Background: mCSPC patients treated with docetaxel + androgen deprivation therapy (D+ADT) demonstrate increased overall survival (OS)^1,2. However, limited real-world outcome data is available for such patients. This study assesses the real-world use and outcomes with D+ADT in mCSPC in the US. Methods: Adult (≥18 years old) men with mCSPC (defined as men with metastasis at index diagnosis of prostate cancer [de novo] or those who progressed to mCSPC after prior diagnosis of localized disease) were retrospectively identified from the Optum (2007–2018) and SEER Medicare (2007–2016) databases. Men diagnosed with mCSPC in or after 2014 with exposure to docetaxel and no brain metastasis were included for analysis. Patients were characterized based on age; baseline prostate specific antigen (PSA) level; administration of ADT; prior radiotherapy (RT); prior radical prostatectomy (RP); presence of visceral disease, bone or bone + visceral metastases; and treatment duration of docetaxel. OS and time to metastatic castration-resistant prostate cancer (mCRPC) were measured. Results: Among 4959 men identified with mCSPC during or after 2014, 192 (3.8%) received D+ADT ± Bicalutamide as first line systemic therapy. Baseline characteristics are presented in the Table below. Mean ± SD duration of docetaxel exposure was 115 ± 84.2 days (median 118 days). Median OS among these men was 30.5 (28.1, 36.7) months and median time to mCRPC was 18.3 (14.5, 24.6) months. Only 9% of men received docetaxel for ≥6 cycles (180 days); median OS in these men was NR (19.1- NR) with 74% surviving at 2 years compared to 65% surviving at 2 years in those with docetaxel duration <6 cycles. Conclusions: Use of docetaxel in the real-world mCSPC patient population in the US is limited. Majority of men received less than the recommended dose of 6 cycles. OS with D+ADT in real-world patients with mCSPC appears to be lower than the OS reported in published trials. References:1) Sweeney CJ, et al. N Engl J Med. 2015;373:737–46. 2) James ND, et al. Lancet. 2016;387:1163–77. Funding: Janssen Research & Development, LLC.