Patients with a particular form of melanoma taking a combination of Roche’s cobimetinib (being developed with Exelixis) and Zelboraf (vemurafenib) lived significantly longer without their disease worsening than those taking the latter alone, trial results show.

While keeping specific data under wraps for now, the Swiss drug giant said that the international, randomised, double-blind, Phase III CoBRIM study met its primary endpoint in showing improved progression-free survival.

The trial, which pitted the two regimens against each other in 495 patients with unresectable, locally-advanced, previously untreated metastatic melanoma carrying a mutation called BRAF V600, “support the potential combined use of cobimetinib with Zelboraf to block tumour growth longer than Zelboraf alone,” noted Sandra Horning, Chief Medical Officer and Head of Global Product Development.

Dual attack

The two-pronged approach sees cobimetinib selectively block the activity of the protein MEK 2, which is involved in regulating cell division and survival, and Zelboraf bind to mutant BRAF, another protein on the pathway, to interrupt abnormal signalling that fuel tumour growth.

More than 232,000 people worldwide are currently diagnosed with melanoma each year, of which around half will be carrying the BRAF mutation.

Data from the trial will be presented at an upcoming medical meeting, said Roche.