Comparative effectiveness of ICIs versus chemotherapy by tumor mutational burden in metastatic castration-resistant prostate cancer

There is a need for biomarkers that might identify patients with metastatic castration-resistant prostate cancer (mCRPC) likely to receive greater clinical benefit from immune checkpoint inhibitors (ICIs) than from other therapies. Analysis of patients with previously treated mCRPC receiving single-agent ICI or single-agent taxane chemotherapy found that in patients with tumor mutational burden <10 mt/Mb taxane chemotherapy resulted in longer time to next treatment and similar overall survival, whereas in patients with tumor mutational burden ≥ 10 mt/MB ICI resulted in longer time to next treatment and superior overall survival. The authors conclude that ICIs may be a viable alternative to taxane chemotherapy for mCRPC with high tumor mutational burden.