Real world outcomes of ¹⁷⁷ Lu-PSMA-617 PSMA in a racially diverse cohort of patients with metastatic castration resistant prostate cancer (mCRPC).

97 Background: 177 Lu-PSMA-617 is approved for treatment of mCRPC based on the VISION trial cohort with limited racial diversity. We analyzed real-world outcomes of 177 Lu-PSMA-617 in a diverse cohort. We aim to determine patient characteristics predictive of a clinical response to 177 Lu-PSMA-617. Methods: A retrospective analysis was conducted on patients with mCRPC treated with 177 Lu-PSMA-617 at Emory Winship Cancer Institute between 2022-2024. Primary endpoints were PFS, OS, and PSA reduction ≥ 50% (PSA50). Univariate association by survival analysis and logistic regression was carried out. Results: We analyzed 84 patients with PSMA PET+ mCRPC treated with 177 Lu-PSMA-617; 47.6% identified as Caucasian and 42.9% identified as Black. The median cohort age was 71.5 (IQR: 64-77.5). 35.6% had grade group 5 disease. Median number of prior lines of therapy was 5 (range: 4-7). 98.8% of patients had prior treatment with novel hormonal agents; 84.5% received prior taxane treatment. 84.5% were characterized as high-volume diseases using the CHAARTED trial criterion. Median baseline PSA was 105.5 (IQR: 20.4-454.8), and ALP was 103.5 (IQR: 72-177.5). The cohort completed a median number of 4 cycles of 177 Lu-PSMA-617; 35.7% completed six cycles. The overall cohort had a 12-month survival of 84.4%. 12-month survival rate was 88.3% in the white cohort compared to 81.4% in the non-white cohort. mPFS for the overall cohort was 6 months with a 12-month PFS rate of 41.9%. 12-month mPFS for the non-white cohort was 42.7% compared to 41.5% in the white cohort. 50.0% of the overall cohort had a PSA50 response. 56.1% of the non-white cohort had a PSA50 compared to 43.9% of the white cohort (p=0.377). Net BMI decline during treatment was associated with a 56% increased risk of mortality (OS HR 1.56, CI 1.18-2.06, p<0.002). Conclusions: With similar PFS, OS, and PSA50 in this racially diverse cohort of patients with mCRPC, our results demonstrate 177 Lu-PSMA-617 effectiveness in a real-world patient population. Prospective studies are needed for further validation.