Increased risk of immune-related hepatitis among adolescent and young adults (AYAs) with melanoma during immunotherapy with checkpoint inhibitors (ICIs).

Abstract

9584 Background: Melanoma is the second most common malignancy affecting AYA patients after lymphoma. Nevertheless, AYA melanoma does constitute a minority of all melanoma cases. Additionally, the AYA population is not well represented in prospective clinical trials, including immunotherapy trials. While previous research has demonstrated the efficacy of ICIs across age groups, it remains unclear if toxicity profiles will be similar. In the general population, age-related changes in the immune milieu result in differential incidences of autoimmune diseases by age. This study aims to compare the toxicity profile between a cohort of AYA melanoma versus elderly melanoma patients receiving ICI therapy. Methods: In this single NCCN institutional study, electronic medical records of melanoma patients treated with ICIs between 01/2007-01/2019 were reviewed. Subjects receiving concurrent investigational agents or chemotherapy were excluded. The AYA cohort included those aged 15-40 years. The elderly cohort included those aged ≥65 years. Adverse events were coded according to CTC-AE version 5.0. Multivariable logistic regression analyses were performed. Results: Analyses included 184 treatment courses. In the AYA cohort (N = 57), median age at ICI initiation was 28.8 years (range: 17.9-39.3). In the Elderly cohort (N = 127), median age at ICI initiation was 72.3 years. More AYA patients (28.1% AYA vs. 7.9% Elderly) received ICI combination regimens. The most common adverse events amongst both cohorts were transaminitis (23.4%), rashes (49.5%), and diarrhea/colitis (20%). Incidences of pneumonitis, colitis, hypothyroidism, and hypophysitis did not differ significantly between cohorts. However, the AYA cohort experienced a higher incidence of transaminitis (38.6% AYA vs. 16.5% Elderly, p =0.001 ) and increased occurrence of treatment related hospitalization (26.3% AYA vs. 7.1% Elderly, p <0.001 ). Moreover, a higher proportion of severe grade ≥3 transaminitis occurred in the AYA group (27.3% AYA vs. 9.5% Elderly, p =0.004). While occurrence of transaminitis was significantly associated with combination ICIs, the association between AYA status and transaminitis remained significant after adjusting for ICI regimen (OR 2.75, 95% CI: 1.3-5.8). There was a trend toward shorter time to transaminitis onset among the AYA than Elderly cohort (median 53.0 vs. 74.5 days [non-parametric p= 0.28]). To date, median survival has not been reached in both groups ( p= 0.09). Conclusions: In this large cohort of AYA melanoma patients treated with ICI, we found a significantly higher incidence of immune-related transaminitis than in the Elderly cohort. Other immune-related AEs were comparable between cohorts. This finding was independent of ICI regimen. Further investigation will be needed to understand these differences between the AYA and Elderly cohorts.