S* BIO and Onyx Pharmaceuticals expanded their development collaboration and option and license commercialization agreement for S*BIO's JAK2 inhibitors, SB1518 and SB1578, also known as ONX 0803 and ONX 0805, respectively. The expanded agreement builds upon the development and commercialization collaboration between the two companies announced in January 2009.
Onyx will provide $20 million in funding to broaden and accelerate the existing development program for both compounds. The program will be expanded to include new indications for hematologic malignancies and myeloproliferative disorders. S*BIO will continue to perform the clinical development of SB1518 and preclinical through clinical development of SB1578.
The original agreement, valued at up to $550 million, included a $25 million up-front equity purchase, as well as eligibility for option and license fees, development and sales milestone payments, and double-digit royalties on any sales.
JAK2 inhibitors are implicated across a broad range of difficult-to-treat illnesses, including cancer and autoimmune diseases, in which patients have mutations and rearrangements of the JAK2 gene. SB1518 is a small molecule JAK2-selective kinase inhibitor that has demonstrated activity against both the wild-type JAK2 kinase and the JAK2 kinase with the V617F mutation. The V617F mutation is found in high frequencies in myeloproliferative disorders such as myelofibrosis (MF). It is estimated that approximately 50% of patients with MF possess the JAK2 mutation. SB1518 also provides new development pathways for other hematologic malignancies with mutations and rearrangements in the JAK2 gene.
Onyx can elect to exercise its exclusive options for SB1518 and SB1578 separately and independently at certain predetermined stages of development for each compound in all indications in the U. S., Canada, and Europe. S*BIO would retain rights to develop and commercialize SB1518 and SB1578 in the rest of the world.