The Evolutionary Landscape of Treatment for BRAF(V600E) Mutant Metastatic Colorectal Cancer

SIMPLE SUMMARY: The BRAF(V600E) mutation accounts for 8–10% of metastatic colorectal cancer (mCRC) patients and it is an established prognostic factor. Median overall survival of this subset of patients is indeed so poor that it is similar to first line PFS of patients without this molecular alteration. An exception is represented by patients displaying concomitant MSI-H status who can benefit from immunotherapy with checkpoint inhibitors (CPIs). Recently, a targeted therapy with the combination of encorafenib and cetuximab provided for the first time a survival gain and thus translation in the clinic, even though acquired resistance limits the possibility of more than an incremental benefit. Many studies exploiting other different strategies are ongoing. In this review we present current therapies specifically headed to BRAF(V600E) mutant mCRC and systematically review ongoing clinical trials identifying different approaches under investigations: targeting MAPK pathway (monotherapy or combinations), targeting MAPK pathway combined with cytotoxic agents, intensive cytotoxic regimen combinations, targeted agents combined with CPIs, oxidative stress induction, and cytotoxic agents combined with antiangiogenic drugs and CPIs. ABSTRACT: The BRAF(V600E) mutation is found in 8–10% of metastatic colorectal cancer (mCRC) patients and it is recognized as a poor prognostic factor with a median overall survival inferior to 20 months. At present, besides immune checkpoint inhibitors (CPIs) for those tumors with concomitant MSI-H status, recommended treatment options include cytotoxic chemotherapy + anti-VEGF in the first line setting, and a combination of EGFR and a BRAF inhibitor (cetuximab plus encorafenib) in second line. However, even with the latter targeted approach, acquired resistance limits the possibility of more than an incremental benefit and survival is still dismal. In this review, we discuss current treatment options for this subset of patients and perform a systematic review of ongoing clinical trials. Overall, we identified six emerging strategies: targeting MAPK pathway (monotherapy or combinations), targeting MAPK pathway combined with cytotoxic agents, intensive cytotoxic regimen combinations, targeted agents combined with CPIs, oxidative stress induction, and cytotoxic agents combined with antiangiogenic drugs and CPIs. In the future, the integration of new therapeutic strategies targeting key players in the BRAF(V600E) oncogenic pathways with current treatment approach based on cytotoxic chemotherapy and surgery is likely to redefine the treatment landscape of these CRC patients.