the total acquisition consideration, and a portion to post-combination service, which is recognized as compensation expense over the expiry period of repurchase provision rights subsequent to the acquisition date.

The replacement awards consist of common shares that were issued at acquisition. Accordingly, as stock compensation expense related to these awards is recognized, share capital is increased by a corresponding amount. Replacement awards are excluded in the calculation of basic net income (loss) per share until the repurchase rights have expired.

Warrants

The Company accounts for the warrants under the authoritative guidance on accounting for derivative financial instruments indexed to, and potentially settled in, a company’s own stock, on the understanding that in compliance with applicable securities laws, the registered warrants require the issuance of registered securities upon exercise and do not sufficiently preclude an implied right to net cash settlement. The Company classifies warrants in its consolidated balance sheet as a liability which is revalued at each balance sheet date subsequent to the initial issuance. The Company uses the Black-Scholes pricing model to value the warrants. Determining the appropriate fair-value model and calculating the fair value of registered warrants requires considerable judgment. A small change in the estimates used may cause a relatively large change in the estimated valuation. The estimated volatility of the Company’s common stock at the date of issuance, and at each subsequent reporting period, is based on historic fluctuations in the Company’s stock price. The risk-free interest rate is based on the Government of Canada rate for bonds with a maturity similar to the expected remaining life of the warrants at the valuation date. The expected life of the warrants is based on the historical pattern of exercises of warrants.

Segment information

The Company operates in a single reporting segment. Substantially all of the Company’s revenues to date were earned from customers or collaborators based in the United States. Substantially all of the Company’s premises, property and equipment are located in Canada and the United States.

Recent accounting pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842): Recognition and Measurement of Financial Assets and Financial Liabilities. The update supersedes Topic 840, Leases and requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. Topic 842 retains a distinction between finance leases and operating leases, with cash payments from operating leases classified within operating activities in the statement of cash flows. The amendments in this update are effective for fiscal years beginning after December 15, 2018 for public business entities, which for the Company means January 1, 2019. The Company does not plan to early adopt this update. The extent of the impact of this adoption has not yet been determined.

In September 2015, the FASB issued ASU 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. The update eliminates the requirement to retrospectively adjust the provisional amounts recognized at the acquisition date with a corresponding adjustment to goodwill during the measurement period when new information is obtained about the facts and circumstances that existed as of the acquisition date, that if known, would have affected the measurement of the amounts initially recognized or would have resulted in the recognition of additional assets or liabilities. The amendments in this update are effective for fiscal years beginning after December 15, 2015, which for the Company means January 1, 2016, and should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this update. Early application is permitted for financial statements that have not been issued. The Company has adopted this update and applied it to the acquisition of Arbutus Inc.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (ASC 606). The standard is intended to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and IFRS by creating a new Topic 606, Revenue from Contracts with Customers. This guidance supersedes the revenue recognition requirements in ASC 605, Revenue Recognition, and supersedes some cost guidance included in Subtopic 605-35, Revenue Recognition - Construction-Type and Production-Type Contracts. The core principle of the accounting standard is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those good or services. The amendments should be applied by either (1) retrospectively to each prior reporting period presented; or (2) retrospectively with the cumulative effect of initially applying this ASU recognized at the date of initial application. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date to defer the effective date of Update 2014-09 for all entities by one year. The new guidance would be effective for fiscal years beginning after December 15, 2017, which for the Company means January 1, 2018. Entities are permitted to adopt in accordance with the original effective date if they choose. The Company has not yet determined the extent of the impact of adoption.

In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. The update is intended to provide guidance in GAAP about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. Under amendments to GAAP, the assessment period is within one year after the date that the financial statements are issued (or available to be issued). The amendments are effective for the annual period ending after December 15, 2016, which for the Company means January 1, 2017, and for annual periods and interim periods thereafter. Early application is permitted. The Company does not plan to early adopt this update. The extent of the impact of this adoption has not yet been determined.

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.)

12 Months Ended

Dec. 31, 2015

Business Combinations [Abstract]

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.)

Merger with Arbutus Biopharma, Inc. (formerly OnCore BioPharma, Inc.)

(a) Purchase Price Allocation

On January 11, 2015, the Company entered into a Merger Agreement to acquire 100% of the outstanding shares of Arbutus Inc. (formerly OnCore Biopharma, Inc.) and its wholly-owned subsidiary, Enantigen (see note 9). Arbutus Inc. was a privately owned U.S. company focused on discovery, development and commercialization of an all-oral cure regimen for patients with HBV. The merger was approved by the Company’s shareholders on March 3, 2015 and closed on March 4, 2015. Arbutus Inc.’s results of operations and fair value of assets acquired and liabilities assumed are included in the Company’s consolidated financial statements from the date of acquisition.

The transaction has been accounted for using the acquisition method based on ASC 805, Business Combinations, with Arbutus (formerly Tekmira) identified as the acquirer, based on managements’ analysis and evaluation of the form of the acquisition, the relative contribution and rights of the predecessor groups post-closing, and the relative number of shares issued by the Company on acquisition of Arbutus Inc. Under the acquisition method, the consideration transferred is measured at fair value; common shares as consideration are issued at the market price as at the acquisition date. The excess of the purchase price over the preliminary fair value assigned to the net assets acquired has been recorded as goodwill. Acquisition costs were expensed as incurred. The Company recorded $9,656,000 of acquisition costs for the year ended December 31, 2015 (2014 - $462,000).

The Company issued consideration with a total fair value of $381,942,000 on acquisition. Of this consideration, 23,973,315 common shares were issued, which is comprised of 20,347,906 common shares issued without subjects and 3,625,412 common shares issued to Arbutus Inc.’s founding executives and subject to repurchase provisions. The fair value of the common shares issued without subjects has been determined to be the Company’s NASDAQ closing price of $18.26 on the date prior to the acquisition’s consummation, March 4, 2015. The total fair value of the common shares issued subject to repurchase provision has been determined to be $66,196,000, using the Black-Scholes pricing model with assumed risk-free interest rate of 0.74%, volatility of 81%, a zero dividend yield and an expected life of 4 years. Of the total fair value, $9,262,000 has been attributed as pre-combination service and included as part of the total acquisition consideration. The post-combination attribution of $56,934,000 will be recognized as compensation expense over the period of expiry of repurchase provision rights and is not included in the total acquisition consideration. In July 2015, in conjunction with amendments to the employment contracts of Arbutus Inc.’s founding executives, the Company amended the repurchase provision rights period of expiry from August 2018 to August 2017. This amendment results in an acceleration of compensation expense recognized in each subsequent period by approximately $1,900,000 per quarter, effective in Q3 2015. The Company recorded $16,687,000 in stock-based compensation expense related to services performed during the period of expiration of repurchase provision rights from the acquisition date through to December 31, 2015.

As at the acquisition date, 3,625,412 shares were issued and outstanding which were and continue to remain subject to a repurchase provision. Subsequent to the acquisition date and the July 2015 amendment to the repurchase provision rights, the rights expire at a rate of 302,120 on November 30, 2015 and February 29, 2016 and at a rate of 503,552 shares every three months thereafter commencing May 31, 2016.

The Company has further reserved 184,332 shares for the future exercise of Arbutus Inc. stock options. The total fair value of Arbutus Inc. stock options at the date of acquisition has been determined to be $3,287,000, using the Black-Scholes pricing model with an assumed risk-free interest rate of 0.97%, volatility of 78%, a zero dividend yield and an expected life of 8 years, which are consistent with the assumption inputs used by the Company to determine the fair value of its options. Of the total fair value, $1,127,000 has been attributed as pre-combination service and included as part of the total acquisition consideration. The post-combination attribution of $2,160,000 will be recognized as compensation expense over the vesting period of the stock options through to December 2018. The Company has included $463,000 compensation expense related to the vesting of Arbutus Inc. stock options from the acquisition date through to December 31, 2015.

The aggregate fair value of consideration transferred to acquire Arbutus Inc.’s outstanding shares has been determined to be $381,942,000, and has been attributed to fair values of assets acquired and liabilities assumed. The Company has refined the preliminary allocation of the purchase price for intangible assets, goodwill, contingent consideration and deferred tax liability from what was disclosed in prior periods. The following table summarizes the Company’s finalized purchase price allocation as at December 31, 2015:



Consideration paid:
Common shares issued without subjects	$	371,553
Common shares issued subject to repurchase provision	9,262
Common shares issuable for Arbutus Inc. stock options	1,127
	$	381,942

Identifiable assets acquired and liabilities assumed:
Cash	$	324
Prepaid expenses and other assets	116
Accounts receivable	8
Property and equipment	147
Acquired intangible assets	391,649
Goodwill	162,514
Accounts payable and accrued liabilities	(3,580		)
Other non-current liabilities (note 9)	(6,727		)
Deferred income tax liability	(162,509		)
Total purchase price allocation	$	381,942

The fair value of intangible assets is estimated to be $391,649,000. The fair value of each IPR&D asset is estimated using the income approach. The income approach uses valuation techniques to discount future economic benefits attributed to the subject intangible asset to a present value. Present value is based on current market expectations about those future amounts and includes management’s estimates of risk-adjusted future incremental earnings that may be achieved upon regulatory approval, promotion, and distribution associated with the rights and includes estimated cash flows of approximately 20 years and a discount rate of approximately 13.7%. The identifiable intangible assets acquired consist of in-process research and development (IPR&D) HBV assets, as summarized in the table below:



IPR&D – Cyclophilins	$	39,007
IPR&D – Immune Modulators	183,103
IPR&D – Antigen Inhibitors	36,437
IPR&D – cccDNA Sterilizers	133,102
Total IPR&D	$	391,649

All IPR&D acquired is currently classified as indefinite-lived and is not currently being amortized. IPR&D becomes definite-lived upon the completion or abandonment of the associated research and development efforts, and will be amortized from that time over an estimated useful life based on respective patent terms. The fair value of each IPR&D asset will continue to be evaluated on a quarterly basis for indicators of impairment.

Based on the fair values above, an amount of $162,514,000 has been allocated to goodwill, which represents the excess of the purchase price over the fair values assigned to the net assets acquired. Goodwill is attributable to synergies expected to arise after the Company’s acquisition of Arbutus Inc. The full amount of the value of goodwill has been assigned to the entire Company, since management has determined that the Company has only one reporting unit. The goodwill is not deductible for tax purposes, and is not amortized, but will be evaluated for impairment on an annual basis or more often if the Company identifies impairment indicators that would require earlier testing.

Reconciliation of preliminary to final purchase price allocation

During the year ended December 31, 2015, the Company finalized the purchase price allocation and made revisions to certain preliminary estimated fair values of assets acquired and liabilities assumed. The following table presents a summary of revisions and adjustments made to the preliminary estimates as previously disclosed to the finalized purchase price allocation:



	Preliminary Amounts Recognized as of Acquisition Date ⁽¹⁾			Measurement Period Adjustments⁽²⁾			Amounts Recognized as of Acquisition Date (as adjusted)
Purchase Price	$	381,942		$	—		$	381,942

Identifiable assets acquired and liabilities assumed:
Cash	$	324		$	—		$	324
Prepaid expenses and other assets	127			(11		)	116
Accounts receivable	8			—			8
Property and equipment	147			—			147
Acquired intangible assets	389,652			1,997			391,649
Goodwill	155,865			6,649			162,514
Accounts payable and accrued liabilities	(3,580		)	—			(3,580		)
Other non-current liabilities (note 8)	(4,736		)	(1,991		)	(6,727		)
Deferred income tax liability	(155,865		)	(6,644		)	(162,509		)
Total purchase price allocation	$	381,942		$	—		$	381,942


1.	The preliminary purchase price as of the acquisition date of March 4, 2015 as previously disclosed in the notes to consolidated financial statements included in the Company's Quarterly Report on Form 10-Q for the period ended March 31, 2015.


2.	The measurement period is from the acquisition date of March 4, 2015 to the date the Company finalized the purchase price allocation on December 31, 2015.

The measurement period adjustment for intangible assets acquired was made as the Company revised certain royalty rates on future sales of various intangible assets acquired. This resulted in an increase in deferred income tax liability associated with the intangible assets. In addition, the Company revised its preliminary tax rate based on management's revised analysis of a combined federal and state tax rate in the jurisdiction in which the Company expects the deferred tax liability to be settled or realized.

The measurement period adjustment for other non-current liabilities relate to the contingent consideration payable to former Enantigen shareholders upon the achievement of certain regulatory, development and sales milestones, as described in note 9. The adjustment relates to management's revision to the probabilities used in a probability weighted assessment of the likelihood of milestones being met and timing of such payments.

Based on the above measurement period adjustments, the increase to goodwill of $6,649,000 results in a final goodwill allocation of $162,514,000. As described in note 2 and further below, the Company conducts its annual goodwill impairment test on December 31st.

Pro forma information

The amount of net loss of Arbutus Inc. included in the consolidated statements of operations from the acquisition date, through the period ended December 31, 2015 was $13,658,000. Arbutus Inc. did not earn any revenues from the acquisition date through the year-ended December 31, 2015.

The following table presents the unaudited pro forma results for the year ended December 31, 2015 and 2014. The pro forma financial information combines the results of operations of Arbutus, Arbutus Inc., Protiva, Protiva USA, and Enantigen as though the businesses had been combined as of the beginning of fiscal 2014. The pro forma financial information is presented for informational purposes only, and is not indicative of the results of operations that would have been achieved if the merger had taken place at the beginning of fiscal 2014. The pro forma financial information presented includes acquisition costs, amortization charges for acquired tangible assets, impairment charge on acquired intangible assets (as described in note 3b below), but does not include amortization charges for acquired intangible assets as these assets have not yet been put in use.



	Year ended
	December 31,
	2015			2014
Pro forma information
Gross Revenue	$	24,873		$	14,953
Loss from operations	(109,387		)	(51,088		)
Net loss	(67,416		)	(56,491		)
Basic and diluted loss per share	$	(1.38	)	$	(1.24	)

(b) Impairment evaluations for intangible assets and goodwill

The Company evaluates the recoverable amount of intangible assets on an annual basis and performs an annual evaluation of goodwill as of December 31 each year, unless there is an event or change in the business that could indicate impairment and earlier testing.

Impairment of intangible assets

On October 28, 2015, the Company announced that the development of the cyclophilin drug candidate, OCB-030 has been discontinued. The decision was based on extensive preclinical evaluations performed by the Company of OCB-030 and other competitive cyclophilin inhibitors following the acquisition of Arbutus Inc., which concluded that cyclophilins do not play a meaningful role in HBV biology. Although the final conclusion was made subsequent to the period end, it reflected management’s best estimate as at September 30, 2015, and as such, the Company recorded an estimated impairment charge of $37,990,000 and a corresponding income tax benefit of $15,196,000 related to the decrease in deferred tax liability for the discontinuance of OCB-030 in the consolidated statement of operations and comprehensive loss.

As noted above, the Company finalized its purchase price allocation during the fourth quarter of 2015 by making certain revisions to estimates which included adjustments to the fair value of individual intangible assets acquired. The fair value of cyclophilin inhibitors has been adjusted to be $39,007,000 as compared to management's best estimate of $37,990,000 previously written off in the third quarter. The incremental adjustment to fair value of $1,017,000 as well as the corresponding incremental adjustment to income tax benefit of $989,000 are cumulatively reflected in the Company's consolidated statement of operations and comprehensive loss for the year-ended December 31, 2015. For all other IPR&D, fair values of the intangible assets were calculated to be above the respective carrying values; therefore, no impairment was recorded. The following table summarizes the carrying values, net of impairment of the intangible assets as at December 31, 2015:



IPR&D – Cyclophilins	$	—
IPR&D – Immune Modulators	183,103
IPR&D – Antigen Inhibitors	36,437
IPR&D – cccDNA Sterilizers	133,102
Total IPR&D	$	352,642

Annual impairment evaluation of goodwill

On December 31, the Company conducted its annual impairment evaluation of goodwill. Goodwill was recorded as a result of the acquisition of Arbutus Inc. as described in note 3(a), and has a carrying value of $162,514,000. As part of the evaluation of the recoverability of goodwill, the Company has identified only one reporting unit to which the total carrying amount of goodwill has been assigned. The income approach is used to estimate the fair value of the reporting unit, which requires estimating future cash flows and risk-adjusted discount rates. Changes in these estimates and assumptions could materially affect the determination of fair value of the reporting unit and may result in impairment charges in future periods.

As at December 31, 2015, the fair value of the reporting unit exceeded the carrying value of the reporting unit, and as such the second step of the impairment test, which measures the amount of impairment charge, was not required. In addition to the income approach, the Company considered the market capitalization of approximately $242,844,000 as at December 31, 2015. Although the Company’s carrying value of $547,679,000 exceeded the market capitalization, the Company reconciled the income approach determination of fair value with the market capitalization by considering macroeconomic factors, and as such, the Company does not believe that market capitalization appropriately reflected the value of the Company for the purpose of testing goodwill impairment. No impairment charge on goodwill was recorded for the year ended December 31, 2015.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Collaborations, Contracts and Licensing Agreements

12 Months Ended

Dec. 31, 2015

Deferred Revenue Disclosure [Abstract]

Collaborations, contracts and licensing agreements

The following tables set forth revenue recognized under collaborations, contracts and licensing agreements:



	Year ended December 31
	2015		2014		2013
Collaborations and contracts
DoD (a)	$	6,764	$	8,407	$	9,806
Monsanto (b)	4,725		1,080		—
BMS (d)	—		1,741		526
Dicerna (e)	1,820		510		—
Other RNAi collaborators (g)	—		—		93
Total research and development collaborations and contracts	13,309		11,738		10,425
Licensing fees, milestone and royalty payments
Monsanto licensing fees and milestone payments (b)	10,256		2,744		—
Alnylam and Acuitas licensing fees and milestone payments (c)	15		150		5,000
Dicerna licensing fee (e)	1,053		131		—
Spectrum royalty payments (f)	240		190		40
Total licensing fees, milestone and royalty payments	11,564		3,215		5,040
Total revenue	$	24,873	$	14,953	$	15,465

The following table sets forth deferred collaborations and contracts revenue:



	December 31, 2015		December 31, 2014
DoD (a)	$	15	$	313
Monsanto current portion (b)	—		4,245
Dicerna current portion (e)	853		1,221
Deferred revenue, current portion	868		5,779
Monsanto long-term portion (b)	—		8,666
Dicerna long-term portion (e)	213		1,271
Total deferred revenue	$	1,081	$	15,716

(a) Contract with United States Government’s Department of Defense (“DoD”) to develop TKM-Ebola

On July 14, 2010, the Company signed a contract with the DoD to advance TKM-Ebola, an RNAi therapeutic utilizing the Company’s lipid nanoparticle technology to treat Ebola virus infection.

In the initial phase of the contract, funded as part of the Transformational Medical Technologies program, the Company was eligible to receive up to $34,700,000. This initial funding was for the development of TKM-Ebola including completion of preclinical development, filing an Investigational New Drug application with the United States Food and Drug Administration (“FDA”) and completing a Phase 1 human safety clinical trial. On May 8, 2013, the Company announced that the contract had been modified to support development plans that integrate recent advancements in lipid nanoparticle (“LNP”) formulation and manufacturing technologies. The contract modification increased the stage one targeted funding by an additional $6,970,000. On April 22, 2014, the Company and the DoD signed a contract modification to further increase the stage one targeted funding by $2,100,000 to $43,819,000. The additional funding was to compensate the Company for unrecovered overheads related to the temporary stop-work period that occurred in 2012 and to provide additional overhead funding should it be required.

The DoD had the option of extending the contract beyond the initial funding period to support the advancement of TKM-Ebola through to the completion of clinical development and FDA approval. Based on the contract’s budget this would have provided the Company with up to $140,000,000 in funding for the entire program. In December 2014, the DoD exercised an option valued at $7,000,000 to manufacture TKM-Ebola-Guinea, developed by the Company targeting the Ebola-Guinea strain responsible for the current outbreak in West Africa.

Under the contract, the Company is reimbursed for costs incurred, including an allocation of overhead costs, and is paid an incentive fee. At the beginning of the fiscal year, the Company estimates its labor and overhead rates for the year ahead. At the end of the year the actual labor and overhead rates are calculated and revenue is adjusted accordingly. The Company’s actual labor and overhead rates will differ from its estimated rates based on actual costs incurred and the proportion of the Company’s efforts on contracts and internal products versus indirect activities. Within minimum and maximum collars, the amount of incentive fee the Company can earn under the contract varies based on costs incurred versus budgeted costs. During the contractual period, incentive fee revenue and total costs are impacted by management’s estimate and judgments which are continuously reviewed and adjusted as necessary using the cumulative catch-up method. For the years ended December 31, 2014 and 2015, the Company believes it can reliably estimate the final contract costs so has recognized the portion of expected incentive fee which has been earned to date.

On October 1, 2015, the Company received formal notification from the DoD that, due to the unclear development path for TKM-Ebola and TKM-Ebola-Guinea, the Ebola-Guinea Manufacturing and the Ebola-Guinea IND submission statements of work had been terminated, subject to the completion of certain post-termination obligations. The TKM-Ebola portion of the contract was completed in November 2015. The Company is currently conducting contract close out procedures with the DoD.

(b) Option and Services Agreements with Monsanto Company (“Monsanto”)

On January 13, 2014, the Company and Monsanto signed an Option Agreement and a Services Agreement (together, the “Agreements”). Under the Agreements, Monsanto has an option to obtain a license to use the Company’s proprietary delivery technology and related intellectual property for use in agriculture. Over the option period, which is expected to be approximately four years, the Company will provide lipid formulations for Monsanto’s research and development activities, and Monsanto will make certain payments to the Company to maintain its option rights. The maximum potential value of the transaction is $86,200,000 following the successful completion of milestones.

In May 2015, the arrangement was amended to extend the option period by approximately five months, with payments up to $2,000,000 for the extension period. From inception of the contract to December 31, 2015, the Company had received $19,300,000 from Monsanto. The amounts received relate to research services and use of the Company’s technology over the option period, and are recognized as revenue on a straight-line basis over the extended option period.

Following the completion of the Phase A extension period in October 2015, no further research activities were conducted under the arrangement, as Monsanto did not elect to proceed to Phase B of the research plan. As such, the Company revised its estimate of the option period, over which payments received from Monsanto is recognized as revenue, to be from inception to December 31, 2015 as the Company believes it no longer has any further obligations to provide future research activities to Monsanto. This resulted in the full release of Monsanto deferred revenue and a recognition of $14,981,000 in Monsanto revenue for the year-ended December 31, 2015.

Under the Agreements, the Company has established a wholly-owned subsidiary, PADCo. The Company has determined that PADCo is a variable interest entity (“VIE”); however, Monsanto is the primary beneficiary of the arrangement. PADCo was established to perform research and development activities, which have been funded by Monsanto in return for a call option to acquire the equity or all of the assets of PADCo. At any time during the option period, Monsanto may choose to exercise its option, in which case Monsanto would pay the Company an option exercise fee and would receive a worldwide, exclusive right to use the Company’s proprietary delivery technology in the field of agriculture. Monsanto may elect to terminate this option at their discretion. The Company retains all rights to therapeutics uses of all current intellectual property and intellectual property developed under the Agreements. The Company’s initial investment is not significant, and the Company has no implied or unfunded commitments and the maximum exposure to loss is limited to the amount of investment in the entity. The Company has included its investment in PADCo in other assets. There were no significant assets or liabilities for PADCo as at December 31, 2015. There was no equity income or loss with respect to PADCo recorded for the periods ended December 31, 2014 and December 31, 2015. In March 2016, Monsanto exercised its option to acquire 100% of the outstanding shares of PADCo and will pay the Company an exercise fee of $1,000,000 - refer to note 13 for the subsequent event.

Milestone receipts and payments

In November 2013, Alnylam initiated a Phase III trial with ALN-TTR02, also known as patisiran, and the associated $5,000,000 development milestone was paid to the Company in December 2013. In addition, the Company earned a $150,000 milestone in March 2014 from Acuitas (formerly AlCana Technologies, Inc.) subsequent to Acuitas receiving a milestone payment from Alnylam with respect to Alnylam initiating a Phase III trial for ALN-TTR02.

In November 2013, the Company initiated Phase I/II clinical trial for TKM-PLK1, resulting in a milestone payment of $375,000 to Alnylam.

Arbitration with Alnylam and Ascletis Pharmaceuticals (Hangzhou) Co. Ltd. (“Ascletis”)

On June 21, 2013, the Company transferred manufacturing process technology to Ascletis to enable them to produce ALN-VSP, a product candidate licensed to them by Alnylam. The Company believed that under its licensing agreement with Alnylam, the technology transfer to Ascletis triggered a $5,000,000 milestone obligation from Alnylam to the Company. However, Alnylam demanded a declaration that the Company had not yet met its milestone obligations. The Company disputed Alnylam’s position. To remedy this dispute, the Company and Alnylam commenced arbitration proceedings as provided for under the agreement. The hearing date for this arbitration took place in May 2015, and in March 2016, the arbitration proceeding with Alnylam has concluded resulting in no milestone payment to the Company. The Company has not recorded any revenue in respect of this milestone for the year-ended December 31, 2015.

(d) Bristol-Myers Squibb (“BMS”) collaboration

On May 10, 2010 the Company announced the expansion of its research collaboration with BMS. Under the new agreement, BMS uses small interfering RNA (“siRNA”) molecules formulated by the Company in LNP technology to silence target genes of interest. BMS is conducting the preclinical work to validate the function of certain genes and share the data with the Company. The Company can use the preclinical data to develop RNAi therapeutic drugs against the therapeutic targets of interest. The Company received $3,000,000 from BMS concurrent with the signing of the agreement and recorded the amount as deferred revenue. The Company is required to provide a pre-determined number of LNP batches over the four-year agreement. BMS has a first right to negotiate a licensing agreement on certain RNAi products developed by the Company that evolve from BMS validated gene targets.

Revenue from the May 10, 2010 agreement with BMS is being recognized as the Company produces the related LNP batches.

Revenue earned for the year-ended December 31, 2014 relates to batches shipped to BMS during the period. In August 2014, the agreement expired and both companies' obligations under the agreement ended.

(e) License and Development and Supply Agreement with Dicerna Pharmaceuticals, Inc. (“Dicerna”)

On November 16, 2014, the Company signed a License Agreement and a Development and Supply Agreement (together, the “Agreements”) with Dicerna to development, manufacture, and commercialization of products directed to treatment of Primary Hyperoxaluria 1 (“PH1”), In consideration for the rights granted under the Agreements, Dicerna paid the Company an upfront cash payment of $2,500,000. The Company is also entitled to receive payments from Dicerna on the manufacturing and services provided, as well as further payments with the achievement of development and regulatory milestones of $22,000,000 in aggregate, and potential commercial royalties. Further, under the Agreements, a joint development committee has been established to provide guidance and direction on the progression of the collaboration.

The Company determined the deliverables under the Agreements included the rights granted, participation in the joint development committee, materials manufactured and other services provided, as directed under the joint development committee. The license and participation in the joint development committee have been determined by the Company to not have standalone value due to the uniqueness of the subject matter under the Agreements. Therefore, these deliverables are treated as one unit of accounting and recognized as revenue over the performance period, which the Company has estimated to be approximately 28 months as at December 31, 2015.

The Company has determined that manufacturing services and other services provided have standalone value, as a separate statement of work is executed and invoiced for each manufacturing or service work order. The relative fair values are determined as a batch price or fee is estimated upon the execution of each work order, with actual expenditures charged at comparable market rates with embedded margins on each work order.

Manufacturing work orders are invoiced at the time of execution of the work order, at the initiation of manufacture, and at the release of materials. The Company has deferred the recognition of revenue on all cash deposit payments received for manufacturing work orders until acceptance of inventory. Revenue from service work orders is recognized as the services are performed.

The Company believes the development and regulatory milestones are substantive, due to the existence of substantive uncertainty upon the execution of the arrangement, and that the achievement of the development and regulatory events are based in part on the Company’s performance and the occurrence of a specific outcome resulting from performance. The Company has not received any milestone payments to date.

(f) Agreements with Spectrum Pharmaceuticals, Inc. (“Spectrum”)

On May 6, 2006, the Company signed a number of agreements with Talon Therapeutics, Inc. (“Talon”, formerly Hana Biosciences, Inc.) including the grant of worldwide licenses (the “Talon License Agreement”) for three of the Company’s chemotherapy products, Marqibo®, Alocrest ™ (Optisomal Vinorelbine) and Brakiva ™ (Optisomal Topotecan).

On August 9, 2012, the Company announced that Talon had received accelerated approval for Marqibo from the FDA for the treatment of adult patients with Philadelphia chromosome negative acute lymphoblastic leukemia in second or greater relapse or whose disease has progressed following two or more anti-leukemia therapies. Marqibo is a liposomal formulation of the chemotherapy drug vincristine. In the year ended December 31, 2012, the Company received a milestone of $1,000,000 based on the FDA’s approval of Marqibo and will receive royalty payments based on Marqibo’s commercial sales. There are no further milestones related to Marqibo but the Company is eligible to receive total milestone payments of up to $18,000,000 on Alocrest and Brakiva.

Talon was acquired by Spectrum in July 2013. The acquisition did not affect the terms of the license between Talon and the Company. On September 3, 2013, Spectrum announced that they had shipped the first commercial orders of Marqibo. In the year ended December 31, 2015, the Company recorded $240,000 in Marqibo royalty revenue (2014 - $190,000, 2013 -$40,000). In the year ended December 31, 2015, the Company accrued $6,000 in royalties due to TPC in respect of the Marqibo royalty earned by the Company (see note 9).

(g) Other RNAi collaborators

The Company had active research agreements with a number of other RNAi collaborators.

Property and Equipment

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Property and equipment



December 31, 2015	Cost		Accumulated depreciation			Net book value
Lab equipment	$	5,910	$	(3,748	)	$	2,162
Leasehold improvements	4,681		(4,189		)	492
Computer hardware and software	2,014		(1,487		)	527
Furniture and fixtures	307		(305		)	2
	$	12,912	$	(9,729	)	$	3,183



December 31, 2014	Cost		Accumulated depreciation			Net book value
Lab equipment	$	5,021	$	(4,451	)	$	570
Leasehold improvements	5,281		(4,796		)	485
Computer hardware and software	2,293		(1,588		)	705
Furniture and fixtures	364		(364		)	—
	$	12,959	$	(11,199	)	$	1,760

As at December 31, 2015, all of the Company’s property and equipment are currently in use and no impairment has been recorded.

Share Capital

12 Months Ended

Dec. 31, 2015

Stockholders' Equity Note [Abstract]

Share capital

(a) Financing

On October 22, 2013, the Company completed an underwritten public offering of 3,750,000 common shares, at a price of $8.00 per share, representing gross proceeds of $30,000,000. On November 1, 2013, the offering’s underwriter completed the exercise of its over-allotment option to purchase a further 562,500 shares at $8.00 bringing the aggregate financing gross proceeds to $34,500,000. The cost of the financing, including commissions and professional fees, was $2,462,000, resulting in net proceeds of $32,038,000.

On March 26, 2014, the Company completed an underwritten public offering of 2,125,000 common shares, at a price of $28.50 per share, representing gross proceeds of $60,562,000. The Company also granted the underwriters a 30-day option to purchase an additional 318,750 shares for an additional $9,084,000 to cover any over-allotments. The underwriters did not exercise the option. The cost of financing, including commissions and professional fees, was $4,085,000, resulting in net proceeds of $56,477,000.

On March 25, 2015, the Company announced that it had completed an underwritten public offering of 7,500,000 common shares, at a price of $20.25 per share, representing gross proceeds of $151,875,000. The Company also granted the underwriters a 30-day option to purchase an additional 1,125,000 shares for an additional $22,781,000 to cover any over-allotments. The underwriters did not exercise the option. The cost of financing, including commissions and professional fees, was $9,700,000, resulting in net proceeds of $142,177,000.

(b) Authorized share capital

The Company’s authorized share capital consists of an unlimited number of common and preferred shares without par value.

During the year ended December 31, 2015, there were 18,750 warrants exercised for $42,000 in cash (December 31, 2014 – 610,478 warrants for $1,583,000) and no warrants were exercised using the cashless exercise provision (December 31, 2014 – 6,000 warrants for 5,285 common shares).

The following table summarizes the Company’s warrant activity for the years ended December 31, 2015 and 2014:



	Common shares purchasable upon exercise of warrants		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Range of exercise prices (C$)				Range of exercise prices (US$)				Weighted average remaining contractual life (years)	Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2013	1,014,728		$	2.90	$	2.72	$2.60	—	$	3.35	$2.44	—	$	3.15	2.7	$	5,635	$	5,298
Exercised	(616,478	)	3.09		2.80		2.60	—	3.35		2.35	—	3.03
Balance, December 31, 2014	398,250		2.95		2.67		2.60	—	3.35		2.35	—	3.03		1.8	5,902		5,343
Exercised	(18,750	)	2.88		2.25		2.60	—	3.35		2.03	—	2.62
Balance, December 31, 2015	379,500		$	2.95	$	2.13	$2.60	—	$	3.35	$2.03	—	$	2.62	0.8	$	1,217	$	879

The aggregate intrinsic value in the table above is calculated based on the difference between the exercise price of the warrants and the quoted price of the Company’s common stock as of the reporting date.

All of the Company’s warrants were exercisable as of December 31, 2015.

The weighted average Black-Scholes option-pricing assumptions and the resultant fair values are as follows for warrants outstanding at December 31, 2015 and 2014 are as follows:



	As at December 31
	2015			2014
Dividend yield	—		%	—		%
Expected volatility	49.07		%	85.22		%
Risk-free interest rate	0.48		%	1.00		%
Expected average term (years)	0.6 years			0.5 years
Fair value of warrants outstanding	$	2.33		$	12.80
Aggregate fair value of warrants outstanding	$	883		$	5,099
Number of warrants outstanding	379,500			398,250

The value of the Company’s warrants are particularly sensitive to changes in the Company’s share price and the estimated share price volatility.

(d) Stock-based compensation

The Company has six share-based compensation plans; the “2007 Plan”, the “2011 Plan”, two “Designated Plans” (together, the “Arbutus Plans”), the “Protiva Option Plan”, and the "OnCore Option Plan" (see note 3 above).

On June 22, 2011, the shareholders of the Company approved an omnibus stock-based compensation plan (the “2011 Plan”). The Company’s pre-existing 2007 Plan was limited to the granting of stock options as equity incentive awards whereas the 2011 Plan also allows for the issuance of tandem stock appreciation rights, restricted stock units and deferred stock units (collectively, and including options, referred to as “Awards”). The 2011 Plan replaces the 2007 Plan. The 2007 Plan will continue to govern the options granted thereunder. No further options will be granted under the Company’s 2007 Plan.

Under the Company’s 2007 Plan the Board of Directors granted options to employees, directors and consultants of the Company. The exercise price of the options was determined by the Company’s Board of Directors but was always at least equal to the closing market price of the common shares on the day preceding the date of grant and the term of options granted did not exceed 10 years. The options granted generally vested over three years for employees and immediately for directors.

Under the Company’s 2011 Plan the Board of Directors may grant options, and other types of Awards, to employees, directors and consultants of the Company. The exercise price of the options is determined by the Company’s Board of Directors but will be at least equal to the closing market price of the common shares on the day preceding the date of grant and the term may not exceed 10 years. Options granted generally vest over three years for employees and immediately for directors.

Additionally, the Company granted a total of 200,000 options in 2013 to two executive officers in conjunction with their new appointments as executive officers. These options were granted in accordance with the policies of the Toronto Stock Exchange and pursuant to newly designated share compensation plans (the “Designated Plans”). The Designated Plans are governed by substantially the same terms as the 2011 Plan. Hereafter, information on options governed by the 2007 Plan, the 2011 Plan, and the Designated Plans is presented on a consolidated basis as the terms of the four plans are similar. Information on the Protiva Option Plan and the OnCore Option Plan is presented separately.

At the Company’s annual general and special meeting of shareholders on May 8, 2014 and July 9, 2015, the shareholders of the Company approved respectively, a 800,000 and a 3,500,000 increase in the number of stock-based compensation awards that the Company is permitted to issue.

Stock option activity for the Arbutus Plans



	Number of optioned common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2012	1,648,846		$	4.54	$	4.54	$	2,300	$	2,301
Options granted	270,250		7.52		7.30
Options exercised	(124,246	)	3.22		3.13		551		535
Options forfeited, canceled or expired	(64,085	)	21.87		21.23
Balance, December 31, 2013	1,730,765		4.45		4.32		7,030		6,826
Options granted	431,125		13.63		12.34
Options exercised	(622,752	)	4.62		4.18		7,650		6,926
Options forfeited, canceled or expired	(9,000	)	8.20		7.42
Balance, December 31, 2014	1,530,138		6.95		6.29		16,573		15,004
Options granted	1,309,625		N/A		16.57
Options exercised	(398,293	)	5.03		3.93		6,887		5,386
Options forfeited, canceled or expired	(151,207	)	19.29		15.09
Balance, December 31, 2015	2,290,263		$	15.53	$	11.22	$	1,376	$	994

Options under the Arbutus Plans expire at various dates from March 28, 2016 to December 2, 2025.

The following table summarizes information pertaining to stock options outstanding at December 31, 2015 under the Arbutus Plans:



			Options outstanding December 31, 2015				Options exercisable December 31, 2015
Range of Exercise prices (US$)			Number of options outstanding	Weighted average remaining contractual life (years)	Weighted average exercise price (US$)		Number of options exercisable	Weighted average exercise price (US$)
$1.08	to	$1.37	102,800	4.9	$	1.24	102,800	$	1.24
$1.52	to	$1.88	120,475	5.8	1.66		120,475	1.66
$2.17	to	$2.78	83,000	2.9	2.56		83,000	2.56
$3.24	to	$4.70	288,960	5.4	3.84		268,900	3.83
$5.10	to	$7.50	261,923	7.7	6.33		175,112	6.12
$8.38	to	$10.04	176,813	8.7	9.35		99,189	9.24
$10.69	to	$13.39	129,417	8.2	11.93		79,252	11.90
$13.40	to	$17.57	1,126,875	9.2	17.02		10,002	17.57
$1.08	to	$17.57	2,290,263	7.9	$	11.22	938,730	$	4.98

At December 31, 2015, there were 938,730 options exercisable (December 31, 2014 - 1,088,908; December 31, 2013 – 1,377,091) . The weighted average remaining contractual life of exercisable options as at December 31, 2015 was 6.1 years.

The aggregate intrinsic value of in-the-money options exercisable at December 31, 2015 was $994,000.

A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2015 is as follows:



	Number of optioned common shares		Weighted average fair value (C$)		Weighted average fair value (US$)
Non-vested at December 31, 2014	441,230		$	9.30	$	8.42
Options granted	1,309,625		15.20		11.89
Options vested	(250,461	)	8.77		6.86
Non-vested options forfeited	(148,853	)	14.27		11.16
Non-vested at December 31, 2015	1,351,541		$	15.69	$	11.34

The weighted average remaining contractual life for options expected to vest at December 31, 2015 was 9.1 years and the weighted average exercise price for these options was $15.54 (C$21.51) per share.

The aggregate intrinsic value of options expected to vest as at December 31, 2015 was $10,000 (December 31, 2014 - $2,626,000; December 31, 2013 -$943,000).

The total fair value of options that vested during the year ended December 31, 2015 was $1,718,000 (2014 - $2,505,000; 2013 -$955,000).

Valuation assumptions for the Arbutus Plans

On March 3, 2015, the Company de-listed from the Toronto Stock Exchange. All stock options granted after March 3, 2015 were denominated in US dollars based on the Company's stock price on the NASDAQ. The methodology and assumptions used to estimate the fair value of stock options at date of grant under the Black-Scholes option-pricing model remain unchanged. Assumptions on the dividend yield are based on the fact that the Company has never paid cash dividends and has no present intention to pay cash dividends. Assumptions about the Company’s expected stock-price volatility are based on the historical volatility of the Company’s publicly traded stock. The risk-free interest rate used for each grant is equal to the zero coupon rate for instruments with a similar expected life. Expected life assumptions are based on the Company’s historical data. Based on an analysis of its historical forfeitures, the Company has applied a forfeiture rate to all unvested options held as of December 31, 2015. The Company will record additional expense if the actual forfeitures are lower than estimated and will record a recovery of prior expense if the actual forfeitures are higher than estimated. The weighted average option pricing assumptions and the resultant fair values are as follows:



	Year ended December 31
	2015		2014		2013

Dividend yield	—	%	—	%	—	%
Expected volatility	76.88	%	101.08	%	111.61	%
Risk-free interest rate	1.10	%	2.25	%	2.39	%
Expected average option term	7.5 years		8.8 years		9.6 years

Protiva Option Plan

On May 30, 2008, as a condition of the acquisition of Protiva Biotherapeutics Inc., a total of 350,457 common shares of the Company were reserved for the exercise of 519,073 Protiva share options (“Protiva Options”). The Protiva Options have an exercise price of C$0.30, were fully vested and exercisable as of May 30, 2008. As at December 31, 2015, the outstanding options expire at various dates from April 3, 2017 to March 1, 2018 and upon exercise each option will be converted into approximately 0.6752 shares of the Company (the same ratio at which Protiva common shares were exchanged for Company common shares at completion of the acquisition of Protiva). The Protiva Options are not part of the Arbutus Plans and the Company is not permitted to grant any further Protiva Options.

The following table sets forth outstanding options under the Protiva Option Plan:



	Number of Protiva Options		Equivalent number of Company common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)
Balance, December 31, 2012	475,885		321,299		$	0.30	0.30
Options exercised	(2,000	)	(1,350	)	0.30		0.29
Options forfeited, canceled or expired	(1,000	)	(675	)	0.30		0.29
Balance, December 31, 2013	472,885		319,274		0.30		0.29
Options exercised	(38,145	)	(25,754	)	0.30		0.27
Options forfeited, canceled or expired	(1,000	)	(675	)	0.30		0.27
Balance, December 31, 2014	433,740		292,845		0.30		0.27
Options exercised	(358,675	)	(242,164	)	0.30		0.23
Options forfeited, canceled or expired	(8,065	)	(5,445	)	0.30		0.23
Balance, December 31, 2015	67,000		45,236		$	0.30	$	0.22

The weighted average remaining contractual life of exercisable Protiva Options as at December 31, 2015 was 1.8 years.

The aggregate intrinsic value of Protiva Options outstanding at December 31, 2015 was $187,000. The intrinsic value of Protiva Options exercised in the year ended December 31, 2015 was $1,249,000 (2014 - $378,000; 2013 -$8,000).

OnCore Option Plan

As described in note 3 above, as at the acquisition date, the Company reserved 184,332 shares for the future exercise of OnCore (Arbutus Inc.) stock options. The total fair value of OnCore stock options at the date of acquisition has been determined to be $3,287,000, using the Black-Scholes pricing model with an assumed risk-free interest rate of 0.97%, volatility of 78%, a zero dividend yield and an expected life of 8 years, which are consistent with the assumption inputs used by the Company to determine the fair value of its options. Of the total fair value, $1,127,000 has been attributed as pre-combination service and included as part of the total acquisition consideration. The post-combination attribution of $2,160,000 will be recognized as compensation expense over the vesting period of the stock options through to December 2018.

Following the merger, the Company is not permitted to grant any further options under the OnCore Option Plan. The Company has included $463,000 of compensation expense related to the vesting of Arbutus Inc. stock options from the acquisition date through to December 31, 2015, which includes an estimated forfeiture rate consistent with the Company's forfeiture estimate under the Arbutus Plans.

The following table sets forth outstanding options under the OnCore Option Plan:



	Number of OnCore Options	Equivalent number of Company common shares	Weighted average exercise price (US$)
Balance, March 4, 2015	183,040	184,332	$	0.57
Options exercised	—	—	N/A
Options forfeited, canceled or expired	—	—	N/A
Balance, December 31, 2015	183,040	184,332	$	0.57

At December 31, 2015, there were 86,658 OnCore options (87,269 Arbutus equivalent) exercisable with a weighted average exercise price of $0.57. The weighted average remaining contractual life of exercisable options as at December 31, 2015 was 8.9 years. The aggregate intrinsic value of in-the-money options exercisable at December 31, 2015 was $337,000.

A summary of the OnCore Option Plan's non-vested stock option activity and related information for the period from acquisition to December 31, 2015 is as follows:



	Number of OnCore Options		Equivalent number of Company common shares		Weighted average fair value (US$)
Non-vested at March 4, 2015	128,510		129,417		$	16.42
Options vested	(32,128	)	(32,354	)	16.42
Non-vested options forfeited	—		—		N/A
Non-vested at December 31, 2015	96,382		97,063		$	16.42

The weighted average remaining contractual life for options expected to vest at December 31, 2015 was 8.9 years and the weighted average exercise price for these options was $0.57 per share.

The aggregate intrinsic value of options expected to vest as at December 31, 2015 was $695,000.

The total fair value of options that vested during the period from acquisition on March 4, 2015 to December 31, 2015 was $620,000.

Stock-based compensation expense

Total stock-based compensation expense is comprised of: (1) the vesting options awarded to employees under the Arbutus and OnCore option plans calculated in accordance with the fair value method as described above; and (2) the expiration of repurchase rights related to the post-combination service portion of the total fair value of shares issued to Arbutus Inc.'s employees as described in note 3 above.

The total stock-based compensation has been recorded in the consolidated statement of operations and comprehensive income (loss) as follows:



	Year ended December 31
	2015		2014		2013
Research, development, collaborations and contracts expenses	$	7,868	$	2,343	$	622
General and administrative expenses	14,225		940		281
Total	$	22,093	$	3,283	$	903

At December 31, 2015, there remains $11,972,000 of unearned compensation expense related to unvested employee stock options to be recognized as expense over a weighted-average period of approximately 16 months, as well as a remaining $35,967,000 unearned compensation expense related to unexpired repurchase rights on shares issued to Arbutus Inc. employees to be recognized as expense over a weighted average period of approximately 12 months.

Awards outstanding and available for issuance

Combining all of the Company’s share-based compensation plans, at December 31, 2015, the Company has 2,519,831 options outstanding and a further 3,135,980 Awards available for issuance.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Paragraph 5
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 210
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-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (SAB TOPIC 4.C)
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph d
-Article 4

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Article 4

Reference 18: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

Reference 19: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

+ Details

Government Grants and Refundable Investment Tax Credits	12 Months Ended
Government Grants and Refundable Investment Tax Credits	Dec. 31, 2015
Government Grants And Refundable Investment Tax Credits [Abstract]
Government grants and refundable investment tax credits	Government grants and refundable investment tax credits Government grants and refundable investment tax credits have been recorded as a reduction in research and development expenses. (a) Government grants On December 22, 2014, the Company entered into a Manufacturing and Clinical Trial Agreement with the University of Oxford to provide the new TKM-Ebola-Guinea therapeutic product for clinical studies in West Africa. The University of Oxford is the representative of the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC), who conducted clinical studies of TKM-Ebola-Guinea in Ebola virus infected patients, with funding provided by the Wellcome Trust. In January 2015, the Company received $1,098,000 from ISARIC for materials manufactured and used in the March 2015 TKM-Ebola-Guinea Phase II single arm trial conducted in Sierra Leone. In June 2015, the Company announced closing of the enrollment for the trial as it reached a futility boundary, which was a predefined statistical endpoint. No further funding is expected under this grant. Government grants for the year ended December 31, 2015 include $1,245,000 in funding from the U.S. National Institutes of Health (2014 - $172,000). (b) Refundable investment tax credits The Company’s estimated claim for refundable Scientific Research and Experimental Development investment tax credits for the year ended December 31, 2015 is $196,000 (2014 - $52,000).

Income Taxes

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Income taxes

Income tax (recovery) expense varies from the amounts that would be computed by applying the combined Canadian federal and provincial income tax rate of 26% (2014 - 26%; 2013 – 26%) to the loss before income taxes as shown in the following tables:



	Year ended December 31,
	2015			2014			2013
Computed taxes (recoveries) at Canadian federal and provincial tax rates	$	(20,100	)	$	(10,097	)	$	(3,486	)
Differences due to change in enacted tax rates	—			—			(9		)
Permanent and other differences	8,113			3,498			1,088
Change in valuation allowance - other	3,676			6,599			2,407
Difference due to income taxed at foreign rates	(7,874		)	—			—
Deferred income tax recovery	$	(16,185	)	$	—		$	—

As at December 31, 2015, the Company has investment tax credits available to reduce Canadian federal income taxes of $7,969,000 (December 31, 2014 - $7,866,000) and provincial income taxes of $3,869,000 (December 31, 2014 - $3,401,000), expiring between 2027 and 2035. In addition, the Company has research and development credits of $483,000 available for indefinite carry-forward, which can be used to reduce future taxable income in the U.S.

At December 31, 2015, the Company has scientific research and experimental development expenditures of $51,823,000 (December 31, 2014 - $49,907,000) available for indefinite carry-forward and $24,745,000 (December 31, 2014 - $25,301,000) of net operating losses due to expire between 2027 and 2035 and which can be used to offset future taxable income in Canada.

As at December 31, 2015, the Company has $17,235,000 of net operating losses due to expire between 2030 and 2035, which can be used to offset future taxable income in the U.S. Future use of a portion of the U.S. loss carry-forwards is subject to limitations under the Internal Revenue Code Section 382. As a result of ownership changes occurred on October 1, 2014 and March 4, 2015, the Company's ability to use these losses may be limited. Losses incurred to date may be further limited if a subsequent change in control occurs.

On November 23, 2011, the Company was registered as a corporation under the Business Activity Act in the province of British Columbia. Under this program, provincial corporation tax charged on foreign income earned from the Company’s patents will be eligible for a 75% tax refund up to a maximum of C$8,000,000. Significant components of the Company’s deferred tax assets are shown below:



	As at December 31,
	2015			2014
Deferred tax assets:
Non-capital loss carryforwards	$	13,932		$	6,578
Research and development deductions	13,474			14,006
Book amortization in excess of tax	2,142			2,745
Share issue costs	777			1,195
Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes	281			4,086
Tax value in excess of accounting value in lease inducements	77			65
Federal investment tax credits	6,303			5,821
Provincial investment tax credits	3,879			3,322
In-process research and development	(146,324		)	—
Upfront license fees	629			—
Total deferred tax assets	(104,830		)	37,818
Valuation allowance	(41,494		)	(37,818		)
Net deferred tax assets	$	(146,324	)	$	—

The comparative figures in the above table have been recast to increase the deferred tax assets before valuation allowance by $8,424,000 and the valuation allowance by $8,424,000 as at December 31, 2014 to be consistent with current year's disclosure. The comparative figures in the income tax expense reconciliation table have also been recast to reflect these changes. These adjustments have no impact on the consolidated financial position, consolidated results of operations or the consolidated cash flows.

Contingencies and Commitments

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Contingencies and commitments

Property lease

The minimum rent and estimated operating cost commitment, net of lease inducements, is as follows:



Year ended December 31, 2016	$	1,229,000
Year ended December 31, 2017	938,000
Year ended December 31, 2018	938,000
Year ended December 31, 2019	547,000
	$	3,652,000

The Company’s lease expense, for the year ended December 31, 2015 of $1,158,000 has been recorded in the consolidated statements of operations and comprehensive loss (2014 of $1,133,000; 2013 -$1,225,000).

Product development partnership with the Canadian Government

The Company entered into a Technology Partnerships Canada (TPC) agreement with the Canadian Federal Government on November 12, 1999. Under this agreement, TPC agreed to fund 27% of the costs incurred by the Company, prior to March 31, 2004, in the development of certain oligonucleotide product candidates up to a maximum contribution from TPC of $7,179,000 (C$9,330,000). As at December 31, 2015, a cumulative contribution of $2,675,000 (C$3,702,000) had been received and the Company does not expect any further funding under this agreement. In return for the funding provided by TPC, the Company agreed to pay royalties on the share of future licensing and product revenue, if any, that is received by the Company on certain non-siRNA oligonucleotide product candidates covered by the funding under the agreement. These royalties are payable until a certain cumulative payment amount is achieved or until a pre-specified date. In addition, until a cumulative amount equal to the funding actually received under the agreement has been paid to TPC, the Company agreed to pay 2.5% royalties on any royalties the Company receives for Marqibo. For the year ended December 31, 2015, the Company earned royalties on Marqibo sales in the amount of $240,000 (see note 4(f)), resulting in $6,000 recorded by the Company as royalty payable to TPC (2014 - $190,000; 2013 -$1,000). The cumulative amount paid or accrued up to December 31, 2015 was $12,000, resulting in the contingent amount due to TPC being $2,664,000 (C$3,687,000).

License agreement with Marina Biotech, Inc. (“Marina”)

On November 29, 2012 the Company announced a worldwide, non-exclusive license to a novel RNAi payload technology called Unlocked Nucleobase Analog (“UNA”) from Marina for the development of RNAi therapeutics.

UNA technology can be used in the development of RNAi therapeutics, which treat disease by silencing specific disease causing genes. UNAs can be incorporated into RNAi drugs and have the potential to improve them by increasing their stability and reducing off-target effects.

Under the license agreement the Company paid Marina an upfront fee of $300,000. A further license payment of $200,000 was paid in 2013 and the Company will make milestone payments of up to $3,250,000 and royalties on each product developed by the Company that uses Marina’s UNA technology. The payments to Marina are expensed to research, development, collaborations and contracts expense.

Effective August 9, 2013, Marina’s UNA technology was acquired by Arcturus Therapeutics, Inc. (“Arcturus”) and the UNA license agreement between the Company and Marina was assigned to Arcturus. The terms of the license are otherwise unchanged. On December 22, 2014, the Company received clearance from Health Canada to conduct a Phase I Clinical Study with TKM-HBV, which utilizes Arcturus’ UNA technology. The dosing of first subject in the Phase I clinical trial of TKM-HBV occurred in January 2015, which resulted in a milestone payment of $250,000 to Arcturus.

Arbitration with the University of British Columbia (“UBC”)

Certain early work on lipid nanoparticle delivery systems and related inventions was undertaken at UBC. These inventions are licensed to the Company by UBC under a license agreement, initially entered in 1998 as amended in 2001, 2006 and 2007. The Company has granted sublicenses under the UBC license to Alnylam as well as to Talon. Alnylam has in turn sublicensed back to the Company under the licensed UBC patents for discovery, development and commercialization of RNAi products. In 2009, the Company entered into a supplemental agreement with UBC, Alnylam and Acuitas, in relation to a separate research collaboration to be conducted among UBC, Alnylam and Acuitas to which the Company has license rights. The settlement agreement signed in late 2012 to resolve the litigation among the Company, Alnylam, and Acuitas, provided for the effective termination of all obligations under such supplemental agreement as between and among all litigants (see note 4(c)).

On November 10, 2014, UBC filed a notice of arbitration against the Company and on January 16, 2015, filed a Statement of Claim, which alleges entitlement to $3,500,000 in allegedly unpaid royalties based on publicly available information, and an unspecified amount based on non-public information. UBC also seeks interest and costs, including legal fees. The Company is currently disputing UBC’s allegations, and no dates have been scheduled for this arbitration. However, the Company notes that arbitration is subject to inherent uncertainty and an arbitrator could rule against the Company. The Company has not recorded an estimate of the possible loss associated with this arbitration, due to the uncertainties related to both the likelihood and amount of any possible loss or range of loss. However, the defense of arbitration and related matters are costly and may divert the attention of the Company’s management and other resources that would otherwise be engaged in other activities. Costs related to the arbitration have been recorded by the Company as incurred.

Contingent consideration from OnCore acquisition of Enantigen and License Agreements between Enantigen and Blumberg and Drexel

In October 2014, OnCore acquired all of the outstanding shares of Enantigen pursuant to a stock purchase agreement. Through this transaction, OnCore acquired a HBV surface antigen secretion inhibitor program and a capsid assembly inhibitor program, each of which are now assets of Arbutus, following the Company’s merger with Arbutus Inc. - see note 3.

Under the stock purchase agreement, OnCore agreed to pay up to a total of $21,000,000 to Enantigen’s selling stockholders upon the achievement of certain triggering events related to Enantigen’s two programs in pre-clinical development related to HBV therapies. The first triggering event is the enrollment of first patient in Phase 1b clinical trial in HBV patients, which the Company does not expect to occur in the next twelve-month period.

The regulatory, development and sales milestone payments have an estimated fair value of approximately $6,727,000 as at the date of acquisition of Arbutus Inc., and have been treated as contingent consideration payable in the purchase price allocation (note 3), based on information available at the date of acquisition, using a probability weighted assessment of the likelihood the milestones would be met and the estimated timing of such payments, and then the potential contingent payments were discounted to their present value using a probability adjusted discount rate that reflects the early stage nature of the development program, time to complete the program development, and overall biotech indices.

Contingent consideration is considered as a financial liability, and measured at its fair value at each reporting period with any changes in fair value from the previous reporting period recorded in the statement of operations and comprehensive loss. For the period ended December 31, 2015, the Company performed an evaluation of the fair value of the contingent consideration using the probability weighted assessment of likelihood of milestone payments as described above. The Company determined the fair value of the contingent consideration has increased by $770,000 to $7,497,000 and the increase in fair value has been recorded in other losses in the statement of operations and comprehensive loss for the year-ended December 31, 2015.

Drexel and Blumberg

In February 2014, OnCore entered into a license agreement with Blumberg and Drexel that granted an exclusive, worldwide, sub-licensable license to three different compound series: cccDNA inhibitors, capsid assembly inhibitors and HCC inhibitors.

In partial consideration for this license, OnCore paid a license initiation fee of $150,000 and issued warrants to Blumberg and Drexel. Under this license agreement, OnCore also agreed to pay up to $3,500,000 in development and regulatory milestones per licensed compound series, up to $92,500,000 in sales performance milestones per licensed product, and royalties in the mid-single digits based upon the proportionate net sales of licensed products in any commercialized combination. The Company is obligated to pay Blumberg and Drexel a double digit percentage of all amounts received from the sub-licensees, subject to customary exclusions.

In November 2014, OnCore entered into an additional license agreement with Blumberg and Drexel pursuant to which it received an exclusive, worldwide, sub-licensable license under specified patents and know-how controlled by Blumberg and Drexel covering epigenetic modifiers of cccDNA and STING agonists. In consideration for these exclusive licenses, OnCore made an upfront payment of $50,000. Under this agreement, the Company will be required to pay up to $1,000,000 for each licensed product upon the achievement of a specified regulatory milestone and a low single digit royalty, based upon the proportionate net sales of compounds covered by this intellectual property in any commercialized combination. The Company is also obligated to pay Blumberg and Drexel a double digit percentage of all amounts received from its sub-licensees, subject to exclusions.

Research Collaboration and Funding Agreement with Blumberg

In October 2014, Arbutus Inc. entered into a research collaboration and funding agreement with Blumberg under which the Company will provide $1,000,000 per year of research funding for three years, renewable at the Company’s option for an additional three years, for Blumberg to conduct research projects in HBV and liver cancer pursuant to a research plan to be agreed upon by the parties. Blumberg has exclusivity obligations to Arbutus with respect to HBV research funded under the agreement. In addition, the Company has the right to match any third party offer to fund HBV research that falls outside the scope of the research being funded under the agreement. Blumberg has granted the Company the right to obtain an exclusive, royalty bearing, worldwide license to any intellectual property generated by any funded research project. If the Company elects to exercise its right to obtain such a license, the Company will have a specified period of time to negotiate and enter into a mutually agreeable license agreement with Blumberg. This license agreement will include the following pre negotiated upfront, milestone and royalty payments: an upfront payment in the amount of $100,000; up to $8,100,000 upon the achievement of specified development and regulatory milestones; up to $92,500,000 upon the achievement of specified commercialization milestones; and royalties at a low single to mid-single digit rates based upon the proportionate net sales of licensed products from any commercialized combination.

NeuroVive Pharmaceutical AB (“NeuroVive”)

In September 2014, Arbutus Inc. entered into a license agreement with NeuroVive that granted them an exclusive, worldwide, sub-licensable license to develop, manufacture and commercialize, for the treatment of HBV, oral dosage form sanglifehrin based cyclophilin inhibitors (including OCB-030). Under this license agreement, the Company has been granted a non-exclusive, royalty free right and license and right of reference to NeuroVive’s relevant regulatory approvals and filings for the sole purpose of developing, manufacturing and commercializing licensed products for the treatment of HBV. Under this license agreement, the Company has (1) an option to expand its exclusive license to include treatment of viral diseases other than HBV and (2) an option, exercisable upon specified conditions, to expand its exclusive license to include development, manufacture and commercialization of non-oral variations of licensed products for treatment of viral diseases other than HBV. NeuroVive retains all rights with respect to development, manufacture and commercialization of licensed products and non-oral variations of licensed products for all indications (other than HBV) for which the Company has not exercised its option.

In partial consideration for this license, Arbutus Inc. paid NeuroVive a license fee of $1,000,000. As described in note 3 above, Arbutus Inc. became our wholly owned subsidiary by way of a Merger Agreement, which does not trigger any milestone payments. We have conducted significant research and analysis on the NeuroVive Product, OCB-030. Based on this research and analysis, we have decided to discontinue the OCB-030 development program. Otherwise, the license agreement and ongoing relationship with NeuroVive remains in full effect.

Cytos Biotechnology Ltd (“Cytos”)

On December 30, 2014, Arbutus Inc. entered into an exclusive, worldwide, sub-licensable (subject to certain restrictions with respect to licensed viral infections other than hepatitis) license to six different series of compounds. The licensed compounds are Qbeta-derived virus-like particles that encapsulate TLR9, TLR7 or RIG-I agonists and may or may not be conjugated with antigens from the hepatitis virus or other licensed viruses. The Company has an option to expand this license to include additional viral infections other than influenza and Cytos will retain all rights for influenza, all non-viral infections, and all viral infections (other than hepatitis) for which it has not exercised its option.

In partial consideration for this license, the Company is obligated to pay Cytos up to a total of $67,000,000 for each of the six licensed compound series upon the achievement of specified development and regulatory milestones; for hepatitis and each additional licensed viral infection, up to a total of $110,000,000 upon the achievement of specified sales performance milestones; and tiered royalty payments in the high-single to low-double digits, based upon the proportionate net sales of licensed products in any commercialized combination.

Concentrations of Business Risk

12 Months Ended

Dec. 31, 2015

Risks and Uncertainties [Abstract]

Concentrations of business risk

Credit risk

Credit risk is defined by the Company as an unexpected loss in cash and earnings if a collaborative partner is unable to pay its obligations in due time. The Company’s main source of credit risk is related to its accounts receivable balance which principally represents temporary financing provided to collaborative partners in the normal course of operations.

The Company does not currently maintain a provision for bad debts as the majority of accounts receivable are from collaborative partners or government agencies and are considered low risk.

The carrying amount of financial assets represents the maximum credit exposure. The maximum exposure to credit risk at December 31, 2015 was the accounts receivable balance of $1,008,000 (2014 - $1,903,000).

All accounts receivable balances were current as at December 31, 2015 and December 31, 2014.

Significant collaborators and customers risk

We depend on a small number of collaborators and customers for a significant portion of our revenues (see note 4).

Liquidity Risk

Liquidity risk results from the Company’s potential inability to meet its financial liabilities, for example payments to suppliers. The Company ensures sufficient liquidity through the management of net working capital and cash balances.

The Company’s liquidity risk is primarily attributable to its cash and cash equivalents, and short-term investments. The Company limits exposure to liquidity risk on its liquid assets through maintaining its cash and cash equivalent, and short-term investments with high-credit quality financial institutions. Due to the nature of these investments, the funds are available on demand to provide optimal financial flexibility.

The Company believes that its current sources of liquidity are sufficient to cover its likely applicable short term cash obligations. The Company’s financial obligations include accounts payable and accrued liabilities which generally fall due within 45 days. The net liquidity of the Company is considered to be the cash and cash equivalents and short-term investments less accounts payable and accrued liabilities.



	December 31, 2015			December 31, 2014
Cash, cash equivalents and short-term investments	$	181,304		$	112,161
Less: Accounts payable and accrued liabilities	(8,827		)	(9,328		)
	$	172,477		$	102,833

Foreign currency risk

The results of the Company’s operations are subject to foreign currency transaction and translation risk as the Company’s revenues and expenses are denominated in both Canadian and US dollars. The fluctuation of the US dollar in relation to the Canadian dollar will consequently have an impact upon the Company’s reported income or loss and may also affect the value of the Company’s assets, liabilities, and the amount of shareholders’ equity both as recorded in the Company’s financial statements, in the Canadian functional currency, and as reported, for presentation purposes, in the US dollar.

The Company manages its US dollar exchange rate risk by, whenever possible, using cash received from US dollar revenues and financing to pay US dollar expenses. Prior to the financing in October 2013 (note 6(a)), which was denominated in US dollars, the Company’s policy was to convert all but a working capital level of US dollars into Canadian dollars. Given the Company’s increasing level of US dollar expenses, its policy is now to maintain US and Canadian dollar cash and investment and short-term investment balances based on long term forecasts of currency needs thereby creating a natural currency hedge.

The Company has not entered into any agreements or purchased any instruments to hedge possible currency risks. The Company’s exposure to US dollar currency expressed in Canadian dollars was as follows:



(in C$)	December 31, 2015			December 31, 2014
Cash and cash equivalents and short-term investments	$	213,419		$	75,224
Accounts receivable	1,071			1,942
Accrued revenue	178			624
Accounts payable and accrued liabilities	(8,061		)	(4,494		)
	$	206,607		$	73,296

An analysis of the Company’s sensitivity to foreign currency exchange rate movements is not provided in these financial statements as the Company’s US dollar cash holdings and expected US dollar revenues are sufficient to cover US dollar expenses for the foreseeable future.

Interim Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Interim financial data (unaudited)



	2015
	Q1			Q2			Q3			Q4			Total
Revenue	$	4,682		$	3,440		$	4,065		$	12,686		$	24,873
Loss from operations	(18,006		)	(14,420		)	(58,138		)	(11,758		)	(102,322		)
Net loss	$	(11,989	)	$	(14,886	)	$	(28,982	)	$	(5,264	)	$	(61,121	)
Basic and diluted net loss per share	$	(0.40	)	$	(0.27	)	$	(0.57	)	$	(0.10	)	$	(1.34	)



	2014
	Q1			Q2			Q3			Q4			Total
Revenue	$	4,430		$	1,811		$	4,362		$	4,350		$	14,953
Loss from operations	(5,958		)	(9,423		)	(6,844		)	(10,747		)	(33,434		)
Net loss	$	(17,984	)	$	(6,081	)	$	(8,604	)	$	(6,168	)	$	(38,837	)
Basic and diluted net loss per share	$	(0.91	)	$	(0.28	)	$	(0.39	)	$	(0.27	)	$	(1.80	)

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent events	Subsequent events (a) Protiva USA Reorganization Effective January 1, 2016, the Company undertook a corporate reorganization merging Protiva USA into Arbutus Inc., which acquired Protiva USA's assets and assumed Protiva USA's liabilities in exchange for Arbutus Inc. shares. The reorganization did not result in any adverse Canadian and U.S. tax consequences. (b) Monsanto Option Exercise On March 4, 2016, Monsanto exercised its option to acquire 100% of the outstanding shares of Protiva Agricultural Development Company Inc. (PADCo), pursuant under its Option Agreement with the Company. Monsanto will pay the Company $1,000,000 in exercise fee, which the Company will record in the statement of operations and comprehensive loss for the period ended March 31, 2016.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Basis of presentation

Use of estimates

Cash and cash equivalents

Short-term and long-term investments

Fair value of financial instruments

We measure certain financial instruments and other items at fair value.


•	Level 1 inputs are quoted market prices for identical instruments available in active markets.


•	Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets.


•	Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability.

Inventory

Materials purchased for the Company’s own research and development products are not recorded as inventory but are expensed as incurred.

Property and equipment



	Useful life (years)
Laboratory equipment		5
Computer and office equipment	2	—	5
Furniture and fixtures		5

Leasehold improvements are depreciated over their estimated useful lives but in no case longer than the lease term, except where lease renewal is reasonably assured.

Impairment of property and equipment

Goodwill and intangible assets

The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.

Revenue recognition

Leases and lease inducements

All other leases are accounted for as operating leases wherein rental payments are expensed as incurred.

Research and development costs

Income or loss per share

Government grants and refundable investment tax credits

Foreign currency translation and change in reporting currency

Deferred income taxes

Stock-based compensation

The fair value of stock options is measured at the grant date and amortized on a straight-line basis over the vesting period.

Replacement awards

Warrants

Segment information

Recent accounting pronouncements

Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Assets measured at fair value on a recurring basis



	Level 1		Level 2	Level 3		December 31, 2015
Assets
Cash and cash equivalents	$	166,779	—	—		$	166,779
Guaranteed investment certificate	14,525		—	—		14,525
Term deposit	10,070		—	—		10,070
Total	$	191,374	—	—		$	191,374
Liabilities
Warrants	—		—	$	883	$	883
Contingent consideration	—		—	7,497		7,497
Financial instrument	—		—	—		—
Total	—		—	$	8,380	$	8,380



	Level 1		Level 2	Level 3		December 31, 2014
Assets
Cash and cash equivalents	$	72,187	—	—		$	72,187
Guaranteed investment certificates	39,974		—	—		39,974
Total	$	112,161	—	—		$	112,161
Liabilities
Warrants	—		—	$	5,099	$	5,099
Financial instrument	—		—	—		—
Total	—		—	$	5,099	$	5,099

Changes in fair value of warrants

The following table presents the changes in fair value of the Company’s warrants:



	Liability at beginning of the period		Warrants issued in the period		Fair value of warrants exercised in the period			Increase (decrease) in fair value of warrants			Foreign exchange loss			Liability at end of the period
Year ended December 31, 2013	$	4,015	$	—	$	(1,854	)	$	3,530		$	(312	)	$	5,379
Year ended December 31, 2014	$	5,379	—		$	(10,208	)	$	10,383		$	(455	)	$	5,099
Year ended December 31, 2015	$	5,099	—		$	(334	)	$	(3,341	)	$	(541	)	$	883

Changes in fair value of contingent consideration

The following table presents the changes in fair value of the Company’s contingent consideration:



	Liability at beginning of the period ⁽¹⁾		Increase in fair value of contingent consideration		Liability at end of the period
Year ended December 31, 2015	$	6,727	$	770	$	7,497

(1) As at acquisition date of March 4, 2015 - see note 3 below.

Property and equipment estimated useful lives

The Company records depreciation using the straight-line method over the estimated useful lives of the capital assets as follows:



	Useful life (years)
Laboratory equipment		5
Computer and office equipment	2	—	5
Furniture and fixtures		5

Schedule of basic and diluted net income (loss) per common share

The following table sets out the computation of basic and diluted net income (loss) per common share:



	For the year ended December 31
	2015			2014			2013
Numerator:
Net loss	$	(61,121	)	$	(38,837	)	$	(14,063	)
Denominator:
Weighted average number of common shares	45,462,324			21,603,136			15,302,680
Basic income (loss) per common share	$	(1.34	)	$	(1.80	)	$	(0.92	)
Diluted income (loss) per common share	$	(1.34	)	$	(1.80	)	$	(0.92	)

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) (Tables)

12 Months Ended

Dec. 31, 2015

Business Combinations [Abstract]

Schedule of finalized acquisition purchase price allocation

The following table summarizes the Company’s finalized purchase price allocation as at December 31, 2015:



Consideration paid:
Common shares issued without subjects	$	371,553
Common shares issued subject to repurchase provision	9,262
Common shares issuable for Arbutus Inc. stock options	1,127
	$	381,942

Identifiable assets acquired and liabilities assumed:
Cash	$	324
Prepaid expenses and other assets	116
Accounts receivable	8
Property and equipment	147
Acquired intangible assets	391,649
Goodwill	162,514
Accounts payable and accrued liabilities	(3,580		)
Other non-current liabilities (note 9)	(6,727		)
Deferred income tax liability	(162,509		)
Total purchase price allocation	$	381,942

Schedule of identifiable intangible assets acquired

The identifiable intangible assets acquired consist of in-process research and development (IPR&D) HBV assets, as summarized in the table below:



IPR&D – Cyclophilins	$	39,007
IPR&D – Immune Modulators	183,103
IPR&D – Antigen Inhibitors	36,437
IPR&D – cccDNA Sterilizers	133,102
Total IPR&D	$	391,649

Summary of revisions and adjustments to business acquisition purchase price allocation

The following table presents a summary of revisions and adjustments made to the preliminary estimates as previously disclosed to the finalized purchase price allocation:



	Preliminary Amounts Recognized as of Acquisition Date ⁽¹⁾			Measurement Period Adjustments⁽²⁾			Amounts Recognized as of Acquisition Date (as adjusted)
Purchase Price	$	381,942		$	—		$	381,942

Identifiable assets acquired and liabilities assumed:
Cash	$	324		$	—		$	324
Prepaid expenses and other assets	127			(11		)	116
Accounts receivable	8			—			8
Property and equipment	147			—			147
Acquired intangible assets	389,652			1,997			391,649
Goodwill	155,865			6,649			162,514
Accounts payable and accrued liabilities	(3,580		)	—			(3,580		)
Other non-current liabilities (note 8)	(4,736		)	(1,991		)	(6,727		)
Deferred income tax liability	(155,865		)	(6,644		)	(162,509		)
Total purchase price allocation	$	381,942		$	—		$	381,942


1.	The preliminary purchase price as of the acquisition date of March 4, 2015 as previously disclosed in the notes to consolidated financial statements included in the Company's Quarterly Report on Form 10-Q for the period ended March 31, 2015.


2.	The measurement period is from the acquisition date of March 4, 2015 to the date the Company finalized the purchase price allocation on December 31, 2015.

Business acquisition, pro forma financial information

The pro forma financial information presented includes acquisition costs, amortization charges for acquired tangible assets, impairment charge on acquired intangible assets (as described in note 3b below), but does not include amortization charges for acquired intangible assets as these assets have not yet been put in use.



	Year ended
	December 31,
	2015			2014
Pro forma information
Gross Revenue	$	24,873		$	14,953
Loss from operations	(109,387		)	(51,088		)
Net loss	(67,416		)	(56,491		)
Basic and diluted loss per share	$	(1.38	)	$	(1.24	)

Schedule of intangible assets net of impairment

The following table summarizes the carrying values, net of impairment of the intangible assets as at December 31, 2015:



IPR&D – Cyclophilins	$	—
IPR&D – Immune Modulators	183,103
IPR&D – Antigen Inhibitors	36,437
IPR&D – cccDNA Sterilizers	133,102
Total IPR&D	$	352,642

Collaborations, Contracts and Licensing Agreements (Tables)

12 Months Ended

Dec. 31, 2015

Deferred Revenue Disclosure [Abstract]

Schedule of revenue recognized under collaborations, contracts and licensing agreements

The following tables set forth revenue recognized under collaborations, contracts and licensing agreements:



	Year ended December 31
	2015		2014		2013
Collaborations and contracts
DoD (a)	$	6,764	$	8,407	$	9,806
Monsanto (b)	4,725		1,080		—
BMS (d)	—		1,741		526
Dicerna (e)	1,820		510		—
Other RNAi collaborators (g)	—		—		93
Total research and development collaborations and contracts	13,309		11,738		10,425
Licensing fees, milestone and royalty payments
Monsanto licensing fees and milestone payments (b)	10,256		2,744		—
Alnylam and Acuitas licensing fees and milestone payments (c)	15		150		5,000
Dicerna licensing fee (e)	1,053		131		—
Spectrum royalty payments (f)	240		190		40
Total licensing fees, milestone and royalty payments	11,564		3,215		5,040
Total revenue	$	24,873	$	14,953	$	15,465

Schedule of deferred collaborations and contracts revenue

The following table sets forth deferred collaborations and contracts revenue:



	December 31, 2015		December 31, 2014
DoD (a)	$	15	$	313
Monsanto current portion (b)	—		4,245
Dicerna current portion (e)	853		1,221
Deferred revenue, current portion	868		5,779
Monsanto long-term portion (b)	—		8,666
Dicerna long-term portion (e)	213		1,271
Total deferred revenue	$	1,081	$	15,716

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Schedule of property and equipment



December 31, 2015	Cost		Accumulated depreciation			Net book value
Lab equipment	$	5,910	$	(3,748	)	$	2,162
Leasehold improvements	4,681		(4,189		)	492
Computer hardware and software	2,014		(1,487		)	527
Furniture and fixtures	307		(305		)	2
	$	12,912	$	(9,729	)	$	3,183



December 31, 2014	Cost		Accumulated depreciation			Net book value
Lab equipment	$	5,021	$	(4,451	)	$	570
Leasehold improvements	5,281		(4,796		)	485
Computer hardware and software	2,293		(1,588		)	705
Furniture and fixtures	364		(364		)	—
	$	12,959	$	(11,199	)	$	1,760

Share Capital (Tables)

12 Months Ended

Dec. 31, 2015

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of warrant activity

The following table summarizes the Company’s warrant activity for the years ended December 31, 2015 and 2014:



	Common shares purchasable upon exercise of warrants		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Range of exercise prices (C$)				Range of exercise prices (US$)				Weighted average remaining contractual life (years)	Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2013	1,014,728		$	2.90	$	2.72	$2.60	—	$	3.35	$2.44	—	$	3.15	2.7	$	5,635	$	5,298
Exercised	(616,478	)	3.09		2.80		2.60	—	3.35		2.35	—	3.03
Balance, December 31, 2014	398,250		2.95		2.67		2.60	—	3.35		2.35	—	3.03		1.8	5,902		5,343
Exercised	(18,750	)	2.88		2.25		2.60	—	3.35		2.03	—	2.62
Balance, December 31, 2015	379,500		$	2.95	$	2.13	$2.60	—	$	3.35	$2.03	—	$	2.62	0.8	$	1,217	$	879

Schedule of weighted average Black-Scholes option-pricing assumptions and resultant fair values

The weighted average Black-Scholes option-pricing assumptions and the resultant fair values are as follows for warrants outstanding at December 31, 2015 and 2014 are as follows:



	As at December 31
	2015			2014
Dividend yield	—		%	—		%
Expected volatility	49.07		%	85.22		%
Risk-free interest rate	0.48		%	1.00		%
Expected average term (years)	0.6 years			0.5 years
Fair value of warrants outstanding	$	2.33		$	12.80
Aggregate fair value of warrants outstanding	$	883		$	5,099
Number of warrants outstanding	379,500			398,250

Schedule of stock option activity for the Arbutus Plans

Stock option activity for the Arbutus Plans



	Number of optioned common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2012	1,648,846		$	4.54	$	4.54	$	2,300	$	2,301
Options granted	270,250		7.52		7.30
Options exercised	(124,246	)	3.22		3.13		551		535
Options forfeited, canceled or expired	(64,085	)	21.87		21.23
Balance, December 31, 2013	1,730,765		4.45		4.32		7,030		6,826
Options granted	431,125		13.63		12.34
Options exercised	(622,752	)	4.62		4.18		7,650		6,926
Options forfeited, canceled or expired	(9,000	)	8.20		7.42
Balance, December 31, 2014	1,530,138		6.95		6.29		16,573		15,004
Options granted	1,309,625		N/A		16.57
Options exercised	(398,293	)	5.03		3.93		6,887		5,386
Options forfeited, canceled or expired	(151,207	)	19.29		15.09
Balance, December 31, 2015	2,290,263		$	15.53	$	11.22	$	1,376	$	994

Summary of stock options outstanding by exercise price range

The following table summarizes information pertaining to stock options outstanding at December 31, 2015 under the Arbutus Plans:



			Options outstanding December 31, 2015				Options exercisable December 31, 2015
Range of Exercise prices (US$)			Number of options outstanding	Weighted average remaining contractual life (years)	Weighted average exercise price (US$)		Number of options exercisable	Weighted average exercise price (US$)
$1.08	to	$1.37	102,800	4.9	$	1.24	102,800	$	1.24
$1.52	to	$1.88	120,475	5.8	1.66		120,475	1.66
$2.17	to	$2.78	83,000	2.9	2.56		83,000	2.56
$3.24	to	$4.70	288,960	5.4	3.84		268,900	3.83
$5.10	to	$7.50	261,923	7.7	6.33		175,112	6.12
$8.38	to	$10.04	176,813	8.7	9.35		99,189	9.24
$10.69	to	$13.39	129,417	8.2	11.93		79,252	11.90
$13.40	to	$17.57	1,126,875	9.2	17.02		10,002	17.57
$1.08	to	$17.57	2,290,263	7.9	$	11.22	938,730	$	4.98

Schedule of non-vested stock option activity

A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2015 is as follows:



	Number of optioned common shares		Weighted average fair value (C$)		Weighted average fair value (US$)
Non-vested at December 31, 2014	441,230		$	9.30	$	8.42
Options granted	1,309,625		15.20		11.89
Options vested	(250,461	)	8.77		6.86
Non-vested options forfeited	(148,853	)	14.27		11.16
Non-vested at December 31, 2015	1,351,541		$	15.69	$	11.34

Schedule of weighted average option pricing assumptions and the resultant fair values

The weighted average option pricing assumptions and the resultant fair values are as follows:



	Year ended December 31
	2015		2014		2013

Dividend yield	—	%	—	%	—	%
Expected volatility	76.88	%	101.08	%	111.61	%
Risk-free interest rate	1.10	%	2.25	%	2.39	%
Expected average option term	7.5 years		8.8 years		9.6 years

Schedule of allocation of stock-based compensation

The total stock-based compensation has been recorded in the consolidated statement of operations and comprehensive income (loss) as follows:



	Year ended December 31
	2015		2014		2013
Research, development, collaborations and contracts expenses	$	7,868	$	2,343	$	622
General and administrative expenses	14,225		940		281
Total	$	22,093	$	3,283	$	903

Protiva Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of option activity

The following table sets forth outstanding options under the Protiva Option Plan:



	Number of Protiva Options		Equivalent number of Company common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)
Balance, December 31, 2012	475,885		321,299		$	0.30	0.30
Options exercised	(2,000	)	(1,350	)	0.30		0.29
Options forfeited, canceled or expired	(1,000	)	(675	)	0.30		0.29
Balance, December 31, 2013	472,885		319,274		0.30		0.29
Options exercised	(38,145	)	(25,754	)	0.30		0.27
Options forfeited, canceled or expired	(1,000	)	(675	)	0.30		0.27
Balance, December 31, 2014	433,740		292,845		0.30		0.27
Options exercised	(358,675	)	(242,164	)	0.30		0.23
Options forfeited, canceled or expired	(8,065	)	(5,445	)	0.30		0.23
Balance, December 31, 2015	67,000		45,236		$	0.30	$	0.22

OnCore Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of non-vested stock option activity

A summary of the OnCore Option Plan's non-vested stock option activity and related information for the period from acquisition to December 31, 2015 is as follows:



	Number of OnCore Options		Equivalent number of Company common shares		Weighted average fair value (US$)
Non-vested at March 4, 2015	128,510		129,417		$	16.42
Options vested	(32,128	)	(32,354	)	16.42
Non-vested options forfeited	—		—		N/A
Non-vested at December 31, 2015	96,382		97,063		$	16.42

Schedule of option activity

The following table sets forth outstanding options under the OnCore Option Plan:



	Number of OnCore Options	Equivalent number of Company common shares	Weighted average exercise price (US$)
Balance, March 4, 2015	183,040	184,332	$	0.57
Options exercised	—	—	N/A
Options forfeited, canceled or expired	—	—	N/A
Balance, December 31, 2015	183,040	184,332	$	0.57

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of effective income tax rate reconciliation



	Year ended December 31,
	2015			2014			2013
Computed taxes (recoveries) at Canadian federal and provincial tax rates	$	(20,100	)	$	(10,097	)	$	(3,486	)
Differences due to change in enacted tax rates	—			—			(9		)
Permanent and other differences	8,113			3,498			1,088
Change in valuation allowance - other	3,676			6,599			2,407
Difference due to income taxed at foreign rates	(7,874		)	—			—
Deferred income tax recovery	$	(16,185	)	$	—		$	—

Schedule of components of deferred tax assets

Significant components of the Company’s deferred tax assets are shown below:



	As at December 31,
	2015			2014
Deferred tax assets:
Non-capital loss carryforwards	$	13,932		$	6,578
Research and development deductions	13,474			14,006
Book amortization in excess of tax	2,142			2,745
Share issue costs	777			1,195
Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes	281			4,086
Tax value in excess of accounting value in lease inducements	77			65
Federal investment tax credits	6,303			5,821
Provincial investment tax credits	3,879			3,322
In-process research and development	(146,324		)	—
Upfront license fees	629			—
Total deferred tax assets	(104,830		)	37,818
Valuation allowance	(41,494		)	(37,818		)
Net deferred tax assets	$	(146,324	)	$	—

Concentrations of Business Risk (Tables)

12 Months Ended

Dec. 31, 2015

Risks and Uncertainties [Abstract]

Net liquidity

The net liquidity of the Company is considered to be the cash and cash equivalents and short-term investments less accounts payable and accrued liabilities.



	December 31, 2015			December 31, 2014
Cash, cash equivalents and short-term investments	$	181,304		$	112,161
Less: Accounts payable and accrued liabilities	(8,827		)	(9,328		)
	$	172,477		$	102,833

Schedule of exposure to US dollar currency expressed in Canadian dollars

The Company’s exposure to US dollar currency expressed in Canadian dollars was as follows:



(in C$)	December 31, 2015			December 31, 2014
Cash and cash equivalents and short-term investments	$	213,419		$	75,224
Accounts receivable	1,071			1,942
Accrued revenue	178			624
Accounts payable and accrued liabilities	(8,061		)	(4,494		)
	$	206,607		$	73,296

Interim Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Schedule of interim financial data (unaudited)



	2015
	Q1			Q2			Q3			Q4			Total
Revenue	$	4,682		$	3,440		$	4,065		$	12,686		$	24,873
Loss from operations	(18,006		)	(14,420		)	(58,138		)	(11,758		)	(102,322		)
Net loss	$	(11,989	)	$	(14,886	)	$	(28,982	)	$	(5,264	)	$	(61,121	)
Basic and diluted net loss per share	$	(0.40	)	$	(0.27	)	$	(0.57	)	$	(0.10	)	$	(1.34	)



	2014
	Q1			Q2			Q3			Q4			Total
Revenue	$	4,430		$	1,811		$	4,362		$	4,350		$	14,953
Loss from operations	(5,958		)	(9,423		)	(6,844		)	(10,747		)	(33,434		)
Net loss	$	(17,984	)	$	(6,081	)	$	(8,604	)	$	(6,168	)	$	(38,837	)
Basic and diluted net loss per share	$	(0.91	)	$	(0.28	)	$	(0.39	)	$	(0.27	)	$	(1.80	)

Significant Accounting Policies - Narrative (Details) $ in Thousands	10 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($) subsidiary	Dec. 31, 2015 USD ($) subsidiary shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($) shares	Mar. 04, 2015 USD ($)
Accounting Policies [Abstract]
Wholly-owned subsidiaries \| subsidiary	4	4
Fair value of contingent consideration	$ 7,497	$ 7,497	$ 0		$ 6,727
Change in fair value of contingent consideration	$ 770	$ 770	$ 0	$ 0
Anti-dilutive common shares excluded from calculation of income per common share \| shares		2,899,331	2,221,233	3,064,767

Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Mar. 04, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 166,779		$ 72,187
Guaranteed investment certificate	14,525		39,974
Term deposit	10,070		0
Total Assets	191,374		112,161
Liabilities
Warrants	883		5,099	$ 5,379	$ 4,015
Contingent consideration	7,497	$ 6,727	0
Financial instrument	0		0
Total Liabilities	8,380		5,099
Fair Value, Inputs, Level 1
Assets
Cash and cash equivalents	166,779		72,187
Guaranteed investment certificate	14,525		39,974
Term deposit	10,070
Total Assets	191,374		112,161
Fair Value, Inputs, Level 3
Liabilities
Warrants	883		5,099
Contingent consideration	7,497
Financial instrument	0		0
Total Liabilities	$ 8,380		$ 5,099

Significant Accounting Policies - Changes in Fair Value of the Company's Warrants (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]
Liability at beginning of the period	$ 5,099	$ 5,379	$ 4,015
Warrants issued in the period	0	0	0
Fair value of warrants exercised in the period	(334)	(10,208)	(1,854)
Increase (decrease) in fair value of warrants	(3,341)	10,383	3,530
Foreign exchange loss	(541)	(455)	(312)
Liability at end of the period	$ 883	$ 5,099	$ 5,379

Significant Accounting Policies - Changes in Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands	10 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration Fair Value, Liability [Roll Forward]
Liability at beginning of the period	$ 6,727	$ 0
Increase in fair value of contingent consideration	770	770	$ 0	$ 0
Liability at end of the period	$ 7,497	$ 7,497	$ 0

Significant Accounting Policies - Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2015
Laboratory equipment
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Computer and office equipment \| Minimum
Property, Plant and Equipment [Line Items]
Useful lives	2 years
Computer and office equipment \| Maximum
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful lives	5 years

Significant Accounting Policies - Computation of Basic and Diluted Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Net loss	$ (5,264)	$ (28,982)	$ (14,886)	$ (11,989)	$ (6,168)	$ (8,604)	$ (6,081)	$ (17,984)	$ (61,121)	$ (38,837)	$ (14,063)
Weighted average number of common shares									45,462,324	21,603,136	15,302,680
Basic income (loss) per common share (in USD per share)									$ (1.34)	$ (1.80)	$ (0.92)
Diluted income (loss) per common share (in USD per share)									$ (1.34)	$ (1.80)	$ (0.92)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) - Narrative (Details)						2 Months Ended	3 Months Ended	10 Months Ended		12 Months Ended
	May. 31, 2016 shares	Feb. 29, 2016 shares	Nov. 30, 2015 shares	Oct. 28, 2015 USD ($)	Mar. 04, 2015 USD ($) shares	Dec. 31, 2015 USD ($) shares	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2015 USD ($) reporting_unit shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Mar. 03, 2015 $ / shares	Jan. 11, 2015	Dec. 31, 2012 USD ($)
Business Acquisition [Line Items]
Acquisition costs										$ 9,656,000	$ 462,000	$ 0
Risk-free interest rate										0.48%	1.00%
Expected volatility										49.07%	85.22%
Dividend yield										0.00%	0.00%
Expected average term (years)										7 months 6 days	6 months
Acceleration of compensation expense							$ 1,900,000
Impairment charge										$ 39,007,000	$ 0	0
Income tax benefit related to impairment charge										16,185,000	0	0
Goodwill						$ 162,514,000		$ 162,514,000	$ 162,514,000	$ 162,514,000	0
Number of reporting units \| reporting_unit										1
Market capitalization						242,844,000		242,844,000	242,844,000	$ 242,844,000
Net loss										(67,416,000)	(56,491,000)
Company's carrying value						547,679,000		547,679,000	547,679,000	547,679,000	88,035,000	$ 59,194,000			$ 40,919,000
Subsequent event
Business Acquisition [Line Items]
Stock repurchase rights expiration rate (in shares) \| shares		302,120
Arbutus Inc.
Business Acquisition [Line Items]
Business acquisition, percentage of outstanding shares acquired														100.00%
Acquisition costs										9,656,000	$ 462,000
Fair value of consideration issued					$ 381,942,000
Common shares issued for acquisition \| shares					23,973,315
Business acquisition, fair value amount attributed as pre-combination service and included as part of acquisition consideration					$ 9,262,000
Business acquisition, post-combination attribution recognized as compensation expense					$ 56,934,000
Stock-based compensation expense									16,687,000
Stock repurchase rights expiration rate (in shares) \| shares			302,120
Period of estimated cash flows					20 years
Discount rate					13.70%
Intangible assets acquired, fair value					$ 391,649,000
Measurement period adjustments, intangibles								1,997,000
Measurement period adjustments, goodwill								6,649,000
Goodwill					$ 155,865,000	162,514,000		162,514,000	162,514,000	162,514,000
Net loss									13,658,000
Arbutus Inc. \| Scenario, forecast
Business Acquisition [Line Items]
Stock repurchase rights expiration rate (in shares) \| shares	503,552
Arbutus Inc. \| Common shares issued without subjects
Business Acquisition [Line Items]
Fair value of consideration issued						371,553,000		371,553,000	371,553,000	371,553,000
Common shares issued for acquisition \| shares					20,347,906
Business acquisition, share price (in USD per share) \| $ / shares													$ 18.26
Arbutus Inc. \| Common shares issued subject to repurchase provision
Business Acquisition [Line Items]
Fair value of consideration issued					$ 66,196,000	$ 9,262,000		$ 9,262,000	9,262,000	$ 9,262,000
Common shares issued for acquisition \| shares					3,625,412
Risk-free interest rate					0.74%
Expected volatility					81.00%
Dividend yield					0.00%
Expected average term (years)					4 years
Shares issued and outstanding (in shares) \| shares					3,625,412
Arbutus Inc. \| Abutus stock options
Business Acquisition [Line Items]
Fair value of consideration issued					$ 3,287,000
Risk-free interest rate					0.97%
Expected volatility					78.00%
Dividend yield					0.00%
Expected average term (years)					8 years
Business acquisition, fair value amount attributed as pre-combination service and included as part of acquisition consideration					$ 1,127,000
Business acquisition, post-combination attribution recognized as compensation expense					2,160,000
Stock-based compensation expense									$ 463,000
Shares reserved for future exercise \| shares						184,332		184,332	184,332	184,332
Cyclophilin \| Arbutus Inc.
Business Acquisition [Line Items]
Intangible assets acquired, fair value					$ 39,007,000	$ 39,007,000	$ 37,990,000	$ 39,007,000	$ 39,007,000	$ 39,007,000
Measurement period adjustments, intangibles						1,017,000
Impairment charge				$ 37,990,000
Income tax benefit related to impairment charge				$ 15,196,000		$ 989,000
Other IPR&D
Business Acquisition [Line Items]
Impairment charge										0
Goodwill
Business Acquisition [Line Items]
Impairment charge										$ 0

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Mar. 04, 2015	Dec. 31, 2014
Identifiable assets acquired and liabilities assumed:
Goodwill	$ 162,514		$ 0
Arbutus Inc.
Business Acquisition [Line Items]
Consideration paid		$ 381,942
Identifiable assets acquired and liabilities assumed:
Cash	324	324
Prepaid expenses and other assets	116	127
Accounts receivable	8	8
Property and equipment	147	147
Acquired intangible assets	391,649	389,652
Goodwill	162,514	155,865
Accounts payable and accrued liabilities	(3,580)	(3,580)
Other non-current liabilities	(6,727)	(4,736)
Deferred income tax liability	(162,509)	(155,865)
Total purchase price allocation	381,942	381,942
Common shares issued without subjects \| Arbutus Inc.
Business Acquisition [Line Items]
Consideration paid	371,553
Common shares issued subject to repurchase provision \| Arbutus Inc.
Business Acquisition [Line Items]
Consideration paid	9,262	$ 66,196
Common share issuable for Arbutus Inc. stock options \| Arbutus Inc.
Business Acquisition [Line Items]
Consideration paid	$ 1,127

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) - Summary of Acquired Identifiable Intangible Assets (Details) - Arbutus Inc. - USD ($) $ in Thousands	Dec. 31, 2015	Sep. 30, 2015	Mar. 04, 2015
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets acquired			$ 391,649
IPR&D Cyclophilins
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets acquired	$ 39,007	$ 37,990	39,007
IPR&D Immune Modulators
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets acquired			183,103
IPR&D Antigen Inhibitors
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets acquired			36,437
IPR&D cccDNA Sterilizers
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets acquired			$ 133,102

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) - Reconciliation of Preliminary to Final Purchase Price Allocation (Details) - USD ($) $ in Thousands			10 Months Ended
	Dec. 31, 2015	Mar. 04, 2015	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 162,514		$ 162,514	$ 162,514	$ 0
Arbutus Inc.
Business Acquisition [Line Items]
Purchase Price	381,942	$ 381,942		381,942
Cash	324	324	324	324
Measurement Period Adjustments, Cash			0
Prepaid expenses and other assets	116	127	116	116
Measurement Period Adjustments, Prepaid expenses and other assets			(11)
Accounts receivable	8	8	8	8
Measurement Period Adjustments, Accounts receivable			0
Property and equipment	147	147	147	147
Measurement Period Adjustments, Property and equipment			0
Acquired intangible assets	391,649	389,652	391,649	391,649
Measurement Period Adjustments, Acquired intangible assets			1,997
Goodwill	162,514	155,865	162,514	162,514
Measurement Period Adjustments, Goodwill			6,649
Accounts payable and accrued liabilities	(3,580)	(3,580)	(3,580)	(3,580)
Measurement Period Adjustments, Accounts payable and accrued liabilities			0
Other non-current liabilities	(6,727)	(4,736)	(6,727)	(6,727)
Measurement Period Adjustments, Other non-current liabilities			(1,991)
Deferred income tax liability	(162,509)	(155,865)	(162,509)	(162,509)
Measurement Period Adjustments, Deferred income tax liability			(6,644)
Total purchase price allocation	$ 381,942	$ 381,942	381,942	$ 381,942
Measurement Period Adjustments, Total			$ 0

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Pro forma information
Gross Revenue	$ 24,873	$ 14,953
Loss from operations	(109,387)	(51,088)
Net loss	$ (67,416)	$ (56,491)
Basic and diluted loss per share (in USD per share)	$ (1.38)	$ (1.24)

Merger with Arbutus Biopharma Inc. (formerly OnCore BioPharma, Inc.) - Carrying Value of Intangible Assets After Impairment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets, carrying value after impairments	$ 352,642	$ 0
Arbutus Inc.
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets, carrying value after impairments	352,642
Arbutus Inc. \| IPR&D Cyclophilins
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets, carrying value after impairments	0
Arbutus Inc. \| IPR&D Immune Modulators
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets, carrying value after impairments	183,103
Arbutus Inc. \| IPR&D Antigen Inhibitors
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets, carrying value after impairments	36,437
Arbutus Inc. \| IPR&D cccDNA Sterilizers
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets, carrying value after impairments	$ 133,102

Collaborations, Contracts and Licensing Agreements (Details)							1 Months Ended				3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Nov. 16, 2014 USD ($)	Jan. 13, 2014	Jan. 13, 2014 USD ($)	Jun. 21, 2013 USD ($)	May. 10, 2010 USD ($)	May. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Nov. 30, 2013 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Mar. 09, 2016 USD ($)	Apr. 22, 2014 USD ($)	May. 08, 2013 USD ($)	Jul. 14, 2010 USD ($)	May. 06, 2006 chemotherapy_products
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue											$ 12,686,000	$ 4,065,000	$ 3,440,000	$ 4,682,000	$ 4,350,000	$ 4,362,000	$ 1,811,000	$ 4,430,000	$ 24,873,000	$ 14,953,000	$ 15,465,000
Licensing fees, milestone and royalty payments																			11,564,000	3,215,000	5,040,000
Deferred revenue	$ 1,081,000										1,081,000				15,716,000				1,081,000	15,716,000
Number of chemotherapy products with worldwide licenses \| chemotherapy_products																											3
Contracts revenue																			13,309,000	11,738,000	10,425,000
DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																										$ 34,700,000
Optional exercised contractual option, amount															$ 7,000,000					7,000,000
Contracts revenue																			6,764,000	8,407,000	9,806,000
Monsanto
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Approximate option period			4 years
Maximum potential transaction value				$ 86,200,000			$ 2,000,000
Option period extension							5 months
Payments from inception of contract																			19,300,000
Revenue																			14,981,000
Licensing fees, milestone and royalty payments																			10,256,000	2,744,000	0
Contracts revenue																			4,725,000	1,080,000	0
BMS
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue						$ 3,000,000
Length of agreement with Bristol-Myers Squibb						4 years
Contracts revenue																			0	1,741,000	526,000
Dicerna
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Licensing fees, milestone and royalty payments																			1,053,000	131,000	0
Deferred revenue		$ 2,500,000
Milestone payment		$ 22,000,000
Performance period to recognize revenue	28 months
Contracts revenue																			1,820,000	510,000	0
Talon Therapeutics
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																						$ 18,000,000
Contract extension \| Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																										$ 140,000,000
Alnylam License Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Licensing fees, milestone and royalty payments								$ 150,000	$ 5,000,000	$ 375,000
Marqibo Commercial Sales
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Contracts revenue																						$ 1,000,000
Marqibo
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty revenue																			240,000	190,000	$ 40,000
Accrued royalties	$ 6,000										$ 6,000								6,000
Increase to support development plans \| DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																									$ 6,970,000
Increased funding for stage one \| DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																								$ 2,100,000
Stage one \| DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																								$ 43,819,000
PADCo.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Equity income (loss)																			$ 0	$ 0
Alnylam and Ascletis Pharmaceuticals
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Licensing fees, milestone and royalty payments					$ 5,000,000
Subsequent event \| PADCo. \| Monsanto
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Optional exercised contractual option, amount																							$ 1,000,000
Business acquisition, percentage of outstanding shares acquired																							100.00%

Collaborations, Contracts and Licensing Agreements - Revenue Recognized Under Collaborations, Contracts and Licensing Agreements (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborations and contracts
Contracts revenue									$ 13,309	$ 11,738	$ 10,425
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments									11,564	3,215	5,040
Total revenue	$ 12,686	$ 4,065	$ 3,440	$ 4,682	$ 4,350	$ 4,362	$ 1,811	$ 4,430	24,873	14,953	15,465
DoD
Collaborations and contracts
Contracts revenue									6,764	8,407	9,806
Monsanto
Collaborations and contracts
Contracts revenue									4,725	1,080	0
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments									10,256	2,744	0
Total revenue									14,981
BMS
Collaborations and contracts
Contracts revenue									0	1,741	526
Alnylam License Agreement
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments									15	150	5,000
Dicerna
Collaborations and contracts
Contracts revenue									1,820	510	0
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments									1,053	131	0
Other RNAi Collaborators
Collaborations and contracts
Contracts revenue									0	0	93
Spectrum
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments									$ 240	$ 190	$ 40

Collaborations, Contracts and Licensing Agreements - Deferred Collaborations and Contracts Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Nov. 16, 2014	May. 10, 2010
Deferred Revenue Arrangement [Line Items]
Deferred revenue current portion	$ 868	$ 5,779
Deferred revenue long-term portion	213	9,937
Total deferred revenue	1,081	15,716
DoD
Deferred Revenue Arrangement [Line Items]
Deferred revenue current portion	15	313
Monsanto
Deferred Revenue Arrangement [Line Items]
Deferred revenue current portion	0	4,245
Deferred revenue long-term portion	0	8,666
BMS
Deferred Revenue Arrangement [Line Items]
Total deferred revenue				$ 3,000
Dicerna
Deferred Revenue Arrangement [Line Items]
Deferred revenue current portion	853	1,221
Deferred revenue long-term portion	$ 213	$ 1,271
Total deferred revenue			$ 2,500

Property and Equipment - Property and Equipment Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Cost	$ 12,912	$ 12,959
Accumulated depreciation	(9,729)	(11,199)
Net book value	3,183	1,760
Lab equipment
Property, Plant and Equipment [Line Items]
Cost	5,910	5,021
Accumulated depreciation	(3,748)	(4,451)
Net book value	2,162	570
Leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	4,681	5,281
Accumulated depreciation	(4,189)	(4,796)
Net book value	492	485
Computer hardware and software
Property, Plant and Equipment [Line Items]
Cost	2,014	2,293
Accumulated depreciation	(1,487)	(1,588)
Net book value	527	705
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Cost	307	364
Accumulated depreciation	(305)	(364)
Net book value	$ 2	$ 0

Share Capital (Details) CAD / shares in Units, $ / shares in Units, CAD in Thousands									1 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($) compensation_plan $ / shares shares	Mar. 25, 2015 USD ($) $ / shares shares	Mar. 04, 2015 USD ($) shares	Mar. 26, 2014 USD ($) $ / shares shares	Nov. 02, 2013 USD ($) $ / shares shares	Oct. 22, 2013 $ / shares shares	Jun. 22, 2011	May. 30, 2008 CAD / shares shares	Oct. 22, 2013 USD ($) $ / shares	Dec. 31, 2015 USD ($) compensation_plan $ / shares shares	Dec. 31, 2015 USD ($) compensation_plan $ / shares shares	Dec. 31, 2015 CAD shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2014 CAD shares	Dec. 31, 2013 USD ($) executive_officers shares	Dec. 31, 2013 CAD shares	Dec. 31, 2015 CAD / shares	Jul. 09, 2015 shares	May. 08, 2014 shares	Dec. 31, 2012 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during underwritten public offering (in shares)		7,500,000		2,125,000	562,500	3,750,000
Stock price at public offering (in USD per share) \| $ / shares		$ 20.25		$ 28.50	$ 8.00	$ 8.00			$ 8.00
Number of additional shares authorized (in Shares)				318,750
Gross proceeds from issuance of stock \| $		$ 151,875,000		$ 60,562,000	$ 34,500,000				$ 30,000,000		$ 142,177,000		$ 56,477,000		$ 32,038,000
Period for option to purchase additional shares		30 days		30 days
Payments of stock issuance costs, including commissions and professional fees \| $		$ 9,700,000		$ 4,085,000	2,462,000
Proceeds from issuance of common stock, net \| $		$ 142,177,000		56,477,000	$ 32,038,000
Warrants exercised (in shares)											18,750	18,750	610,478	610,478
Proceeds from warrant exercises \| $											$ 42,000		$ 1,583,000		$ 289,000
Common shares issued from warrants exercise													5,285	5,285
Number of share-based compensation plans \| compensation_plan	6									6	6
Options granted (in shares)		1,125,000									1,309,625	1,309,625
Number of executive officers granted options with new appointments \| executive_officers															2
Number of stock-based compensation awards approved to be issued	3,135,980									3,135,980	3,135,980							3,500,000	800,000
Options exercisable (in shares)	938,730									938,730	938,730		1,088,908		1,377,091
Weighted average remaining contractual life of exercisable options											6 years 1 month 6 days	6 years 1 month 6 days
Aggregate intrinsic value of in-the-money options exercisable \| $	$ 994,000									$ 994,000	$ 994,000
Weighted average remaining contractual life for options expected to vest											9 years 1 month 6 days	9 years 1 month 6 days
Average exercise price for options expected to vest \| (per share)	$ 15.54									$ 15.54	$ 15.54						CAD 21.51
Aggregate intrinsic value of option expected to vest \| $	$ 10,000									$ 10,000	$ 10,000		$ 2,626,000		$ 943,000
Total fair value of options that vested during period \| $											$ 1,718,000		$ 2,505,000		$ 955,000
Risk-free interest rate											0.48%	0.48%	1.00%	1.00%
Expected volatility											49.07%	49.07%	85.22%	85.22%
Dividend yield											0.00%	0.00%	0.00%	0.00%
Expected average term (years)											7 months 6 days	7 months 6 days	6 months	6 months
Unearned compensation expense \| $	$ 11,972,000									$ 11,972,000	$ 11,972,000
Unearned compensation expense, recognition period											16 months	16 months
Number of options outstanding (in shares)	2,519,831									2,519,831	2,519,831
Potential Proceeds of Additional Shares Authorized \| $		$ 22,781,000		$ 9,084,000
Cashless Exercise Provision
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants exercised (in shares)											0	0	6,000	6,000
Unexpired repurchase rights on shares issued to Arbutus Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned compensation expense \| $	$ 35,967,000									$ 35,967,000	$ 35,967,000
Unearned compensation expense, recognition period											12 months	12 months
2007 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period							3 years
2007 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term							10 years
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period							3 years
2011 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term							10 years
Designated Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)															200,000	200,000
Arbutus Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term											7 years 6 months	7 years 6 months	8 years 9 months 18 days	8 years 9 months 18 days	9 years 7 months 6 days	9 years 7 months 6 days
Options granted (in shares)											1,309,625	1,309,625	431,125	431,125	270,250	270,250
Risk-free interest rate											0.00%	0.00%
Options exercised - Aggregate intrinsic value											$ 5,386,000	CAD 6,887	$ 6,926,000	CAD 7,650	$ 535,000	CAD 551
Number of options outstanding (in shares)	2,290,263									2,290,263	2,290,263		1,530,138		1,730,765					1,648,846
Protiva Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of in-the-money options exercisable \| $	$ 187,000									$ 187,000	$ 187,000
Shares reserved for future exercise								350,457
Option exercise price (in CAD per share) \| CAD / shares								CAD 0.30
Conversion of stock, shares converted (in shares)								0.6752
Protiva Option Plan \| Revised new common shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future exercise								519,073
Protiva Option Plan \| Protiva Share Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual life of exercisable options											1 year 9 months 18 days	1 year 9 months 18 days
Options exercised - Aggregate intrinsic value \| $											$ 1,249,000		$ 378,000		$ 8,000
OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation awards approved to be issued			184,332
Fair value of consideration issued \| $			$ 3,287,000
Options exercisable (in shares)	86,658									86,658	86,658
Weighted average remaining contractual life of exercisable options	8 years 10 months 24 days
Aggregate intrinsic value of in-the-money options exercisable \| $	$ 337,000									$ 337,000	$ 337,000
Weighted average remaining contractual life for options expected to vest											8 years 10 months 24 days	8 years 10 months 24 days
Average exercise price for options expected to vest \| $ / shares	$ 0.57									$ 0.57	$ 0.57
Aggregate intrinsic value of option expected to vest \| $	$ 695,000									$ 695,000	$ 695,000
Total fair value of options that vested during period \| $										620,000
Risk-free interest rate			0.97%
Expected volatility			78.00%
Dividend yield			0.00%
Expected average term (years)			8 years
Business acquisition, fair value amount attributed as pre-combination service and included as part of acquisition consideration \| $			$ 1,127,000
Business acquisition, post-combination attribution recognized as compensation expense \| $			$ 2,160,000
Stock-based compensation expense \| $										$ 463,000
Options exercisable weighted average exercise price \| $ / shares	$ 0.57									$ 0.57	$ 0.57
Number of options outstanding (in shares)	183,040		183,040							183,040	183,040
OnCore Option Plan \| Equivalent number of Company common shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercisable (in shares)	87,269									87,269	87,269
Number of options outstanding (in shares)	184,332		184,332							184,332	184,332

Share Capital - Summary of Warrant Activity (Details) CAD / shares in Units, $ / shares in Units, CAD in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2015 CAD CAD / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2014 CAD CAD / shares shares	Dec. 31, 2013 USD ($) $ / shares	Dec. 31, 2013 CAD CAD / shares shares	Dec. 31, 2015 $ / shares shares	Dec. 31, 2014 $ / shares shares	Dec. 31, 2013 $ / shares shares
Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward]
Balance, Common shares purchasable upon exercise of warrants		379,500		398,250		1,014,728	379,500	398,250	1,014,728
Exercised, Common shares purchasable upon exercise of warrants	(18,750)	(18,750)	(616,478)	(616,478)
Balance, Weighted average exercise price \| (per share)		CAD 2.95		CAD 2.95		CAD 2.90	$ 2.13	$ 2.67	$ 2.72
Exercised, Weighted average exercise price \| (per share)	$ 2.25	CAD 2.88	$ 2.80	CAD 3.09
Balance, Weighted average remaining contractual life	9 months 18 days	9 months 18 days	1 year 9 months 18 days	1 year 9 months 18 days	2 years 8 months 12 days	2 years 8 months 12 days
Balance, Aggregate intrinsic value	$ 879	CAD 1,217	$ 5,343	CAD 5,902	$ 5,298	CAD 5,635
Minimum
Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward]
Balance, Range of exercise prices \| (per share)	$ 2.03	CAD 2.60	$ 2.35	CAD 2.60	$ 2.44	CAD 2.60
Exercised, Range of exercise prices \| (per share)	2.03	2.60	2.35	2.60
Maximum
Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward]
Balance, Range of exercise prices \| (per share)	2.62	3.35	3.03	3.35	$ 3.15	CAD 3.35
Exercised, Range of exercise prices \| (per share)	$ 2.62	CAD 3.35	$ 3.03	CAD 3.35

Share Capital - Black-Scholes Option-pricing Assumptions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Dividend yield	0.00%	0.00%
Expected volatility	49.07%	85.22%
Risk-free interest rate	0.48%	1.00%
Expected average term (years)	7 months 6 days	6 months
Fair value of warrants outstanding (in USD per share)	$ 2.33	$ 12.80
Aggregate fair value of warrants outstanding	$ 883	$ 5,099
Number of warrants outstanding (in shares)	379,500	398,250

Share Capital - Stock Option Activity (Details) CAD / shares in Units, $ / shares in Units, CAD in Thousands, $ in Thousands		12 Months Ended
	Mar. 25, 2015 shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2015 CAD CAD / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2014 CAD CAD / shares shares	Dec. 31, 2013 USD ($) $ / shares shares	Dec. 31, 2013 CAD CAD / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options granted (in shares)	1,125,000	1,309,625	1,309,625
Balance - Number of optioned common shares (in shares)		2,519,831	2,519,831
Arbutus Plans
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)		1,530,138	1,530,138	1,730,765	1,730,765	1,648,846	1,648,846
Balance - Weighted average exercise price \| (per share)		$ 6.29	CAD 6.95	$ 4.32	CAD 4.45	$ 4.54	CAD 4.54
Balance - Aggregate intrinsic value		$ 15,004	CAD 16,573	$ 6,826	CAD 7,030	$ 2,301	CAD 2,300
Options granted (in shares)		1,309,625	1,309,625	431,125	431,125	270,250	270,250
Options granted - Weighted average exercise price \| (per share)		$ 16.57		$ 12.34	CAD 13.63	$ 7.30	CAD 7.52
Options exercised (in shares)		(398,293)	(398,293)	(622,752)	(622,752)	(124,246)	(124,246)
Options exercised - Weighted average exercise price \| (per share)		$ 3.93	CAD 5.03	$ 4.18	CAD 4.62	$ 3.13	CAD 3.22
Options exercised - Aggregate intrinsic value		$ 5,386	CAD 6,887	$ 6,926	CAD 7,650	$ 535	CAD 551
Options forfeited, cancelled or expired - Number of optioned common shares (in shares)		(151,207)	(151,207)	(9,000)	(9,000)	(64,085)	(64,085)
Options forfeited, cancelled or expired - Weighted average exercise price \| (per share)		$ 15.09	CAD 19.29	$ 7.42	CAD 8.20	$ 21.23	CAD 21.87
Balance - Number of optioned common shares (in shares)		2,290,263	2,290,263	1,530,138	1,530,138	1,730,765	1,730,765
Balance - Weighted average exercise price \| (per share)		$ 11.22	CAD 15.53	$ 6.29	CAD 6.95	$ 4.32	CAD 4.45
Balance - Aggregate intrinsic value		$ 994	CAD 1,376	$ 15,004	CAD 16,573	$ 6,826	CAD 7,030

Share Capital - Stock Options Outstanding (Details)	12 Months Ended
Share Capital - Stock Options Outstanding (Details)	Dec. 31, 2015 $ / shares shares
Range 1
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	$ 1.08
Range of Exercise prices - High	$ 1.37
Number of options outstanding (in shares) \| shares	102,800
Weighted average remaining contractual life (years)	4 years 10 months 24 days
Balance - Weighted average exercise price	$ 1.24
Number of options exercisable (in shares) \| shares	102,800
Weighted average exercise price	$ 1.24
Range 2
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	1.52
Range of Exercise prices - High	$ 1.88
Number of options outstanding (in shares) \| shares	120,475
Weighted average remaining contractual life (years)	5 years 9 months 18 days
Balance - Weighted average exercise price	$ 1.66
Number of options exercisable (in shares) \| shares	120,475
Weighted average exercise price	$ 1.66
Range 3
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	2.17
Range of Exercise prices - High	$ 2.78
Number of options outstanding (in shares) \| shares	83,000
Weighted average remaining contractual life (years)	2 years 10 months 24 days
Balance - Weighted average exercise price	$ 2.56
Number of options exercisable (in shares) \| shares	83,000
Weighted average exercise price	$ 2.56
Range 4
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	3.24
Range of Exercise prices - High	$ 4.70
Number of options outstanding (in shares) \| shares	288,960
Weighted average remaining contractual life (years)	5 years 4 months 24 days
Balance - Weighted average exercise price	$ 3.84
Number of options exercisable (in shares) \| shares	268,900
Weighted average exercise price	$ 3.83
Range 5
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	5.10
Range of Exercise prices - High	$ 7.50
Number of options outstanding (in shares) \| shares	261,923
Weighted average remaining contractual life (years)	7 years 8 months 12 days
Balance - Weighted average exercise price	$ 6.33
Number of options exercisable (in shares) \| shares	175,112
Weighted average exercise price	$ 6.12
Range 6
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	8.38
Range of Exercise prices - High	$ 10.04
Number of options outstanding (in shares) \| shares	176,813
Weighted average remaining contractual life (years)	8 years 8 months 12 days
Balance - Weighted average exercise price	$ 9.35
Number of options exercisable (in shares) \| shares	99,189
Weighted average exercise price	$ 9.24
Range 7
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	10.69
Range of Exercise prices - High	$ 13.39
Number of options outstanding (in shares) \| shares	129,417
Weighted average remaining contractual life (years)	8 years 2 months 12 days
Balance - Weighted average exercise price	$ 11.93
Number of options exercisable (in shares) \| shares	79,252
Weighted average exercise price	$ 11.90
Range 8
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	13.40
Range of Exercise prices - High	$ 17.57
Number of options outstanding (in shares) \| shares	1,126,875
Weighted average remaining contractual life (years)	9 years 2 months 12 days
Balance - Weighted average exercise price	$ 17.02
Number of options exercisable (in shares) \| shares	10,002
Weighted average exercise price	$ 17.57
Total Range
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low	1.08
Range of Exercise prices - High	$ 17.57
Number of options outstanding (in shares) \| shares	2,290,263
Weighted average remaining contractual life (years)	7 years 10 months 24 days
Balance - Weighted average exercise price	$ 11.22
Number of options exercisable (in shares) \| shares	938,730
Weighted average exercise price	$ 4.98

Share Capital - Non-vested Stock Option Activity (Details)		12 Months Ended
	Mar. 25, 2015 shares	Dec. 31, 2015 CAD / shares shares	Dec. 31, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)		441,230	441,230
Non-vested, beginning balance, weighted average fair value \| (per share)		CAD 9.30	$ 8.42
Options granted (in shares)	1,125,000	1,309,625	1,309,625
Options granted \| (per share)		CAD 15.20	$ 11.89
Options vested (in shares)		(250,461)	(250,461)
Options vested \| (per share)		CAD 8.77	$ 6.86
Non-vested options forfeited (in shares)		(148,853)	(148,853)
Non-vested options forfeited \| (per share)		CAD 14.27	$ 11.16
Non-vested, ending balance (in shares)		1,351,541	1,351,541
Non-vested, ending balance, weighted average fair value \| (per share)		CAD 15.69	$ 11.34

Share Capital - Weighted Average Option Pricing Assumptions (Details) - Arbutus Plans	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	76.88%	101.08%	111.61%
Risk-free interest rate	1.10%	2.25%	2.39%
Expected average option term	7 years 6 months	8 years 9 months 18 days	9 years 7 months 6 days

Share Capital - Outstanding Options Under the Protiva Option Plan (Details)	12 Months Ended
	Dec. 31, 2015 CAD / shares shares	Dec. 31, 2015 CAD / shares $ / shares shares	Dec. 31, 2014 CAD / shares shares	Dec. 31, 2014 CAD / shares $ / shares shares	Dec. 31, 2013 CAD / shares shares	Dec. 31, 2013 CAD / shares $ / shares shares	Dec. 31, 2015 $ / shares shares	Dec. 31, 2014 $ / shares shares	Dec. 31, 2013 $ / shares shares	Dec. 31, 2012 CAD / shares shares	Dec. 31, 2012 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	2,519,831	2,519,831					2,519,831
Protiva Share Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	67,000	67,000	433,740	433,740	472,885	472,885	67,000	433,740	472,885	475,885	475,885
Balance, Weighted average exercise price \| (per share)	CAD 0.30	CAD 0.30	CAD 0.30	CAD 0.30	CAD 0.30	CAD 0.30	$ 0.22	$ 0.27	$ 0.29	CAD 0.30	$ 0.30
Options exercised (in shares)	(358,675)	(358,675)	(38,145)	(38,145)	(2,000)	(2,000)
Options exercised - Weighted average exercise price \| (per share)	CAD 0.30	CAD 0.23	CAD 0.30	CAD 0.27	CAD 0.30	CAD 0.29
Options forfeited, canceled or expired (in shares)	(8,065)	(8,065)	(1,000)	(1,000)	(1,000)	(1,000)
Options forfeited, cancelled or expired - Weighted average exercise price \| (per share)	CAD 0.30	CAD 0.23	CAD 0.30	CAD 0.27	CAD 0.30	CAD 0.29
Equivalent number of Company common shares \| Protiva Share Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	45,236	45,236	292,845	292,845	319,274	319,274	45,236	292,845	319,274	321,299	321,299
Options exercised (in shares)	(242,164)	(242,164)	(25,754)	(25,754)	(1,350)	(1,350)
Options forfeited, canceled or expired (in shares)	(5,445)	(5,445)	(675)	(675)	(675.00)	(675.00)

Share Capital - Outstanding Options Under the OnCore Option Plan (Details)	10 Months Ended
	Dec. 31, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	2,519,831
OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	183,040
Balance - Weighted average exercise price \| $ / shares	$ 0.57
Options exercised (in shares)	0
Options forfeited, canceled or expired (in shares)	0
Balance - Number of optioned common shares (in shares)	183,040
Balance - Weighted average exercise price \| $ / shares	$ 0.57
Equivalent number of Company common shares \| OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	184,332
Options exercised (in shares)	0
Options forfeited, canceled or expired (in shares)	0
Balance - Number of optioned common shares (in shares)	184,332

Share Capital - Non-vested Stock Option Activity OnCore Option Plan (Details)	10 Months Ended		12 Months Ended
	Dec. 31, 2015 CAD / shares shares	Dec. 31, 2015 $ / shares shares	Dec. 31, 2015 CAD / shares shares	Dec. 31, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)			441,230	441,230
Non-vested, beginning balance, weighted average fair value \| (per share)			CAD 9.30	$ 8.42
Options vested (in shares)			(250,461)	(250,461)
Options vested \| (per share)			CAD 8.77	$ 6.86
Non-vested options forfeited (in shares)			(148,853)	(148,853)
Non-vested, ending balance (in shares)	1,351,541	1,351,541	1,351,541	1,351,541
Non-vested, ending balance, weighted average fair value \| (per share)	CAD 15.69	$ 11.34	CAD 15.69	$ 11.34
OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)	128,510	128,510
Non-vested, beginning balance, weighted average fair value \| $ / shares		$ 16.42
Options vested (in shares)	(32,128)	(32,128)
Options vested \| $ / shares		$ 16.42
Non-vested options forfeited (in shares)	0	0
Non-vested, ending balance (in shares)	96,382	96,382	96,382	96,382
Non-vested, ending balance, weighted average fair value \| $ / shares		$ 16.42		$ 16.42
Equivalent number of Company common shares \| OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)	129,417	129,417
Options vested (in shares)	(32,354)	(32,354)
Non-vested options forfeited (in shares)	0	0
Non-vested, ending balance (in shares)	97,063	97,063	97,063	97,063

Share Capital - Location Of Expenses for Stock-based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 22,093	$ 3,283	$ 903
Research, development, collaborations and contracts expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	7,868	2,343	622
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 14,225	$ 940	$ 281

Government Grants and Refundable Investment Tax Credits (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Government Grants and Refundable Investment Tax Credits [Line Items]
Contracts revenue		$ 13,309	$ 11,738	$ 10,425
Revenue from government grants		1,245	172
Investment tax credit		$ 196	$ 52
ISARIC
Government Grants and Refundable Investment Tax Credits [Line Items]
Contracts revenue	$ 1,098

Income Taxes (Details) $ in Thousands		12 Months Ended
Income Taxes (Details) $ in Thousands	Nov. 23, 2011 CAD	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Income Taxes [Line Items]
Canadian federal and provincial income tax rate		26.00%	26.00%	26.00%
Research and development credits		$ 483
Scientific research and experimental development expenditures available for indefinite carry-forward		13,932	$ 6,578
Deferred tax assets, operating loss carryforwards, subject to expiration		17,235
Patent tax refund percentage	75.00%
Income tax refund maximum from patents		24	0	$ 10
Total deferred tax assets			37,818
Valuation allowance		41,494	37,818
Maximum
Income Taxes [Line Items]
Income tax refund maximum from patents \| CAD	CAD 8,000,000
Investment tax credit carryforward
Income Taxes [Line Items]
Investment tax credits available to reduce Canadian federal income taxes		7,969	7,866
Investment tax credits available to reduce provincial income taxes		3,869	3,401
Research tax credit carryforward
Income Taxes [Line Items]
Scientific research and experimental development expenditures available for indefinite carry-forward		51,823	49,907
Deferred tax assets, operating loss carryforwards, subject to expiration		$ 24,745	25,301
Recast adjustment
Income Taxes [Line Items]
Total deferred tax assets			8,424
Valuation allowance			$ 8,424

Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Computed taxes (recoveries) at Canadian federal and provincial tax rates	$ (20,100)	$ (10,097)	$ (3,486)
Differences due to change in enacted tax rates	0	0	(9)
Permanent and other differences	8,113	3,498	1,088
Change in valuation allowance - other	3,676	6,599	2,407
Difference due to income taxed at foreign rates	(7,874)	0	0
Deferred income tax recovery	$ (16,185)	$ 0	$ 0

Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Components of Deferred Tax Assets [Line Items]
Non-capital loss carryforwards	$ 13,932	$ 6,578
Research and development deductions	13,474	14,006
Book amortization in excess of tax	2,142	2,745
Share issue costs	777	1,195
Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes	281	4,086
Tax value in excess of accounting value in lease inducements	77	65
In-process research and development	(146,324)	0
Upfront license fees	629	0
Total deferred tax liabilities	(104,830)
Total deferred tax assets		37,818
Valuation allowance	(41,494)	(37,818)
Net deferred tax liabilities	(146,324)
Net deferred tax assets		0
Federal
Components of Deferred Tax Assets [Line Items]
Investment tax credits	6,303	5,821
Provincial
Components of Deferred Tax Assets [Line Items]
Investment tax credits	$ 3,879	$ 3,322

Contingencies and Commitments - Minimum Rent and Estimated Operating Cost Commitment, Net Lease Inducements (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Year ended December 31, 2016	$ 1,229
Year ended December 31, 2017	938
Year ended December 31, 2018	938
Year ended December 31, 2019	547
Future minimum rent and estimated operating cost commitment, net of lease inducements	$ 3,652

Contingencies and Commitments (Details) CAD in Thousands			1 Months Ended					12 Months Ended				53 Months Ended
Contingencies and Commitments (Details) CAD in Thousands	Jan. 16, 2015 USD ($)	Nov. 29, 2012 USD ($)	Jan. 31, 2015 USD ($)	Nov. 30, 2014 USD ($)	Oct. 31, 2014 USD ($) program	Sep. 30, 2014 USD ($)	Feb. 28, 2014 USD ($) compound_series	Dec. 31, 2015 USD ($)	Dec. 31, 2015 CAD	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2004 USD ($)	Mar. 31, 2004 CAD	Dec. 31, 2015 CAD	Jan. 11, 2015 USD ($)	Dec. 30, 2014 USD ($) compound_series
Contingencies and Commitments [Line Items]
Lease expense								$ 1,158,000		$ 1,133,000	$ 1,225,000
Percent of costs funded by TPC												27.00%	27.00%
Maximum contribution for product												$ 7,179,000	CAD 9,330
Cumulative contribution for product								$ 2,675,000	CAD 3,702
Royalty guarantees commitments percentage								2.50%	2.50%
Increase in fair value of contingent consideration								$ 770,000		0	0
OnCore \| Enantigen
Contingencies and Commitments [Line Items]
Business combination, high end of payment upon achievement of certain triggering events					$ 21,000,000
Programs in pre-clinical development \| program					2
Business combination, regulatory, development and sales milestone payments estimated fair value								7,497,000							$ 6,727,000
Increase in fair value of contingent consideration								770,000
Arbitration with the University of British Columbia
Contingencies and Commitments [Line Items]
Loss contingency, damages sought for allegedly unpaid royalties	$ 3,500,000
Marina
Contingencies and Commitments [Line Items]
Upfront fee		$ 300,000
Milestone payment		$ 3,250,000									200,000
Arcturus
Contingencies and Commitments [Line Items]
Milestone payment			$ 250,000
Blumberg and Drexel \| OnCore
Contingencies and Commitments [Line Items]
License fee				$ 50,000			$ 150,000
Development and regulatory milestones payment per licensed compound series, maximum				$ 1,000,000			3,500,000
Sales performance milestones payment per licensed product, maximum							$ 92,500,000
Number of series of compounds \| compound_series							3
Blumberg \| Arbutus Inc.
Contingencies and Commitments [Line Items]
Research funding per year under research collaboration and funding agreement					$ 1,000,000
Research funding period					3 years
Research funding period, renewable option					3 years
Research funding agreement exclusive license upfront payment					$ 100,000
Research funding agreement exclusive license maximum development and regulatory milestone payments					8,100,000
Research funding agreement license maximum commercialization milestone payments					$ 92,500,000
NeuroVive \| Arbutus Inc.
Contingencies and Commitments [Line Items]
License fee						$ 1,000,000
Cytos \| Arbutus Inc.
Contingencies and Commitments [Line Items]
Development and regulatory milestones payment per licensed compound series, maximum																$ 67,000,000
Sales performance milestones payment per licensed product, maximum																$ 110,000,000
Number of series of compounds \| compound_series																6
Marqibo
Contingencies and Commitments [Line Items]
Royalty revenue								240,000
Royalty payable								6,000		$ 190,000	$ 1,000
Royalties paid or accrued								12,000
Contractual obligation								$ 2,664,000						CAD 3,687

Concentrations of Business Risk - Net Liquidity of the Company (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Cash, cash equivalents and short-term investments	$ 181,304	$ 112,161
Less: Accounts payable and accrued liabilities	(8,827)	(9,328)
Net liquidity	$ 172,477	$ 102,833

- Definition

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

+ References + Details

Concentrations of Business Risk - Foreign Currency Exposure (Details) CAD in Thousands, $ in Thousands	Dec. 31, 2015 USD ($)	Dec. 31, 2015 CAD	Dec. 31, 2014 USD ($)	Dec. 31, 2014 CAD
Intercompany Foreign Currency Balance [Line Items]
Cash, cash equivalents and short-term investments \| $	$ 181,304		$ 112,161
Accounts receivable \| $	1,008		1,903
Accrued revenue \| $	128		538
Accounts payable and accrued liabilities \| $	$ (8,827)		$ (9,328)
Foreign currency exposure
Intercompany Foreign Currency Balance [Line Items]
Cash, cash equivalents and short-term investments		CAD 213,419		CAD 75,224
Accounts receivable		1,071		1,942
Accrued revenue		178		624
Accounts payable and accrued liabilities		(8,061)		(4,494)
Exposure to US dollar		CAD 206,607		CAD 73,296

- Definition

+ References + Details

Supplementary Information (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Trade accounts payable	$ 2,610	$ 2,044
Research and development accruals	2,358	2,391
License fee accruals	0	250
Professional fee accruals	640	1,294
Deferred lease inducements	297	250
Payroll accruals	2,331	2,873
Other accrued liabilities	591	226
Accounts payable and accrued liabilities	$ 8,827	$ 9,328

Interim Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 12,686	$ 4,065	$ 3,440	$ 4,682	$ 4,350	$ 4,362	$ 1,811	$ 4,430	$ 24,873	$ 14,953	$ 15,465
Loss from operations	(11,758)	(58,138)	(14,420)	(18,006)	(10,747)	(6,844)	(9,423)	(5,958)	(102,322)	(33,434)	(12,152)
Net loss	$ (5,264)	$ (28,982)	$ (14,886)	$ (11,989)	$ (6,168)	$ (8,604)	$ (6,081)	$ (17,984)	$ (61,121)	$ (38,837)	$ (14,063)
Basic and diluted net loss per share (in USD per share)	$ (0.10)	$ (0.57)	$ (0.27)	$ (0.40)	$ (0.27)	$ (0.39)	$ (0.28)	$ (0.91)	$ (1.34)	$ (1.80)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Subsequent Events (Details) - Monsanto - PADCo. - Subsequent event $ in Thousands	Mar. 09, 2016 USD ($)
Subsequent Event [Line Items]
Business acquisition, percentage of outstanding shares acquired	100.00%
Optional exercised contractual option, amount	$ 1,000

Nature of Business and Future Operations Narrative (Details)	Dec. 31, 2015 subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Wholly-owned subsidiaries	4

Property and Equipment (Details)	12 Months Ended
Property and Equipment (Details)	Dec. 31, 2015 USD ($)
Property, Plant and Equipment [Abstract]
Asset impairment charges	$ 0

Concentrations of Business Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Accounts receivable	$ 1,008	$ 1,903