Survival outcomes based on line of therapy and treatment trends with cabazitaxel in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC).

162 Background: Pts with mCRPC after progression on docetaxel and androgen receptor pathway inhibitors (ARPIs), have limited treatment options. Even with the changing landscape, cabazitaxel remains an effective approved therapy in this setting for these pts. However, real-world data on the efficacy and trends of cabazitaxel usage remain limited. Herein, we aimed to assess the survival outcomes and treatment patterns in pts with mCRPC receiving single-agent cabazitaxel in a real-world setting. Methods: This retrospective study utilized the nationwide Flatiron Health electronic health record (EHR) derived de-identified database. Eligibility: Diagnosis of mCRPC and receipt of single-agent cabazitaxel for the first time. Survival was calculated from the date pts received their first treatment with cabazitaxel. Time to next treatment (TTNT) and overall survival (OS) were summarized using Kaplan Meier survival estimates and its 95% confidence intervals (CI). Results: Among 24,105 pts with metastatic prostate cancer in the dataset, 1,315 pts diagnosed between 1/1/2013 and 1/26/2024 received single-agent cabazitaxel. Median age of pts was 73 years (IQR 67 – 78). The majority were non-Hispanic White (62%), treated in community practice (84%), had commercial insurance (81%), and received treatment in the third line or later (86%). The number of pts receiving cabazitaxel per year steadily increased from 2 (0.2%) in 2012 to a peak of 181 pts (14%) in 2021. Following the approval of lutetium-177-PSMA-617 (Lu) in 2022, cabazitaxel usage declined to 126 pts (9.6%) in 2023, indicating a shift in treatment patterns. The median TTNT was 4.7 months (95% CI, 4.4–5.0), and the median OS was 8.6 months (95% CI, 8.0–9.3) for pts treated with cabazitaxel. Median TTNT and OS by line of therapy are summarized (Table) . Conclusions: Despite proven OS benefit, the overall utilization of cabazitaxel is low in real-world pts in the US. The number of pts with mCRPC receiving cabazitaxel steadily increased until 2021 and declined following the approval of Lu in 2022, highlighting the evolving treatment landscape. Cabazitaxel continues to be an effective therapy regardless of line of therapy. Median TTNT and OS by line of therapy in pts with mCRPC receiving cabazitaxel. Line of therapy Number of pts, n (%) Median TTNT (mo) (95% CI) Median OS (mo) (95% CI) 2 183 (13.9) 5.7 (4.8, 6.3) 11 (9.5, 14) 3 378 (28.7) 4.3 (3.8, 4.7) 7.5 (6.6, 8.4) 4 430 (32.7) 4.5 (4.1, 4.8) 8.5 (7.5, 9.4) 5 219 (16.7) 5.1 (4.4, 5.9) 9.2 (8.0, 12) 6 71 (5.4) 5.1 (4.1, 5.9) 7.7 (5.9, 11) 7 22 (1.7) 6.8 (2.8, 12) 11 (8.2, 18) 8 6 (0.5) 4.9 (1.8, -) 6.3 (1.8, -) 9 6 (0.5) 4.2 (2.8, -) 14 (9.7, -)