Encorafenib for Colorectal Caner

On 1 January 2022, the Pharmaceutical Benefits Scheme (PBS) listing for encorafenib was expanded to include metastatic colorectal cancer. This listing requires therapy to be in combination with cetuximab, and patients must have BRAF V600 variant positive disease. Up to 15% of patients with metastatic colorectal cancer have a BRAF mutation, and this is associated with a poorer outcome.

The BEACON-CRC trial evaluated the safety and efficacy of encorafenib and cetuximab. Patients were randomly assigned to receive triple therapy (encorafenib, binimetinib, plus cetuximab)*, dual therapy (encorafenib plus cetuximab), or control (investigators’ choice of cetuximab plus irinotecan or cetuximab plus FOLFIRI [folinic acid, fluorouracil, and irinotecan]). The median overall survival was 9.0 months for triple therapy, 8.4 months for dual therapy, and 5.4 months for the control group. Analysis of this trial demonstrates that dual therapy provides a clinically relevant benefit with regards to overall survival and objective response rate compared to the control group.

Some of the most commonly reported adverse events in the dual therapy group included gastrointestinal and skin-related events, such as diarrhoea (33%), nausea (34%), vomiting (21%), and acneiform dermatitis (29%). Adverse events of grade 3 or higher occurred in 50% of patients in the double therapy group and 61% of the control group.

*Colorectal cancer is not currently a registered indication for binimetinib in Australia.