Safety and Efficacy of Encorafenib, Binimetinib, and Cetuximab for BRAFV600E-Mutant Metastatic Colorectal Cancer: Results of the Japanese Expanded Access Program

Abstract

Background: The phase 3 BEACON CRC study demonstrated the survival benefits of encorafenib and cetuximab, with or without binimetinib (the BEACON triplet or doublet regimen), for BRAF^V600E-mutant metastatic colorectal cancer (mCRC). This expanded access program (EAP) and subsequent follow-up study assessed the efficacy and safety of the BEACON triplet regimen in Japanese patients with BRAF^V600E-mutant mCRC.

Materials and methods: The EAP was an open-label, single-arm study including Japanese patients with BRAF^V600E-mutant mCRC whose disease progressed after 1 to 2 prior regimens. The patients received the BEACON triplet regimen with 28-day cycles. The subsequent follow-up study assessed the survival outcomes following EAP completion. Safety was assessed only during the EAP.

Results: Among the 86 enrolled patients, 81 received the BEACON triplet regimen. The objective response rate and median progression-free survival were 27.6% (95% confidence interval [CI], 18.0%-39.1%) and 5.26 (95% CI, 4.14-5.52) months, respectively. Grade 3 to 4 adverse events and treatment-related adverse events occurred in 43.2% and 28.4% of patients, respectively. No new safety signals were observed during the EAP. Among 58 patients with confirmed survival at EAP completion, 57 were included in the follow-up study. With a median observation period of 9.17 months through the EAP and follow-up study, the median overall survival was 10.38 (95% CI, 9.00-16.16) months.

Conclusion: The efficacy and safety of the BEACON triplet regimen in Japanese patients with BRAF^V600E-mutant mCRC were consistent with those reported in the BEACON CRC trial, supporting its use as a standard treatment for pretreated patients with BRAF^V600E-mutant mCRC.

Keywords: BRAF inihibitor; BRAF(V600E)mutation; EAP; MEK inhibitor; mCRC.