Radionuclide Combination Strategies in Prostate Cancer: Insights from the AlphaBet Trial

Area of Science:

• Oncology
• Nuclear Medicine
• Radiotherapy

Background:

• Lutetium-177 prostate-specific membrane antigen ([¹⁷⁷Lu]Lu-PSMA) therapy has improved outcomes for advanced prostate cancer.
• Treatment resistance and disease progression remain significant challenges.
• Radionuclide combination strategies, including alpha- and beta-emitter pairings, are being explored to enhance efficacy and overcome limitations of [¹⁷⁷Lu]Lu-PSMA monotherapy.

Purpose of the Study:

• To evaluate the feasibility and safety of combining radium-223 ([²²³Ra]), an alpha-emitter, with [¹⁷⁷Lu]Lu-PSMA therapy.
• To explore novel radionuclide combinations and treatment sequencing for metastatic castration-resistant prostate cancer (mCRPC).
• To investigate biomarker-driven approaches for patient selection in advanced prostate cancer treatment.

Main Methods:

• The AlphaBet trial investigated the combination of radium-223 and [¹⁷⁷Lu]Lu-PSMA in patients with mCRPC.
• Assessment of feasibility, safety, and complementary targeting properties of the combined approach.
• Ongoing studies are evaluating other combinations, optimal sequencing, and patient selection strategies.

Main Results:

• The AlphaBet trial demonstrated the feasibility and safety of combining radium-223 with [¹⁷⁷Lu]Lu-PSMA.
• The combination leverages complementary spatial targeting and radiophysical properties of the radionuclides.
• Further research is ongoing to assess long-term benefits and safety.

Conclusions:

• Radionuclide combination strategies, such as pairing alpha- and beta-emitters, offer a potential avenue to overcome resistance in advanced prostate cancer.
• [¹⁷⁷Lu]Lu-PSMA combined with radium-223 is a feasible and safe approach.
• Continued research is essential to confirm the long-term efficacy and safety of these novel treatment strategies for improved patient outcomes.