Dual Immune Checkpoint Therapy Combined with Radiotherapy Treats Castration-Resistant Prostate Cancer

The triple combination therapy of anti-CTLA-4 + anti-PD-1 + radiotherapy 20 Gy in 2 treatments proved statistically superior in survival and tumor growth delay compared to dual and monotherapies. While clinical studies have tested anti-CTLA-4 + anti-PD-1 for metastatic CRPC, this preclinical model indicates the addition of RT significantly improves in survival and tumor growth delay among FBV mice. This work elucidates the simultaneous use of two immune checkpoint inhibitors in combination with RT has the greatest anti-tumor activity and should be considered in design of clinical trials for metastatic CRPC.