Radical cystectomy (RC) is recommended for muscle-invasive
bladder cancer (MIBC) or highest-risk
non-muscle-invasive bladder cancer (
NMIBC). Trimodal
therapy (TMT) is the most favorable strategy among bladder preservation
therapies (BPT) for patients who are ineligible for or refuse RC. However, referrals for TMT, especially following
chemotherapy, are limited by the patient's condition. Therefore, new BPT approaches are needed.
Atezolizumab inhibits
programmed death-ligand 1, is well-tolerated in patient populations heavily dominated by
renal insufficiency, and is expected to have synergistic anti-
tumor effects in combination with
radiation therapy (RT). Therefore, we have conducted this open-label phase II multicenter study to evaluate the efficacy and safety of RT in combination with
atezolizumab for T2-3 MIBC and highest-risk T1
NMIBC patients. This study was initiated in January 2019, and we aimed to enroll a total of 45 patients. The study is registered in the Japan Registry of Clinical Trials (Identifier: RCT2031180060).