Atezolizumab/Vemurafenib Combo Shows Clinical Activity in BRAF+ Melanoma

Source: OncLive, January 2016

The combination of atezolizumab (MPDL3280A) and vemurafenib (Zelboraf) yielded durable responses in patients with previously untreated BRAF V600–mutated metastatic melanoma in an ongoing phase Ib study.1

Atezolizumab, an investigational PD-L1 inhibitor, and vemurafenib, a BRAF-targeted agent, produced an objective response rate (ORR) of 76% (95% CI, 50.1%–93.2%). This included 3 complete responses (CR) and 10 partial responses (PR) among the 17 patients evaluable at the time of data collection.

“The targeted therapy has a great initial response rate and a great palliative benefit, but a not so great long-term durable benefit. The immunotherapy has a low initial response rate, but the ability to have a long-term durability,” said Omid Hamid, MD, who presented the phase Ib data at the Society for Melanoma Research 2015 International Congress. “The study is still accruing, but as we’ve brought the cohorts forward, we are seeing higher response rates and durable responses.”

In the multicenter, open-label, dose-escalation study, patients received atezolizumab combined with vemurafenib concurrently (n = 3) or after a run-in period with vemurafenib alone for 56 days (n = 8) or 28 days (n = 6). Atezolizumab was administered intravenously every 3 weeks at 20 mg/kg or 15 mg/kg or 1200 mg fixed. Vemurafenib was given twice daily at 960 mg during the run-in period and at 720 mg during the combination.