Trajectory timelines and treatment efficacy of 177Lu-PSMA-617 radioligand therapy for metastatic castration-resistant prostate cancer Real-world data from 50 consecutive cases treated in a single Canadian center.

INTRODUCTION

We aimed to evaluate the efficacy and safety of lutetium-177-PSMA-617 in patients with metastatic castration-resistant prostate cancer (mCRPC) following approval in the real-world Canadian clinical context.

METHODS

Data on the first 50 patients with mCRPC who were treated with 177Lu-PSMA-617 at a single center in Quebec, Canada, were retrospectively analyzed. Patients were treated with 7.4 GBq of 177Lu-PSMA-617 administered every six weeks for up to six cycles.

RESULTS

Median (95% confidence interval [CI]) patient age and pre-radioligand therapy prostate-specific antigen (PSA) levels were 72.55 (65.92-76.77) years and 49.19 (15.61-180.65) ng/mL, respectively. Median (95% CI) time between oncologist referral for radioligand therapy and nuclear medicine consultation or first dose of 177Lu-PSMA-617 were 12 (7.0-32.0) and 42 (28.0-54.0) days, respectively. Overall, 26.0% of patients completed six radioligand therapy cycles. Declines in PSA levels of 25%, 50%, and 90% were reached in 57%, 51%, and 17% of patients, after a median of two, two, and three cycles, respectively. At last followup, after a mean followup time of 8.5 months, 61% (25/41) of patients not on ongoing therapy were alive, with an estimated median overall survival of 13.0 months (95% CI 8.0-not reached).

CONCLUSIONS

Real-world data show that use of 177Lu-PSMA-617 in patients with mCRPC is feasible in a universal healthcare system, with comparable oncologic activity to that observed in the phase 3 VISION trial. The study is limited by the short followup and its retrospective nature.