Real-World Outcomes of Immune Checkpoint Inhibitors in Melanoma, Including Acral and Mucosal Subtypes: A Retrospective Cohort Study From a Latin American Center.

Abstract

Background: Real-world evidence on immune checkpoint inhibitors (ICIs) in Latin American patients with melanoma remains limited, particularly for acral and mucosal subtypes. We evaluated survival, radiologic response, immune-related adverse events (irAEs), and exploratory factors associated with outcomes in a Colombian cohort.

Methods: This single-center retrospective cohort included consecutive patients with histologically confirmed melanoma who received ≥ 1 ICI dose between February 2017 and November 2022. Patients were classified as adjuvant- or palliative-intent. rwOS and irAEs were assessed in the overall cohort; rwDFS in the adjuvant-intent cohort; and rwPFS and best radiologic response in the palliative-intent cohort. Survival was estimated using Kaplan-Meier methods, with median follow-up calculated by reverse Kaplan-Meier. Primary Cox proportional hazards analyses of rwPFS and rwOS were restricted to the palliative-intent cohort.

Results: Fifty-seven patients were included: 20 received adjuvant- and 37 palliative-intent therapy. Median age was 65 years (IQR, 54-76); acral and mucosal melanoma accounted for 26 (45.6%) and 11 (19.3%) cases, respectively. Median follow-up was 32.3 months (95% CI, 25.9-42.3). In the adjuvant-intent cohort, median rwDFS and rwOS were 23.3 months (95% CI, 4.8-not reached) and 33.0 months (95% CI, 30.1-not reached), respectively. In the palliative-intent cohort, median rwPFS and rwOS were 8.5 months (95% CI, 6.0-24.1) and 26.0 months (95% CI, 17.9-not reached), respectively. Among 31 response-evaluable patients, ORR was 38.7% (95% CI, 23.7-56.2) and DCR was 54.8% (95% CI, 37.8-70.8). IrAEs were documented in 31 patients (54.4%); five had Grade 3 events, and no Grade 4 or five irAEs were documented. In adjusted models, ECOG performance status and melanoma subtype were not significantly associated with rwPFS or rwOS.

Conclusions: ICIs demonstrated antitumor activity in this Colombian real-world cohort, including patients with acral and mucosal melanoma, although survival estimates were numerically lower than those reported in selected pivotal trials. Documented toxicity was predominantly low grade. Exploratory analyses suggested more favorable outcomes in patients with conventional cutaneous melanoma.