Genentech, Exelixis score another PhIII success for cobimetinib

Genentech has added another piece of the trial puzzle for its MEK inhibitor cobimetinib. The big Roche ($RHHBY) subsidiary's partner Exelixis ($EXEL) announced early Tuesday that the drug combined with Zelboraf hit the mark in a Phase III study, offering a statistically significant overall survival benefit among advanced melanoma patients carrying a BRAF V600 mutation.

That leaves the drug on track for near-term approvals in the U.S. as well as Europe, where the CHMP recently adopted a favorable opinion on its approval. The PDUFA date for cobimetinib--to be sold as Cotellic--rolls around next month.

Exelixis' stock jumped 6% on the news Tuesday morning, which was strictly top-line only. Actual data will be released at an upcoming conference. 

Back in May Exelixis announced a progression-free survival rate of 12.3 months for their combo, compared to 7.2 months for Zelboraf alone--a marker that would generally indicate a likely approval awaits Exelixis and Roche. At least one analyst had forecast peak potential sales at $790 million.

The last few months have offered considerable relief to South San Francisco-based Exelixis, which was forced to restructure last year--laying off 70% of its staff--after its big pivotal study for cabozantinib failed for prostate cancer. Last July shareholders rallied around the news of a Phase III success for the drug in kidney cancer, though that announcement was quickly overshadowed by Bristol-Myers' ($BMY) success in the same field for its closely watched checkpoint inhibitor Opdivo.

Exelixis CEO Michael Morrissey

Exelixis exercised its U.S. co-promotion rights for cobimetinib two years ago and says it is prepared to field up to 25% of the sales force for the therapy.

"We continue to work with our partners at Genentech in preparation for the potential U.S. approval and launch of cobimetinib to deliver this important potential treatment option to patients, physicians and caregivers in the United States as quickly as possible," noted Exelixis CEO Michael Morrissey in a statement.

- here's the release

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