Cobimetinib in combination with atezolizumab was active and associated with a median progression-free survival of 15.7 months among patients with BRAF wild-type non-ocular melanoma, according to data presented at the Society for Melanoma Research 2016 Congress in Boston, Massachusetts.1

In the melanoma cohort of a phase 1b trial of cobimetinib and atezolizumab, investigators enrolled 22 patients with metastatic disease, including 20 patients with non-ocular melanoma. Of those, 10 had BRAF V600 mutation-positive disease and 10 had BRAF wild-type disease.

Results showed that 45% of the 20 patients with non-ocular melanoma achieved a partial response, including 5 with BRAF wild-type melanoma. Median duration of response was 14.9 months and median progression-free survival was 12 months overall. Median overall survival has not yet been reached.

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Subgroup analysis demonstrated that median progression-free survival was 15.7 months among those with BRAF wild-type melanoma and 11.9 months among those with BRAF mutation-positive disease.

Combination therapy was generally well tolerated, with 59% of patients reporting treatment-related grade 3 to 4 adverse events but no grade 5 toxicities.

Based on these findings, Genentech plans to evaluate cobimetinib plus atezolizumab compared with a PD-1 inhibitor among treatment-naive patients with BRAF wild-type advanced melanoma in a phase 3 trial.

RELATED: For First-line Therapy of BRAF-mutant Melanoma, PD-1 Inhibitors May Be Preferred

Cobimetinib is a kinase inhibitor approved for the treatment of patients with unresectable or metastatic melanoma with a BRAF V600E or V600K mutation, in combination with vemurafenib. Atezolizumab is a programmed death-ligand 1 (PD-L1) blocking antibody indicated for advanced bladder cancer and non-small cell lung cancer.


  1. Exelixis announces presentation of cobimetinib combination therapy data at the Society for Melanoma Research 2016 Congress that support Genentech’s planned phase 3 pivotal trials. Exelixis website. Updated November 7, 2016. Accessed November 7, 2016.