e17040 Background: Our aim was to evaluate two distinct clinical settings catering to US patients with metastatic castration-resistant prostate cancer (mCRPC): academic (A) and community (C) practice. We used data from a real-world non-interventional study (REASSURE; NCT02141438) examining the use of 223 Ra. Methods: Patients with mCRPC who received at least one dose of 223 Ra in the US were included. Enrolment occurred between 2014 and 2017; median follow-up was nearly 12 months. Our analysis included patient disease characteristics, treatment history, short- and long-term safety of 223 Ra, patient overall survival (OS), and patient-reported pain (Brief Pain Inventory – Short Form BPI–SF scores). A clinically meaningful pain response was a ≥2-point decrease from a baseline score of ≥2 in the BPI-SF worst pain item during treatment until last dose. Results: Analysis included 498 patients (A: 147; C: 351). Comparing A with C, the median ages were 70 and 76 years, respectively, and the majority of patients (74% and 84%) had bone-only metastases. A higher percentage of patients in A (69%) than in C (49%) had completed at least one life-prolonging therapy (LPT) prior to 223 Ra; these included abiraterone (A: 38%; C: 19%), enzalutamide (A: 32%; C:17%), docetaxel (A: 38%; C: 19%), and sipuleucel-T (A: 18%; C: 25%). Most patients received 5–6 223 Ra injections in both settings (A: 65%; C: 71%). 223 Ra was used concomitantly with LPTs in 48% of patients in A and 57% in C, predominantly with abiraterone (A: 25%; C: 25%) or enzalutamide (A: 25%; C: 36%); fewer patients in A (35%) received concomitant bone health agents than in C (52%). For safety outcomes, refer to the table. During treatment, 47% and 62% of patients with a baseline BPI-SF ≥2 had a clinically meaningful pain response in A and C, respectively. The median OS was 17.2 months (95% CI 14.0–19.4) in A and 18.4 months (14.8–21.0) in C. More patients in A (42%) than in C (26%) received a LPT after 223 Ra, most commonly docetaxel (A: 25%; C: 12%). Conclusions: Patients treated in A tended to be younger and more heavily treated, as evidenced by a higher number of patients receiving LPTs prior to and following 223Ra treatment. Bone health agents were more frequently used in C. Additionally, more patients in C had a clinically meaningful pain response and more drug-related AEs were reported in A. Despite the observed differences, overall survival was comparable for both practice settings. Clinical trial information: NCT02141438 . Table: see text