Real-world treatment patterns in the US and trends pre-post CARD trial among patients with metastatic castration-resistant prostate cancer.

e17024 Background: Numerous treatments with different mechanisms of action are approved for metastatic castration-resistant prostate cancer (mCRPC). The sequencing for management of these patients has been evolving post availability of trials such as the CARD trial, looking at clinical outcomes post androgen receptor pathway inhibitor (ARPI) and docetaxel. This study examined real-world treatment patterns and sequencing among United States patients with mCRPC. Methods: This retrospective cohort study used Flatiron Health electronic health record data from Jan 1, 2013 to June 30, 2020 (study period). Included patients were male aged ≥18 years, had a confirmed diagnosis of mCRPC within the study period, and received ≥1 systemic therapy post-mCRPC diagnosis. Index date was the date of first-line (1L) therapy initiation post-mCRPC diagnosis. Patient characteristics and treatment patterns were evaluated descriptively. Across analyses, treatments were grouped as follows: ARPI (abiraterone, enzalutamide), taxane (docetaxel, cabazitaxel), sipuleucel-T, radium-223, targeted therapy (TT; olaparib, rucaparib), mitoxantrone, combo therapy (any combination regimen containing ≥1 of the preceding therapies), and other (any other therapy or combination of therapies). Results: 2,588 patients were included in the study; mean±SD age was 72±8 years and 66% were White. The most common 1L therapy was ARPI (63%), followed by taxane (11%), combo therapy (11%), radium-223 (6%), sipuleucel-T (6%), and other therapy (2%). No patient received TT or mitoxantrone alone in 1L. Median time to next treatment post-1L was longest for combo therapy (8.1 months) and ARPI (7.6 months) and shortest for sipuleucel-T (3.4 months). The most common sequence of treatment for mCRPC patients was 1L ARPI to another ARPI at second-line (2L) (29%); taxane and combo therapy (both 14%) were the next most common (Table). Treatment patterns were similar pre- and post- read-out of the CARD trial. Conclusions: The majority of mCRPC patients who receive 1L ARPI will receive another at 2L rather than switching to an alternative type of treatment.[Table: see text]