Survival outcomes of patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) receiving lutetium-177-PSMA-617 (Lu) based on line of therapy.

Abstract

82 Background: Lu is a prostate-specific membrane antigen (PSMA)-targeted radiopharmaceutical that delivers beta radiation to PSMA-positive cells. It is approved for pts with mCRPC who had prior progression on an androgen receptor pathway inhibitor (ARPI) and taxane-based chemotherapy. However, there are limited real-world data on the efficacy of Lu based on the line of therapy. Herein, we aimed to assess the survival outcomes of pts with mCRPC receiving Lu in a real-world setting. Methods: This retrospective study utilized the nationwide Flatiron Health electronic health record (EHR) derived de-identified database. Eligibility: pts diagnosed with mCRPC who received Lu for the first time. Survival was calculated from the date pts received their first treatment with Lu. Time to next treatment (TTNT) and overall survival (OS) were summarized using Kaplan Meier survival estimates and its 95% confidence intervals (CI). Results: Of the overall cohort of 24,105 pts with metastatic prostate cancer in the dataset, 303 diagnosed between 1/1/2013 and 7/11/2023 received treatment with Lu. The median age of these pts was 75 years (IQR 69 – 80). The majority were White non-Hispanic (69%), treated in a community practice (82%), covered by a commercial health plan (86%), and received Lu in the third line or later (91.4%). For pts treated with Lu, the median TTNT was 8.5 months (95% CI, 7.3 – 9.8), and the median OS was 12 months (95% CI, 11 – 15). Median TTNT and OS by line of therapy are summarized (Table). Conclusions: Lu retains clinical activity in pts with mCRPC regardless of line of therapy. These data may aid with patient counseling, prognostication, and selection of therapy in the clinic. Median TTNT and OS by line of therapy in pts with mCRPC receiving Lu. Line of therapy Number of pts, n (%) Median TTNT (mo) (95% CI) Median OS (mo) (95% CI) 2 26 (8.6) 8.5 (5.6, -) 12 (8.5, -) 3 77 (25.4) 8.0 (6.4, 11) 17 (8.9, -) 4 82 (27) 8.2 (6, 10) 10 (7.2, 22) 5 64 (21) 9.8 (6, 13) 13 (11, -) 6 28 (9.2) 9 (5.7, -) 13 (12, -) 7 17 (5.6) 10 (7.3, -) 10 (7.3, -) 8 6 (2) 7 (3.7, -) (3.7, -) 9 2 (0.7) 7.3 (3, -) 10 (8.6, -) 14 1 (0.3) 8.6 (-, -) 14 (-, -)