SOUTH SAN FRANCISCO, Calif.–(BUSINESS WIRE)–Oct. 6, 2015– Exelixis, Inc.(NASDAQ:EXEL) today announced positive overall survival (OS) results from coBRIM, the phase 3 pivotal trial evaluating cobimetinib, a specific MEK inhibitor discovered by Exelixis, in combination with vemurafenib in previously untreated patients with unresectable locally advanced or metastatic melanoma carrying a BRAF V600 …