Exelixis has announced that the FDA has approved Cotellic (cobimetinib) as a treatment for patients with BRAF V600E or V600K mutation-positive unresectable or metastatic melanoma in combination with vemurafenib.

Cotellic and vemurafenib are not used to treat melanoma with a normal BRAF gene. Cotellic is a selective inhibitor of MEK that was discovered by Exelixis and is the subject of a worldwide collaboration agreement between Exelixis and Genentech, a member of the Roche Group. The FDA’s go-ahead marks the second regulatory approval for Cotellic, which was first approved in Switzerland in late August 2015.

Genentech sponsored the Cotellic NDA, having led the compound’s development since midway through the initial phase I clinical trial. Genentech filed its NDA in December 2014; the FDA accepted the filing and granted it Priority Review in February 2015. Separately, Roche filed a Marketing Authorization Application (MAA) with the European Medicines Agency in late 2014, and the Committee for Medicinal Products for Human Use issued a positive opinion for the MAA in September 2015. Roche anticipates a decision from the European Commission by year-end.

“The approval of Cotellic for use in combination with vemurafenib is an important milestone for the melanoma community, and also for Exelixis, as it is the second medicine discovered in our laboratories to receive regulatory approval in the U.S.,” said Michael Morrissey, Ph.D., president and chief executive officer of Exelixis.

The Cotellic approval is based on data from the phase III coBRIM study, which showed Cotellic plus vemurafenib reduced the risk of disease worsening or death (progression-free survival; PFS) by about half in people who received the combination (HR=0.56, 95% CI 0.45-0.70; p<0.001), with a median PFS of 12.3 months for Cotellic plus vemurafenib compared to 7.2 months with vemurafenib alone. An interim analysis also showed the combination of Cotellic and vemurafenib helped people live significantly longer (overall survival) than vemurafenib alone (HR=0.63, 95% CI 0.47-0.85; p=0.0019). The objective response rate (tumor shrinkage) was higher with Cotellic plus vemurafenib compared to vemurafenib alone (70 v. 50%; p<0.001), as was the complete response rate (complete tumor shrinkage, 16 v. 10%).