Background: Multiple phase III trials have proven that Abi and Doc both improve overall survival (OS) in men with mHSPC. No randomized trials have compared the two approaches. Methods: We conducted a retrospective, observational study to compare OS in de novo M1 men, treated with Abi vs. Doc using patient-level data from the Flatiron health EHR-derived de-identified database. We also compared this real-world OS to trial level data using extracted data points along the OS curves from CHAARTED and LATITUDE trials. OS was compared via Kaplan-Meier curves. Analyses were adjusted via propensity score weighting for age, Gleason score, PSA at diagnosis, race, ethnicity, ECOG PS, insurance type and treatment setting. Results: The cohort included 418 Abi pts and 807 Doc pts (Table). Median follow-up was 13.5 mo for Abi and 31.6 mo for Doc. Unadjusted median OS for Abi and Doc were 31.6 mo (95% CI 28.1-NA) and 41.8 mo (95% CI 37.4-46.3) respectively (P=0.09). Twelve mo and 24 mo OS for Abi was 86.3% and 69%; for Doc it was 89.8% and 72.1 %. Median adjusted OS for Abi and Doc were 31.6 mo (95% CI 28.0-undefined) and 38.8 mo (95% CI 33.1-46.3) respectively (P=0.4). Twelve mo and 24 mo adjusted OS for Abi was 86.6% and 69.4%; for Doc it was 87.9% and 69.2%. Based on extracted trial data, in LATITUDE, Abi treated pts had 12 mo and 24 mo OS of 93.5% and 77.0%; in CHAARTED, Doc treated pts had 12 mo and 24 mo OS of 94.3% and 83.6%. Conclusions: Utilizing real-world data, we demonstrate that 12 and 24-months OS are clinically and statistically similar between Abi and Doc in men with mHSPC. Median OS is also similar, although due to limited follow-up, the estimate of median OS for Abi has large variability. In addition, we show that clinical trial pts had superior outcomes to those in a real-world clinic population. Recent meta-analyses of trial data have not found significant differences in OS for Abi vs. Doc; this analysis of real-world data confirms these findings and indicates that they may be generalizable to a broader patient population. Although this observational study is subject to residual confounding and missing data, it provides further evidence to support the use of both Abi and Doc in men with mHSPC. Differentiating costs, side-effects and QOL can thus become more prominent when making decisions about therapy.