Anti-PD-1 Combinations: Triplets and Beyond

The advent of anti-PD-1 therapy has transformed the treatment paradigm of advanced melanoma, enabling durable responses in a proportion of patients. However, the impact of both primary and acquired resistance remains a significant barrier to sustained disease control. This review explores the biological rationale and clinical progress of anti-PD-1 based combination strategies, with a particular emphasis on emerging triplet regimens and next-generation immunotherapeutic approaches designed to extend survival and overcome resistance.

While dual checkpoint inhibition (anti-PD-1 plus anti-CTLA-4 or anti-LAG-3) has improved clinical outcomes, further therapeutic advances are needed to expand the depth and durability of responses. Triplet combinations have shown promising activity in early-phase trials, with acceptable safety profiles. Promising triplet strategies currently under investigation include combinations of BRAF and MEK inhibitors with anti-PD-1 agents in BRAF-mutant melanoma, as well as regimens pairing anti-PD-1 therapy with emerging immunomodulatory agents. Biomarkers and disease control prior to infusion appear to be key determinants of outcome. Anti-PD-1-based triplet therapies represent a promising frontier in melanoma treatment. Future trials should define optimal combinations, patient selection, and therapeutic sequencing to maximize benefit and minimize toxicity.