Real-World Outcomes of Nivolumab and Ipilimumab in Metastatic Melanoma as Third Line and Beyond.

Nivolumab plus ipilimumab has demonstrated activity after anti-PD-1 failure in advanced melanoma, but its effectiveness in later lines and as rechallenge remains unclear. We aimed to characterize outcomes of nivolumab/ipilimumab administered in the third line or beyond. Using the Danish Metastatic Melanoma Database (DAMMED), we identified patients with metastatic melanoma (excluding uveal melanoma) treated with nivolumab/ipilimumab after at least two prior lines of therapy, including adjuvant treatment, between 2017 and 2024. Baseline characteristics, prior treatments, and clinical outcomes were collected. Seventy-three patients were included (median age 57.8 years), of whom 47.9% had brain metastases. Most had progressed on anti-PD-1-based therapy (93.2%); 32.9% had prior exposure to anti-CTLA-4, and 84.9% had received BRAF/MEK inhibitors. Nivolumab/ipilimumab was administered as third-line therapy in 71.2%. After a median follow-up of 27.6 months, the overall response rate was 23.3% (12.5% with prior anti-CTLA-4 exposure vs. 28.6% without). Median duration of response was 19.4 months (95% CI, 14.5-NR). Median PFS was 2.7 months (95% CI, 2.4-5.7) and median OS was 9.6 months (95% CI, 6.5-20.1). In conclusion, in heavily pretreated melanoma, nivolumab/ipilimumab induces durable responses in a minority of patients, with reduced efficacy after prior anti-CTLA-4 exposure.