Tekmira Pharmaceuticals Provides Update on Ongoing Legal Dispute with Protiva BiotherapeuticsFor immediate release: October 16, 2007

Vancouver, BC – Tekmira Pharmaceuticals Corporation (“Tekmira”; TSX:TKM) today provided an update on the ongoing legal dispute with Protiva Biotherapeutics Inc. (“Protiva”) in response to an announcement made by Protiva. On October 16, 2007, Protiva announced an agreement with Merck & Co., Inc. (“Merck”; NYSE:MRK) whereby Protiva licensed to Merck rights to technology in the field of RNA interference (“RNAi”) on a non-exclusive basis.

There is an ongoing legal dispute between Tekmira and Protiva in British Columbia Supreme Court. The dispute relates to the rights of certain drug delivery technology for the delivery of small interfering RNA (“siRNA”), the molecules that mediate RNA interference. As part of the contractual agreements that created Protiva in 2001, Tekmira believes it has retained all rights to the delivery of siRNA. Tekmira also believes that any technology advancements made by Protiva and its collaborators or by Tekmira, for the delivery of siRNA, are either owned by Tekmira or should be licensed to Tekmira on an exclusive, worldwide, paid-up and royalty-free basis.

In response to today’s announcement, Tekmira will be amending its statement of claim in British Columbia Supreme Court to include a claim on any and all consideration received by Protiva in connection with the licensing of the disputed technology. This includes upfront or one-time payments as well as future milestones and royalties. Further, Tekmira will amend its statement of claim to seek a ruling that will effectively terminate Merck’s license to the disputed technology.

Timothy M. Ruane, President and Chief Executive Officer of Tekmira, said Tekmira will continue to defend it rights vigorously in British Columbia Supreme Court. “As rightful owners of the disputed technology, we will continue to defend our contractual and legal position against Protiva and any of its current or future licensees, including Merck. We are confident in our position and we will continue our focus on bringing resolution to this dispute for the benefit of Tekmira and its shareholders, whether through the courts or other mechanisms.”

Tekmira is continuing to develop its siRNA delivery technology with its collaborator, Alnylam Pharmaceuticals, Inc., a leader in the development of therapeutics based on siRNA.

About Tekmira
Tekmira Pharmaceuticals Corporation is a Canadian biopharmaceutical company developing and commercializing proprietary drugs and drug delivery systems to improve the treatment of cancer and other diseases. Further information about Tekmira and this news release can be found at www.tekmirapharm.com.

Forward Looking Statements
There are forward-looking statements and information contained herein that are not based on historical fact, including without limitation statements containing the words “believes,” “may,” “plans,” “will,” “estimate,” “continue,” “anticipates,” “intends,” “expects,” and similar expressions, and the negative of such expressions. Such forward-looking statements and information involve known and unknown risks, uncertainties and other factors that may cause the actual results, events or developments to be materially different from any future results, events or developments expressed or implied by such forward-looking statements and information. Such factors include, among others, Tekmira’s stage of development, lack of product revenues, additional capital requirements, risks associated with the completion of clinical trials and obtaining regulatory approval to market Tekmira’s products, the ability to protect its intellectual property and dependence on collaborative partners. These factors should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements or information. Tekmira disclaims any obligation to update any such factors or to publicly announce the result of any revisions to any of the forward-looking statements or information contained herein to reflect future results, events or developments, except as required by law.

Contact Information for Tekmira Pharmaceuticals Corporation Investors
Ian Mortimer
Senior Vice President, Finance and Chief Financial Officer
Phone: 604-419-3200

Media
Nicole Rizgalla
James Hoggan & Associates Inc.
Phone: 604-742-4268
Email: nrizgalla@hoggan.com

The common shares of Tekmira are traded on the Toronto Stock Exchange under the trading symbol “TKM”.