Work

First-line ipilimumab plus nivolumab in advanced merkel cell carcinoma: a meta-analysis of prospective trials and real-world validation cohort

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: BACKGROUND: Advanced Merkel cell carcinoma (MCC) has a high response rate to immune checkpoint blockade (ICB). While early phase studies have demonstrated activity of dual ICB with anti-PD-1 plus anti-CTLA-4 agents in both the first- and second-line settings, the role of combination therapy as a first-line approach remains controversial. METHODS: We conducted a systematic review and meta-analysis to summarize the current evidence of first-line ICB therapy in MCC and to compare the pooled objective response rate (ORR) between combination ICB and monotherapy. Pooled ORRs were estimated using fixed-effects meta-analyses, and these results were statistically compared between combination ICB and monotherapy. In addition to the meta-analysis and as real-world validation, we performed a retrospective chart review of MCC patients treated with first-line combination ICB at a single referral center. RESULTS: In the meta-analysis, the pooled ORR of ipilimumab plus nivolumab was significantly higher than that of either anti-PD(L)1 monotherapy when considering all anti-PD-1 and anti-PD-L1 agents (81.0% vs. 49.6%, p = 0.0001) as well as monotherapy when restricted to anti-PD-1 agents (81.0% vs. 57.0%, p = 0.0043). Concordant with pooled trial findings, we identified eight patients treated off protocol with first-line combination ICB at our institution, with seven (87.5%) achieving objective response. DISCUSSION: Based on meta-analysis of clinical trial data, first-line treatment of advanced Merkel cell carcinoma with ipilimumab plus nivolumab results in a higher objective response rate compared to monotherapy. The clinical decision to select combination therapy over monotherapy must weigh this response rate benefit with the unknown survival benefit and higher toxicity.

Source: Cancer Immunology Immunotherapy

DOI: 10.1007/s00262-026-04313-2