Tekmira's Partner Hana Biosciences Presents Marqibo® Data at American Society of Hematology Meeting

Dec 10, 2007

Tekmira's Partner Hana Biosciences Presents Marqibo® Data at American Society of Hematology Meeting

For immediate release: December 10, 2007

Vancouver, BC – Tekmira Pharmaceuticals Corporation ("Tekmira"; TSX:TKM) reported today that its partner Hana Biosciences, Inc. (NASDAQ: HNAB) presented Marqibo® (vincristine sulfate injection, OPTISOMETM) clinical and non-clinical data at the 49th Annual Meeting of the American Society of Hematology (ASH) on December 8, 2007. The ASH meeting is being held December 8-11, 2007 in Atlanta, Georgia.

Hana Biosciences is developing and commercializing Marqibo under a licensing partnership agreement with Tekmira. Hana Biosciences is paying development costs and will also pay to Tekmira milestones based on progress and royalties based on sales.

Hana reported that one of its clinical investigators, Deborah A. Thomas, M.D. from the University of Texas M. D. Anderson Cancer Center, presented clinical data showing that Marqibo with or without pulse dexamethasone appears to have clinically meaningful activity in heavily pre-treated adults with Acute Lymphoblastic Leukemia (ALL).

In an oral session on acute lymphoblastic leukemia therapy, Dr. Thomas presented publication #858, "Safety and Efficacy of Marqibo (Vincristine Sulfate Liposomes Injection, OPTISOME™) for the Treatment of Adults with Relapsed or Refractory Acute Lymphoblastic Leukemia (ALL)" during the session entitled Acute Lymphocytic Leukemias: Therapy, excluding Transplantation.

Data from two clinical trials were integrated for the presentation: a Phase 2 trial of single agent Marqibo given at 2 mg/m2 (no dose capping) every two weeks; and a multi-center dose-escalation Phase 1 trial of Marqibo in combination with pulse dexamethasone administered on a weekly schedule. In total, 52 adult patients with relapsed or refractory ALL were treated in the two studies combined, and all patients had previously received and failed conventional vincristine containing therapy. There were no restrictions on the number of prior therapies. Out of the 52 patients, eight complete remissions and three partial remissions were observed for an overall response rate of 21 percent. An additional 12 patients (23 percent) achieved hematological improvements such as clearance of marrow blasts and platelet transfusion independence. Five responders were able to undergo allogeneic stem cell transplantation following therapy with Marqibo. The maximum-tolerated dose was established in the Phase 1 trial as 2.25 mg/m2 without dose-capping.

Timothy M. Ruane, Tekmira President and CEO, said the clinical data presented at the ASH meeting continues to support the Marqibo development plan being implemented by Hana. "We are pleased with Hana’s progress and the data presented in acute lymphoblastic leukemia is consistent with their Marqibo clinical strategy including the ongoing phase 2 registration-enabling rALLy study and their planned phase 3 trial in front-line ALL."

Hana Biosciences also presented non-clinical data for Marqibo during the Lymphoma: Pre−Clinical: Chemotherapy and Biologic session under publication #1403, "Marqibo (Vincristine Sulfate Liposomes Injection, OPTISOME™) Concentrates Vincristine in Tumor Tissue and Lymphoid Malignancy Oriented Tissues in Tumor−Bearing Mice." The study showed that Marqibo’s Optisome™-encapsulation of vincristine resulted in targeted delivery and concentration of vincristine in tumor tissue, bone marrow, lymph nodes, liver and spleen, and maintenance of significant tissue drug concentrations for an extended period of time compared to conventional vincristine. Specifically, lymphoid malignancy-oriented tissue and intra-tumor vincristine concentrations were greater in Marqibo-treated mice compared to conventional vincristine-treated mice resulting in greater vincristine exposure. Marqibo administration resulted in a three-fold increased concentration of vincristine in bone marrow at 48 hours and maintained significant tissue concentrations for several days compared to conventional vincristine. The ability of Marqibo to target these tissues and organs makes it particularly attractive as a treatment for hematologic malignancies such as leukemia, myeloma and lymphoma. 

About Marqibo® (vincristine sulfate injection, OPTISOME™)

Marqibo has received U.S. Food and Drug Administration (FDA) Orphan Drug designation and Fast Track Status in adult ALL. Marqibo is currently enrolling patients in the rALLy study, a registration-enabling clinical trial in relapsed ALL. A pilot Phase 2 clinical trial in metastatic uveal melanoma is also currently enrolling patients. A Phase 3 trial in front-line elderly ALL is planned for 2008.

Marqibo, a novel, targeted, Optisomal formulation of vincristine, has shown promising anti-cancer activity in patients with acute lymphoblastic leukemia, non-Hodgkin’s lymphoma and melanoma in several clinical trials. Vincristine is FDA-approved as a single agent and in combination regimens for the treatment of hematologic malignancies such as lymphomas and leukemias. Vincristine, a microtubule inhibitor, kills cancer cells when they enter a very specific point in the cell cycle, and its efficacy is concentration- and exposure duration-dependent. Marqibo is believed to extend the circulation time of vincristine in the bloodstream, increase targeting of the drug to malignant cells, and enhance exposure duration at the site of the disease. Unlike regular vincristine, Marqibo is dosed based on patient body surface area without the need to limit the dose to avoid neurotoxicities.

About Acute Lymphoblastic Leukemia (ALL)

Approximately 4,000 cases of ALL are diagnosed annually in the United States. While cure rates for childhood ALL have steadily improved to nearly 90 percent, adult ALL reported cure rates seldom exceed 40 percent. The poorer outcome in adult ALL has been attributed to an increased frequency of high-risk leukemia with greater resistance, poorer tolerance of and compliance with treatment, reluctance to accept toxic effects, and less effective treatment regimens as compared with childhood ALL. Currently, there are no fully-approved agents for adult Philadelphia chromosome negative ALL salvage, nor is there a consensus on the most appropriate regimen in the relapsed setting. Ongoing efforts are needed to investigate agents for this indication, as well as incorporate active agents, once identified, into front-line therapy.

About Hana Biosciences, Inc.

Hana Biosciences, Inc. (NASDAQ: HNAB) is a South San Francisco, CA-based

biopharmaceutical company focused on acquiring, developing, and commercializing innovative products to advance cancer care. The company is committed to creating value by building a world-class team, accelerating the development of lead product candidates, expanding its pipeline by being the alliance partner of choice, and nurturing a unique company culture. Additional information on Hana Biosciences can be found at www.hanabiosciences.com.

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.

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