Onyx Pharmaceuticals acquires license option on novel JAK2 inhibitors from S*BIO

Onyx Pharmaceuticals, Inc. has announced that it has acquired an option to license rights to SB1518, an orally available, potent, and selective inhibitor of Janus Kinase 2 (JAK2), and SB1578, also a JAK2 inhibitor, from S*BIO Pte Ltd based in Singapore.

Under the terms of the agreement, Onyx has obtained option rights to exclusively develop and commercialize SB1518 (designated by Onyx as ONX 0803) and SB1578 (designated by Onyx as ONX 0805) for all potential indications in the United States, Canada, and Europe. S*BIO will retain responsibility for all development costs prior to option exercise, after which Onyx will assume development costs for the U.S., Canada, and Europe subject to S*BIO's option to fund a portion of the development costs in return for enhanced royalties on any future product sales. Upon option exercise for each compound, S*BIO will receive a one-time fee, milestones upon achievement of certain development and sales triggers and royalties on future product sales. Under the terms of the agreement, in December 2008, Onyx made a $25 million payment to S*BIO, including an up-front payment and an equity investment. After recognizing R&D expense related to the S*BIO transaction, Onyx continues to anticipate profitability for the full year 2008 on a non-GAAP basis, excluding stock-based compensation.

"JAK2 is implicated across a broad range of difficult-to-treat illnesses, including cancer and autoimmune diseases, and is one of the most exciting potential new targets in cancer therapy today. These compounds fit with our vision of exploring cutting-edge therapies with broad potential utility," said N. Anthony Coles, M.D., president and chief executive officer of Onyx. "This transaction exemplifies our approach of expanding our product portfolio through deals with staged investments as value-creating events occur."

SB1518 (ONX 0803) has been designed to suppress the overactivity of mutant JAK2 and is currently in multiple Phase 1 studies. Data from these Phase 1 dose-ranging studies, evaluating the compound in patients with primary myelofibrosis, are anticipated in the first half of 2009. SB1578 (ONX 0805) is currently in preclinical development.

Under normal circumstances, activation of JAK2 stimulates blood cell production. Genetic mutations in the JAK2 enzyme result in up-regulated activity and are implicated in myeloproliferative diseases (MPD), conditions characterized by an overproduction of blood cells in the bone marrow. The MPD conditions where JAK2 mutations are most commonly found are: polycythemia vera (PV), essential thrombocytopenia (ET), and primary myelofibrosis (MF). The JAK2 signaling pathway is also known to play a critical role in the proliferation of certain types of cancer cells and the anti-inflammatory pathway, suggesting JAK2 inhibitors may be able to play a role in the treatment of solid tumors and other diseases such as rheumatoid arthritis or psoriasis.

"Given its specificity for the JAK2 kinase and the encouraging early clinical activity and safety observed so far, we believe that SB1518 (ONX 0803) and SB1578 (ONX 0805) may be effective and well-tolerated treatments for a number of debilitating conditions with potential applicability beyond MF and MPD," said Juergen Lasowski, Ph.D., senior vice president of corporate development at Onyx.

http://www.onyx-pharm.com/