Long-Term Survival in Patients With Advanced Melanoma

IMPORTANCE Long-term survival data from clinical trials show that survival curves of patients with advanced melanoma treated with immune checkpoint inhibitors (ICIs) gradually reach a plateau, suggesting that patients have a chance of achieving long-term survival. OBJECTIVE To investigate long-term survival in patients with advanced melanoma treated with ICIs outside clinical trials. DESIGN, SETTING, AND PARTICIPANTS Cohort study using prospectively collected data from the nationwide Dutch Melanoma Treatment Registry, including patients in the Netherlands with advanced melanoma treated with first-line ICIs from 2012 to 2019. Data were analyzed from January to September 2023. EXPOSURES Patients were treated with first-line ipilimumab-nivolumab, antibodies that target programmed cell death (anti–PD-1), or ipilimumab. MAIN OUTCOMES AND MEASURES Progression-free survival (PFS) and melanoma-specific survival were analyzed, and a Cox proportional hazards model was used to investigate factors associated with PFS after reaching partial response (PR) or complete response (CR). RESULTS A total of 2490 patients treated with first-line ICIs were included (median IQR age, 65.0 55.3-73.0 years; 1561 male patients 62.7%). Most patients had an Eastern Cooperative Oncology Group Performance Status of 1 or lower (2202 patients 88.5%) and normal lactate dehydrogenase levels (1715 patients 68.9%). PFS for all patients was 23.4% (95% CI, 21.7%-25.2%) after 3 years and 19.7% (95% CI, 18.0%-21.4%) after 5 years. Overall survival for all patients was 44.0% (95% CI, 42.1%-46.1%) after 3 years and 35.9% (95% CI, 33.9%-38.0%) after 5 years. Patients with metastases in 3 or more organ sites had a significantly higher hazard of progression after reaching PR or CR (adjusted hazard ratio, 1.37; 95% CI, 1.11-1.69). CONCLUSIONS AND RELEVANCE This cohort study of patients with advanced melanoma treated with ICIs in clinical practice showed that their survival reached a plateau, comparable with patients participating in clinical trials. These findings can be used in daily clinical practice to guide long-term surveillance strategies and inform both physicians and patients regarding long-term treatment outcomes.