LAUSR

e21002 Background: The use of CPIs among patients (pts) with metastatic MCC, a rare and aggressive skin cancer, has increased since the US FDA approval of avelumab and the National Cancer Comprehensive Network (NCCN) recommendation of CPIs in 2017. Given the growing interest in understanding real-world clinical and economic outcomes associated with CPI use, this study assessed time to treatment failure (TTF), overall survival (OS), healthcare resource utilization (HRU), and costs among MCC pts receiving NCCN-recommended 1L regimens including CPIs and CT in the VHA. Methods: This is a retrospective analysis of pts with newly-diagnosed MCC who initiated 1L treatment between October 2013 and January 2018 (index date = 1L therapy start date) and had continuous enrollment from ≥6 months pre-initial MCC diagnosis date until ≥2 months post-index date (follow-up). The index date to earliest of death or subsequent line of therapy start was used as a proxy for TTF. TTF and OS were estimated using Kaplan Meier method. All-cause HRU and costs (2018 USD) per patient per month (PPPM) were evaluated during TTF or until end of follow-up, whichever occurred first. Results: Of 120 MCC pts (72% pre-2017) initiating 1L therapy, 62% received NCCN-recommended regimens, including 17% and 45% treated with CPIs and CTs. Pts receiving CPIs were on average older with higher baseline comorbidity burden. The clinical and economic outcomes of these two pt groups are summarized in the table below. Conclusions: The current descriptive non-comparative analyses provide new information on the trends in clinical and economic outcomes of MCC pts treated in the VHA. Despite higher costs, the utilization of newly-approved CPIs in 1L setting showed delayed treatment failure and reduced all-cause HRU vs. CTs. These findings require further validation in studies with larger patient cohorts and longer follow-up. [Table: see text]