Immune-related adverse events and survival in elderly patients with melanoma treated with ipilimumab.

3047 Background: Immune-related adverse events (irAE) encompass wide-ranging toxicities in patients (pts) taking Ipilimumab. Experienced by many pts on Ipilimumab, they occasionally result in death. As irAE could be indicative of an enhanced immune response to therapy, pts developing these events potentially experience improved therapeutic response and survival. We evaluated the toxicity patterns of irAE in older pts with melanoma receiving Ipilimumab, and the association of irAE with their overall survival (OS). Methods: We identified melanoma pts 65 years or older, treated with Ipilimumab using the Surveillance Epidemiology and End Results (SEER) and Texas Cancer Registry (TCR) linked with Medicare data between 3/2011 and 12/2013. We defined 44 types of irAE based on 228 ICD-9 diagnosis codes; irAE had to occur within 3 months of last treatment and include one or more diagnosis codes, which could not be present within a 6-month window before treatment. We classified pts with irAE as severe if they had a related hospitalization or death within 2 weeks of the claim. We used log rank and multivariable Cox regression to analyze OS. Results: We identified 858 pts with mean age at diagnosis 69.1 years and mean age at treatment 74.8 years. More than half of pts (63.3%) had a Charlson Comorbidity Index of 0. Pts received a median of 3 treatment courses. 510 (60%) pts experienced irAE with 178 pts (20.7%) experiencing severe irAE. The most frequent irAE were colitis (17.5%), hypothyroidism (10.5%), dermatitis (5.4%) and hypophysitis (3.7%). Those with non-severe irAE had improved OS compared with no irAE or severe irAE with median survival years being 1.1, 0.9, and 0.6, respectively (p < 0.001). In the multivariable analysis, severe irAE pts were 28% more likely to die compared to pts with no irAE (p = 0.04). Conclusions: In this retrospective study our findings suggest that the incidence of irAE occurs in elderly melanoma pts at comparable rates to all melanoma pts treated with Ipilimumab. Hypothyroidism occurred more frequently than what has been reported in clinical trials. Pts with non-severe irAE had improved OS compared to pts with no irAE. Pts with severe irAE appeared to have the highest risk of death.