LuRa: Efficacy and Safety of Radium-223 Following [¹⁷⁷Lu]Lu-PSMA-617 in Patients With Metastatic Castration-Resistant...

Area of Science:

• Oncology
• Nuclear Medicine
• Urologic Oncology

Background:

• The introduction of Lutetium-177 PSMA-617 (177Lu-PSMA-617) has altered treatment paradigms for metastatic castration-resistant prostate cancer (mCRPC).
• Limited data exists on the efficacy and safety of subsequent therapies following 177Lu-PSMA-617 administration.

Purpose of the Study:

• To evaluate the outcomes and safety of Radium-223 (Ra-223) treatment in patients with mCRPC who have previously received 177Lu-PSMA-617.
• To assess endpoints including efficacy, hematologic toxicities, and skeletal-related events.

Main Methods:

• Retrospective, multi-institutional analysis of mCRPC patients treated with Ra-223 post-177Lu-PSMA-617.
• Evaluation of efficacy (PSA response, alkaline phosphatase reduction, survival) and tolerability (hematologic toxicity, skeletal-related events).

Main Results:

• Among 21 patients, 19% completed all Ra-223 cycles; disease progression was the primary reason for discontinuation (62%).
• Grade ≥3 anemia (33%) and thrombocytopenia (19%) were observed, with 38% requiring transfusions.
• Median PSA progression-free survival was 2.5 months, and median overall survival was 10.6 months; 76% survived 6 months post-Ra-223 initiation.

Conclusions:

• Radium-223 (Ra-223) shows feasibility and efficacy in heavily pre-treated mCRPC patients following 177Lu-PSMA-617.
• Observed hematologic toxicities and skeletal events necessitate careful patient selection and monitoring during Ra-223 therapy.