The results could support first-line treatment among patients unable to tolerate other BRAF-MEK inhibitor regimens, or treatment after progression on immunotherapy, they reported.
“Nearly half of patients diagnosed with metastatic melanoma test positive for the BRAF mutation, and there remains a significant need for BRAF-mutant metastatic melanoma treatments,” noted Array BioPharma Chief Medical Officer Victor Sandor, MD.
The encorafenib plus binimetinib regimen “more than doubled” median PFS to nearly 15 months compared with vemurafenib, and is the first targeted therapy to demonstrate a median OS of more than 30 months in a phase 3 trial, according to Dr Sandor.
But in the age of immunotherapy, OS “might not always represent the best measurement to assess efficacy” for investigational melanoma treatments, cautioned Guy Ben-Betzalel, MD, Ella Lemelbaum Institute for Immuno-Oncology, Ramat-Gan, Israel.
“OS data may actually simply represent the responses of those patients to subsequent lines of immunotherapy,” he noted.
Prolonged responses are becoming protracted, so OS data take longer to accrue, Dr Ben-Betzalel noted.
“Extremely durable” responses are possible with anti-PD1/PD-L1 immunotherapy among patients who experience partial or complete tumor responses, he added.
“I believe PFS is a much smarter end point, especially for targeted therapy where we know resistance will develop in most patients,” Dr Ben-Betzalel said.
BRAF plus MEK inhibition will likely prove most useful for maintaining quality of life among patients with metastatic melanoma, he said: “It is, in essence, an excellent palliative tool where immunotherapy has the theoretic potential to be a curative treatment.”