Background: Since the mCRPC treatment landscape is evolving, we examined real-world use and outcomes of sipuleucel-T (sip-T) and oral agents (abiraterone acetate and enzalutamide) in men with mCRPC. Methods: Using Medicare FFS Identifiable Research data, we identified mCRPC men with a qualifying prostate cancer diagnosis (ICD-9 185, ICD-10 C-61) and an initial treatment claim (abiraterone, cabazitaxel, docetaxel, enzalutamide, radium 223, sip-T) in 2014. Continuous Part A, B, and D eligibility and no HMO enrollment was required through 2017 or until death. mCRPC index date is the date of a mCRPC therapeutic claim. Using 4 groups (sip-T first line, oral first line, sip-T any line, and oral any line [no sip-T]), survival was estimated using Kaplan-Meier methods (unadjusted). Hazard ratios (HR) were estimated using Cox’s proportional hazards regression modeling. Results: During 2014, 14,482 eligible men had mCRPC drug claims. We studied 6,853 naïve mCRPC men with no treatment claim in the prior 12 months. Over 150 permutations of anti-cancer agents were identified. See table for patient characteristics. Sip-T was used 2+ line in 4.5% of men receiving orals 1st. Median overall survival was longer for men who received sip-T, regardless if used 1st line (35 mo) or in any line (35 mo), compared with oral 1st line use (21 mo) or an oral any time without sip-T (21 mo). Similar survival was seen after adjusting for baseline opioid use. While most received sip-T as 1st line, survival rates were higher in men receiving sip-T in any line (48%) compared to men who never received any sip-T (29%). Conclusions: In this analysis, sip-T use was associated with a 45% reduction in risk of death and 14 mo survival benefit in the Medicare FFS population regardless of when used. Real-world analyses like this provide insight into how to optimize sip-T use to treat prostate cancer.

* Never received sip-T