Elsevier

Annals of Oncology

Volume 28, Issue 5, May 2017, Pages 1137-1144
Annals of Oncology

Original articles
Melanoma
Incidence, course, and management of toxicities associated with cobimetinib in combination with vemurafenib in the coBRIM study

https://doi.org/10.1093/annonc/mdx040Get rights and content
Under an Elsevier user license
open archive

Background

In the coBRIM phase III trial, the addition of cobimetinib, an MEK inhibitor, to vemurafenib, a BRAF inhibitor, significantly improved progression-free survival [hazard ratio (HR), 0.58; P<0.0001] and overall survival (HR, 0.70; P=0.005) in advanced BRAF-mutated melanoma. Here, we report on the incidence, course, and management of key adverse events (AEs) in the coBRIM study.

Patients and methods

Patients were randomly assigned 1:1 to receive vemurafenib (960mg twice a day) and either cobimetinib (60mg once a day, 21 days on/7 days off) or placebo. In addition to standard safety evaluations, patients underwent regular ophthalmic, cardiac, and dermatologic surveillance examinations.

Results

Of 495 patients recruited to the study, 493 patients received treatment and constituted the safety population (cobimetinib combined with vemurafenib, 247; vemurafenib, 246). At data cut-off (30 September 2015), median follow-up was 18.5 months. Nearly every patient experienced an AE. In patients who received cobimetinib combined with vemurafenib, the frequency of grade ≥3 AEs was higher than in patients who received vemurafenib alone (75% versus 61%). Most AEs, including grade ≥3 AEs, occurred within the first treatment cycle. After the first cycle (28 days), the incidence of common AEs (rash, diarrhoea, photosensitivity, elevated creatine phosphokinase, serous retinopathy, pyrexia, and liver laboratory abnormalities) decreased substantially over time. Most AEs were managed conservatively by supportive care measures, dose modifications of study treatment, and, occasionally, permanent treatment discontinuation.

Conclusions

These data indicate that most AEs arising from treatment with cobimetinib combined with vemurafenib generally occur early in the treatment course, are mild or moderate and are manageable by patient monitoring, dose modification and supportive care.

ClinicalTrials.gov

NCT01689519.

Key words

cobimetinib
MEK inhibition
melanoma
safety

Cited by (0)

Former employee of Genentech, Inc.