Final PEACE-3 Trial Data: Radium-223 + Enzalutamide Extends Survival by 5.6 Months in Bone mCRPC.

Radium-223 plus enzalutamide significantly boosts survival for men with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases, according to final results from the Phase 3 PEACE-3 trial  presented at ASCO GU 2026.
In this study of 446 patients with at least two bone metastases who were asymptomatic or only mildly symptomatic, adding six infusions of radium-223 (a bone-targeting alpha-emitter) to daily enzalutamide (160 mg) extended median overall survival to 38.2 months, compared to 32.6 months with enzalutamide alone, a hazard ratio of 0.76 with P=0.0096. The combination also improved radiographic progression-free survival (rPFS) to a median of 19.2 months versus 16.4 months (HR 0.71), with benefits holding up after a median 58-month follow-up that locked data in January 2026. Early survival curves crossed around 18 months but separated in long-term favor of the combo, showing consistent gains across subgroups regardless of prior treatments.
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Safety remained manageable, with mostly moderate added side effects like anemia or gastrointestinal issues but no new safety signals; experts recommend pairing with bone-protective agents to mitigate risks. Researcher describe it as ideal for first-line use even after prior androgen receptor pathway inhibitors (ARPIs), a potential new standard for bone-dominant disease. Radium-223 homes in on bone metastases via calcium mimicry, delivering targeted radiation that spares marrow more than alternatives, while enzalutamide blocks androgen signaling, together addressing both local tumor burden and systemic progression.

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