Immunotherapy Outcomes in Advanced Melanoma in Relation to Age.

Introduction: Older age is a melanoma risk factor. Elderly individuals are likelier to have immunosenescence, which could help melanoma cells escape immune surveillance. Hence, it is believed that elderly people cannot mount a potent immune response to checkpoint inhibitors to eliminate melanoma.

Objectives: To investigate age-related differences in the time to progression, overall survival, and immunotherapy-related adverse events among patients with metastatic melanoma who received checkpoint inhibitors.

Methods: We retrospectively identified patients at our institution between January 2012 and December 2016 with stage IV melanoma who received at least 1 dose of ipilimumab, pembrolizumab, nivolumab, or combined ipilimumab and nivolumab. Demographic, pathologic, and clinical characteristics were obtained. Immune-related response criteria were used to define responses.

Results: Twenty-nine patients were younger than age 65 years and 31 were age 65 years or older. Time to progression was comparable between the age groups (hazard ratio = 0.79, 95% confidence interval = 0.37-1.70, p = 0.46). Overall survival was not significantly different after immunotherapy between groups (hazard ratio = 0.75, 95% confidence interval = 0.31-1.82, p = 0.491). Overall, immunotherapy-related adverse events were comparable between groups, with 62% in younger patients (18/29) and 45% in older patients (14/31 p = 0.19). Of 60 patients, 30 responded to immunotherapy. Nonresponders were more likely than responders to have BRAF-mutated melanomas (16 [53.3%] vs 8 [27.6%]; p = 0.04) and less likely to have immunotherapy-related adverse events (12 [40%] vs 20 [66.7%]; p = 0.04).

Conclusion: Aging does not seem to affect response to checkpoint inhibitors. Elderly patients with metastatic melanoma should be treated similarly to younger patients.