Association of age with survival in older patients with cutaneous melanoma treated with immune checkpoint inhibitors.

INTRODUCTION: Several types of immune checkpoint inhibitors (ICIs) are approved to treat advanced melanoma, but their effectiveness has not been compared in older patients treated outside of a clinical trial. Moreover, evidence suggests that a patient's response to ICI therapy may vary by age and type of ICI. The purpose of this study was to compare survival by ICI type in older patients with melanoma and to investigate treatment effect modification by age. MATERIALS AND METHODS: Using the SEER-Medicare database, we identified patients with cutaneous melanoma (2012-2015) treated with an ICI (CTLA-4, PD-1, or combination CTLA-4 + PD-1 inhibitors). Cox proportional hazards regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for ICI types. We used an interaction term and stratified models to test for treatment effect modification by age. RESULTS: Of the 1435 patients included in our analysis, 790 (55.1%) received CTLA-4 inhibitors, 512 (35.7%) received PD-1 inhibitors, and 133 (9.3%) were treated with combination ICIs. Median survival ranged from 13.4 months (95%CI: 10.7-16.3) for CTLA-4 inhibitors to 23.5 months (95%CI: 16.2-30.0) for combination ICIs. In multivariable models, the risk of death was lower with PD-1 inhibitors compared to CTLA-4 inhibitors (HR = 0.78, 95%CI: 0.68-0.89). An age*ICI type interaction term was significant (p < 0.001), and survival gains were greater the older age group (≥80) compared to the younger group (65-79). DISCUSSION: In a population-based setting, we identified important differences in survival by ICI type in older patients with melanoma treated with ICIs, with prolonged survival associated with PD-1 inhibitors compared to CTLA-4 inhibitors.

Immune checkpoint inhibitors retain effectiveness in older patients with cutaneous metastatic melanoma.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have dramatically changed the treatment landscape for advanced melanoma, but their use in older patients remains understudied. An age-related decline in immune function is of concern when treating older patients because host immune factors can influence clinical outcomes with immunotherapy. Therefore, we aimed to evaluate the effectiveness of ICIs in patients 65 years and older. METHODS: Using the SEER-Medicare data, we evaluated survival by first systemic treatment type in a retrospective cohort study of patients aged 65 years and older who were diagnosed with stage IV cutaneous melanoma between 2012 and 2015. Cox proportional hazards regression was used to estimate hazard ratios (HR) and their corresponding 95% confidence intervals. RESULTS: A total of 541 patients were included in this study. Median survival differed significantly between groups (p < 0.0001) and was longest in patients treated with PD-1 inhibitors (34.0 months), followed by CTLA-4 inhibitors (16.8 months), targeted therapy (9.7 months), chemotherapy (7.1 months), and no systemic therapy (3.6 months). The ICI survival benefit persisted after adjusting for age, sex, comorbidities, M stage, the presence of brain metastases, and evaluation at an NCI-designated cancer center. Hazard ratios comparing ICIs to no systemic therapy were 0.35 (95% CI: 0.24-0.52) for PD-1 inhibitors and 0.48 (95% CI: 0.37-0.63) for CTLA-4 inhibitors. We did not observe a difference in ICI effectiveness by age group (65-74 vs ≥75). CONCLUSIONS: In a nationally representative cohort of patients with advanced melanoma, ICI therapy delivered in a real world setting significantly improved survival in patients aged 65 years and older.