Clovis Oncology and Array BioPharma Announce Agreement to Discover Novel Mutant KIT Inhibitor

Clovis Oncology, Inc.

and Array BioPharma

announced today an agreement for the discovery of a novel KIT inhibitor targeting resistance mutations for the treatment of GIST. GIST is a gastrointestinal cancer diagnosed each year in more than 12,000 patients in the US and EU and 2,500 in Japan. Currently approved therapies for GIST include the tyrosine kinase inhibitors (TKIs) Gleevec® (imatinib), and Sutent® (sunitinib), typically used first- and second-line respectively. Each inhibits some KIT mutations, but acquired resistance due to secondary KIT mutations occurs in the majority of GIST patients, resulting in disease progression. Patients who present with metastatic GIST have a five-year survival rate of approximately 50 percent.