An analysis of reconstructed individual patient data from the phase 3 EORTC 1333/PEACE-3 trial found that combining Enzalutamide with Radium-223 produced a delayed but meaningful long-term survival benefit in patients with metastatic castration-resistant prostate cancer (mCRPC).
Researchers reported that the combination showed little survival advantage during the first 18 months of active treatment, but benefits became more apparent over time as the effects of radium-223 accumulated. By 72 months, restricted mean survival time analysis demonstrated a significant 6.25-month survival improvement compared with enzalutamide alone, with survival times of 43.23 months versus 36.98 months.
Among patients surviving into the 60-to-72-month period, the combination reduced the risk of death by 80%. Early treatment risks were linked to fractures and cardiovascular toxicities before bone-protecting agents became mandatory. Investigators said patients likely need sufficient life expectancy to gain the full long-term benefit of the regimen.