encorafenib + cetuximab + pembrolizumab

This is a **combination regimen** consisting of three agents: the BRAF inhibitor **encorafenib**, the EGFR monoclonal antibody **cetuximab**, and the PD-1 checkpoint inhibitor **pembrolizumab**. Encorafenib acts as a selective inhibitor of the mutant BRAF V600E protein, disrupting the MAPK/ERK signaling pathway in tumor cells. Cetuximab is a chimeric monoclonal antibody that targets the epidermal growth factor receptor (EGFR), blocking downstream signaling that supports tumor growth and survival. Pembrolizumab is a humanized monoclonal antibody against programmed cell death protein 1 (PD-1), promoting anti-tumor immune responses by inhibiting immune checkpoint signaling. This combination is being investigated in the SEAMARK Phase II study for use as a first-line therapy in patients with previously untreated metastatic colorectal cancer (mCRC) harboring both BRAF V600E mutations and microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) phenotypes[1][2][6].