(UroToday.com) The clinical benefit of radium-223 has been demonstrated in patients with metastatic castration resistant prostate cancer (mCRPC) in the ALSYMPCA randomized placebo controlled trial.1 Over the last nearly decade since publication of this landmark trial, combination therapy in patients with mCRPC is of great interest for improving efficacy but must be done in a safe manner for these patients. Agarwal et al. previously reported that treatment with enzalutamide plus Radium-223 was associated with a decline in serum bone metabolism markers, which correlated with improved outcomes compared to enzalutamide alone.2 At the GU ASCO 2021 annual meeting, medical student Adam Kessel and colleagues presented results of the final efficacy and safety results for this trial.