Toxicity, response, and survival in older adults with metastatic melanoma treated with checkpoint inhibitors.

Abstract

9544 Background: Checkpoint inhibitors have strongly improved survival of patients with metastatic melanoma. Trials suggest no differences in outcomes between older and younger patients, but only relatively young patients with a good performance status were included in these trials. The aim of this study was to describe treatment patterns and outcomes of older adults with metastatic melanoma, and to identify predictors of outcome. Methods: We included all patients aged ≥65 years with metastatic melanoma between 2013 and 2020 from the Dutch Melanoma Treatment registry (DMTR), in which detailed information on patients, treatments and outcomes is available. We assessed predictors of grade ≥3 toxicity and 6-months response using logistic regression models, and melanoma-specific and overall survival using Cox regression models. Additionally, we described reasons for hospital admissions and treatment discontinuation. Results: A total of 2216 patients were included. Grade ≥3 toxicity did not increase with age, comorbidity or WHO performance status, in patients treated with monotherapy (anti-PD1 or ipilimumab) or combination treatment. However, patients aged ≥75 were admitted more frequently and discontinued treatment due to toxicity more often. Six months-response rates were similar to previous randomized trials (40.3% and 43.6% in patients aged 65-75 and ≥75 respectively for anti-PD1 treatment) and were not affected by age or comorbidity. Melanoma-specific survival was not affected by age or comorbidity, but age, comorbidity and WHO performance status were associated with overall survival in multivariate analyses. Conclusions: Toxicity, response and melanoma-specific survival were not associated with age or comorbidity status. Treatment with immunotherapy should therefore not be omitted solely based on age or comorbidity. However, the impact of grade I-II toxicity in older patients deserves further study as older patients discontinue treatment more frequently and receive less treatment cycles.[Table: see text]