Preliminary clinical data show promise in chronic lymphocytic leukemia; preclinical data support additional indications

REDWOOD CITY, CA, and SEATTLE, WA, USA | August 28, 2009 | Facet Biotech Corporation (Nasdaq: FACT) and Trubion Pharmaceuticals, Inc. (Nasdaq: TRBN) today announced an agreement for the joint worldwide development and commercialization of TRU-016, a product candidate in phase 1 clinical development for chronic lymphocytic leukemia (CLL).

TRU-016 is a CD37-directed Small Modular ImmunoPharmaceutical (SMIP(TM)) protein therapeutic. The collaboration agreement includes TRU-016 in all indications and all other CD37-directed protein therapeutics.

"TRU-016 is a promising therapeutic with impressive preclinical and preliminary clinical data for CLL that will greatly enhance our pipeline and support a key strategic objective, which is to build a robust oncology portfolio," said Faheem Hasnain, president and CEO of Facet Biotech. "After a thorough evaluation of a number of programs over the past several months, we concluded that TRU-016 was a particularly compelling program and a great fit with our pipeline and expertise. While the novel approach to protein therapeutics is supported by a solid biological rationale and validated clinical data in CLL, TRU-016 may have broad utility in additional indications, including non-Hodgkin’s lymphoma and multiple sclerosis. Through this collaboration, we can leverage and extend our significant expertise in the research and development of protein therapeutics and we look forward to playing a key role in advancing this important program with our partners at Trubion."

"In considering alliance opportunities for TRU-016 we sought to retain meaningful economics in this exciting first-in-class product candidate, while enabling aggressive joint development with a partner who shared our vision and brought complementary experience and resources to the alliance," said Peter Thompson, M.D., FACP, president, CEO and chairman of Trubion. "We are delighted to have Facet as our partner. Coupled with our own strengths in the discovery and development of novel protein therapeutics, their expertise will afford us the opportunity to pursue the clinical development and commercialization of TRU-016 and other CD37-directed therapeutics in the most aggressive manner possible."

Under the terms of the collaboration agreement, Trubion will receive an upfront payment of $20 million and may receive up to $176.5 million in additional contingent payments upon the achievement of certain development, regulatory and sales milestones. The companies will share equally the costs of all development, commercialization and promotional activities and all global operating profits. In addition, Facet will purchase 2,243,649 shares of newly issued Trubion common stock for an aggregate purchase price of $10 million.

About TRU-016

TRU-016 is a novel CD37-directed therapy for the treatment of B-cell malignancies, such as chronic lymphocytic leukemia, or CLL, as well as certain autoimmune and inflammatory disease indications. TRU-016 uses a different mechanism of action than CD20-directed therapies. As a result, its novel design may provide patients with improved therapeutic options and enhance efficacy when used alone or in combination with chemotherapy and/or CD20-directed therapeutics. In June 2009, positive results following preliminary analysis from the Phase 1 clinical trial of TRU-016 for the treatment of CLL were announced. The objectives of the Phase 1 TRU-016 CLL study were to define safety and tolerability, identify a maximum tolerated dose, evaluate pharmacology and pharmacodynamics, and assess preliminary clinical activity.

About Facet Biotech

Facet Biotech is a biotechnology company dedicated to advancing its pipeline of four clinical-stage products, leveraging its research and development capabilities to identify and develop new oncology drugs and applying its proprietary next-generation protein engineering technologies to potentially improve the clinical performance of protein therapeutics. Facet Biotech Corporation launched in December 2008 as a spin-off from PDL BioPharma, Inc.

About Trubion

Trubion is a biopharmaceutical company that is creating a pipeline of novel protein therapeutic product candidates to treat autoimmune and inflammatory diseases and cancer. The Company’s mission is to develop a variety of first-in-class and best-in-class product candidates, customized for optimal safety, efficacy and convenience that it believes may offer improved patient experiences. Trubion’s current product candidates are novel single-chain protein, or SMIP, therapeutics, and are designed using its custom drug assembly technology. Trubion’s product pipeline includes CD20-directed SMIP therapeutics such as TRU-015 and SBI-087 for autoimmune and inflammatory diseases, developed under the Company’s Wyeth collaboration. Trubion’s product pipeline also includes Trubion’s proprietary product candidate, TRU-016, a novel CD37-targeted therapy for the treatment of B-cell malignancies that is currently in Phase 1 clinical evaluation. In addition to Trubion’s current clinical stage product pipeline, the Company is also developing its multi-specific SCORPION technology, both for targeting cell-surface molecules like CD79b and HLA-DR, as well as simultaneously neutralizing soluble ligands like TNF and IL-6. More information is available in the investors section of Trubion’s website: http://investors.trubion.com/index.cfm.

SOURCE Trubion Pharmaceuticals Inc.