Retreatment of Metastatic Castration-Resistant Prostate Cancer Patients with ²²³Ra Therapy in Daily Practice

Area of Science:

• Oncology
• Radiopharmaceuticals
• Prostate Cancer Therapeutics

Background:

• Metastatic castration-resistant prostate cancer (mCRPC) with bone metastases presents significant treatment challenges.
• Radium-223 dichloride (²²³Ra) is an approved therapy, with potential for retreatment after an initial course.

Purpose of the Study:

• To evaluate the safety and efficacy of ²²³Ra retreatment in a real-world mCRPC population.
• To identify predictors of treatment completion and survival during ²²³Ra retreatment.

Main Methods:

• Multicenter, retrospective cohort study of mCRPC patients receiving ²²³Ra retreatment.
• Primary endpoint: safety (hematologic and nonhematologic adverse events).
• Secondary endpoints: injections administered, overall survival, biochemical response rates.

Main Results:

• Sixty-one patients evaluated; median age 75 years.
• ²²³Ra retreatment was well-tolerated, with no grade 4 or 5 adverse events.
• Median overall survival was 16.9 months; 56% showed ≥30% alkaline phosphatase response.

Conclusions:

• ²²³Ra retreatment is safe and potentially beneficial for selected mCRPC patients.
• High hemoglobin, prior PSA response, and no prior chemotherapy predicted retreatment completion.
• Patients with good performance status and prior PSA response may benefit most from retreatment.