Efficacy and Safety of Bladder Preservation Therapy in Combination with Atezolizumab and Radiation Therapy (BPT-ART) for Invasive Bladder Cancer: Interim Analysis from a Multicenter, Open-label, Prospective Phase 2 Trial

• DOI: 10.1016/j.ijrobp.2023.05.013
• Publication Date: 2023-05-16T03:53:47Z
• Authors: Tomokazu Kimura; Hitoshi Ishikawa; Yoshiyuki Nagumo; Yuta Sekino; Yukio Kageyama; Hiroki Ushijima; Taketo Kawai; Hideomi Yamashita; Haruhito Azuma; Keiji Nihei; Masae Takemura; Koichi Hashimoto; Kazushi Maruo; Toyonori Tsuzuki; Hiroyuki Nishiyama
• Keywords: Dysuria; Atezolizumab; Interim analysis; Clinical endpoint

PURPOSETo evaluate the safety and pathological complete response (pCR) rate of radiotherapy with atezolizumab as bladder-preserving therapy for invasive bladder cancer.PATIENTS AND METHODSA multicenter, phase II study was conducted clinically T2-3 or very high-risk T1 cancer patients who were poor candidates refused radical cystectomy. Here, we report our interim analysis pCR a key secondary endpoint ahead progression-free survival primary endpoint. Radiotherapy (41.4 Gy to small pelvic field 16.2 whole bladder) given plus 1200 mg intravenous every 3 weeks. After 24 treatment weeks, assessed after transurethral resection tumor programmed cell death ligand-1(PD-L1) expression using tumor-infiltrating immune scores.RESULTSForty-five enrolled from January 2019 May 2021 analyzed. The most common clinical T stage T2 (73.3%), followed by (15.6%) T3 (11.1%). Most tumors solitary (77.8%), (<3 cm) (57.8%), without concurrent carcinoma in situ (88.9%). Thirty-eight (84.4%) achieved pCR. High rates older (90.9%) high PD-L1-expressing (95.8% vs. 71.4%). Adverse events (AEs) occurred 93.3% patients, diarrhea being (55.6%), frequent urination (42.2%) dysuria (20.0%). frequency grade AEs 13.3% while no 4 observed.CONCLUSIONCombination provides acceptable toxicity, indicating it could be promising option preservation therapy.