BRAF V600E + PD-1 (combination regimen)

Class

BRAF V600E inhibitor (HLX208) combined with anti-PD-1 monoclonal antibody (HLX10/serplulimab)

Pathway

MAPK pathway blockade combined with PD-1 immune checkpoint blockade

BRAF is a kinase in the MAPK/ERK signaling pathway that normally transmits growth signals from cell-surface receptors to the nucleus, controlling proliferation and survival. In many cancers, a mutation called V600E locks BRAF into a permanently active state, driving continuous proliferative signaling independent of external cues. Small-molecule BRAF inhibitors selectively block this mutant kinase, slowing tumor growth. Separately, PD-1 is an inhibitory receptor on T cells that, when engaged by its ligands, dampens immune attack; tumors often exploit this checkpoint to evade destruction. Antibodies blocking PD-1 restore T-cell activity against the tumor. Combining a BRAF V600E inhibitor with a PD-1 blocking antibody pairs two distinct anticancer strategies: direct suppression of oncogenic proliferative signaling and reactivation of antitumor immunity. The rationale is that inhibiting mutant BRAF can also alter the tumor microenvironment in ways that make it more visible and vulnerable to immune attack, potentially making checkpoint blockade more effective, while immune-mediated killing may provide more durable control than kinase inhibition alone, which cancers often eventually circumvent. This combination approach is broadly relevant to melanoma and other tumors driven by the BRAF V600E mutation.