Pan-Cancer Efficacy of Vemurafenib in <i>BRAF</i> V600-Mutant Non-Melanoma Cancers

<i>BRAF</i> ^V600 mutations occur in a wide range of tumor types, and RAF inhibition has become standard in several of these cancers. Despite this progress, <i>BRAF</i> ^V600 mutations have historically been considered a clear demonstration of tumor lineage context-dependent oncogene addiction, based predominantly on the insensitivity to RAF inhibition in colorectal cancer. However, the true broader activity of RAF inhibition pan-cancer remains incompletely understood. To address this, we conducted a multicohort "basket" study of the BRAF inhibitor vemurafenib in non-melanoma <i>BRAF</i> ^V600 mutation-positive solid tumors. In total, 172 patients with 26 unique cancer types were treated, achieving an overall response rate of 33% and median duration of response of 13 months. Responses were observed in 13 unique cancer types, including historically treatment-refractory tumor types such as cholangiocarcinoma, sarcoma, glioma, neuroendocrine carcinoma, and salivary gland carcinomas. Collectively, these data demonstrate that single-agent BRAF inhibition has broader clinical activity than previously recognized. SIGNIFICANCE: These data suggest that <i>BRAF</i> ^V600 mutations lead to oncogene addiction and are clinically actionable in a broad range of non-melanoma cancers, including tumor types in which RAF inhibition is not currently considered standard of care.<i>See related commentary by Ribas and Lo, p. 640</i>.<i>This article is highlighted in the In This Issue feature, p. 627</i>.