Tumor mutational burden as predictor of first-line ICI versus carboplatin benefit for metastatic urothelial carcinoma in cisplatin-unfit patients

Real-world patients with metastatic urothelial carcinoma (mUC) are often more frail than clinical trial patients, underscoring an unmet need to identify patients who might be spared first-line chemotherapy. A study at 280 US centers found that among cisplatin-ineligible mUC patients, tumor mutational burden (TMB) 10 mut/Mb or higher was associated with more favorable PFS, TTNT, and OS with first-line immune checkpoint inhibitors (ICIs) compared with lower TMB. TMB ≥ 10 also identified patients with more favorable PFS, TTNT, and OS with first-line ICIs compared with carboplatin.