Exelixis has been informed by partner Genentech, a member of the Roche Group, that, in order to accommodate its review of a supplemental data submission, the FDA has extended the Prescription Drug User Fee Act (PDUFA) action date for its review of Genentech's NDA for cobimetinib by the standard extension period of three months, from Aug. 11 to Nov. 11.

FDA extended its review after Genentech submitted, at FDA request, additional data from coBRIM, the phase III registrational trial of cobimetinib and vemurafenib in patients with BRAF V600 mutation-positive advanced melanoma.

Exelixis discovered cobimetinib, a selective inhibitor of MEK, internally and advanced the compound to IND status. In late 2006, Exelixis entered into a collaboration agreement with Genentech, under which Exelixis received initial upfront and milestone payments in connection with signing the agreement and submitting the IND. Exelixis was responsible for development of cobimetinib through the determination of the maximum tolerated dose in phase I, at which point Genentech exercised its option to further develop the compound.

In November 2013, Exelixis exercised its option to co-promote cobimetinib, if approved, in the US. Exelixis is entitled to an initial equal share of U.S. profits and losses, which will decrease as sales increase, and will share equally in the U.S. marketing and commercialization costs. Exelixis is eligible to receive royalties on any sales of the product outside the U.S.