Roche and Exelixis herald a Phase III victory for their melanoma combo

Roche Chief Medical Officer Dr. Sandra Horning

Roche ($RHHBY) and biotech partner Exelixis ($EXEL) said their melanoma-fighting combination therapy met its primary endpoint in Phase III, clearing the way for an FDA application and giving the latter company a boost in its share value.

In a study on 495 patients with a certain mutation of the BRAF gene, a combination of the Exelixis-discovered cobimetinib and Roche's on-the-market Zelboraf helped subjects live significantly longer without disease progression than those treated with Zelboraf alone. The study, called coBRIM, hit its primary goal of progression-free survival, all with a safety profile in keeping with previous studies of the combination, Roche said.

The partners are disclosing only top-line results for now, planning to divulge full details at a future scientific meeting. In the meantime, Roche said it now has the data it needs to support an application with the FDA and other global regulators, though the company has yet to specify a timeline for submissions.

"Despite great progress in our understanding and therapy in recent years, advanced melanoma remains a difficult and deadly disease that requires more treatment options," Chief Medical Officer Dr. Sandra Horning said in a statement. "These encouraging data support the potential combined use of cobimetinib with Zelboraf to block tumor growth longer than Zelboraf alone. We hope this combination therapy will lead to a new option for patients."

Exelixis CEO Michael Morrissey

As for Exelixis, the Phase III success sent the biotech's shares up about 11% in premarket trading on Monday. And the South San Francisco-headquartered company is expecting three more late-stage data readouts this year, CEO Michael Morrissey said, with results due on studies of the proprietary cabozantinib on prostate, thyroid and renal cancers.

Exelixis discovered cobimetinib in-house and advanced it to the IND stage before signing a deal with Roche's Genentech, reaping $40 million up front with the chance to pocket more milestones down the line. The drug, which targets BRAF V600 mutation-positive melanoma, works by shutting down the kinase MEK, a pathway that regulates growth factor receptors and plays a hand in helping tumors proliferate.

- read Roche's statement
- here's Exelixis' release