Radium-223 is used to treat prostate cancer bone metastases, though its mechanism of action isn’t specific to prostate cancer. RADICAL was a phase II trial that enrolled 98 patients with metastatic RCC and at least one bone metastasis. They were randomized to receive cabozantinib with or without radium-223. The addition of radium-223 did not significantly increase median symptomatic skeletal event free survival (16.7 v 17.6 months). Radium did not significantly increase adverse events, but it also didn’t help with response rate or overall survival. | McKay, J Clin Oncol 2026
