Response rate and long-term survival in patients with advanced melanoma: data from the prospective cohort study gem-1801.

[PURPOSE] Anti-PD-1-based immunotherapy and targeted therapies (TT) are the current standard of care for patients with advanced melanoma. However, some patients die in less than a year from diagnosis and others become long-survivors. An accurate description of systemic treatments and patients' characteristics of long-term survivors are needed to guide treatment decisions in clinical practice.

[METHODS] GEM-1801 is a multi-cohort prospective study from the Spanish Multidisciplinary Melanoma Group that includes patients with resectable stage III or unresectable stage III/IV melanoma. Patients surviving at least 5 years and patients surviving less than 1 year since diagnosis were selected. Baseline characteristics and first and second-line systemic treatments are described and compared between groups.

[RESULTS] From Aug 2018 to Dec 2023, 60 patients with long-term survival and 216 patients with short-term survival were included. Long-term survivors received immunotherapy (65%), including anti-PD-1 in 86% and combination of an anti-PD-1 and anti-CTLA-4 in 14%; and TT (35%). The Objective Response Rate (ORR) was 76% for anti-PD-1, 80% for combination immunotherapy and 83% for TT. Short-term survivors received immunotherapy (58%), including anti-PD-1 (70%), anti-CTLA-4 (1%), and anti-PD-1 plus anti-CTLA-4 (29%); TT (36%); and chemotherapy (2%). ORR was 7% for anti-PD-1, 0% for anti-CTLA-4, 14% for combination immunotherapy, 53% for TT and 0% for chemotherapy.

[CONCLUSIONS] Response to first or second-line systemic treatment may be a surrogate for long-term survival patients with advanced melanoma.

[CLINICAL TRIAL IDENTIFICATION] Clinicaltrials.gov: NCT03605771.