Circulating tumor DNA (ctDNA) to guide response-adapted bladder preservation in muscle invasive bladder cancer (MIBC): Integrated analysis of the RETAIN trials.

作者：Pooja Ghatalia, Eric A. Ross, Matthew R. Zibelman, Fern Anari, Phillip Phillip Abbosh, Cameron Herberts, Patrick Mille, Tracy L. Rose, Suzanne Cole, James Ryan Mark, Rosalia Viterbo, Eric M. Horwitz, M.A. Hallman, Andres Correa, M C Smaldone, R. Uzzo, David Chen, A. Kutikov, Elizabeth R. Plimack, Daniel M. Geynisman · 发表于：Journal of Clinical Oncology · 年份：2026 · DOI：10.1200/jco.2026.44.7_suppl.lba632 · 被引用次数：7 · 研究领域：Bladder and Urothelial Cancer Treatments、Cancer Genomics and Diagnostics、Prostate Cancer Treatment and Research

LBA632 Background: The phase II RETAIN 1 and 2 trials evaluated a response-adapted approach to identify pts with MIBC who may safely undergo cystectomy-sparing active surveillance (AS) after neoadjuvant therapy (tx). RETAIN-1 evaluated AMVAC and RETAIN-2 combined nivolumab with AMVAC. Although ctDNA is prognostic in pts treated with cystectomy, its role in selecting or monitoring pts on AS is unknown. We report updated RETAIN-2 outcomes and an integrated ctDNA analysis from RETAIN-1/2 to evaluate the role of ctDNA in risk stratification for bladder preservation. Methods: RETAIN-2 enrolled pts with cT2-T3N0M0 MIBC treated with AMVAC plus nivolumab. TURBT samples were sequenced for ATM , ERCC2 or RB1 mutations. Pts with >1 mutation and clinical complete response (restaging TUR, urine cytology and CT), entered AS; others received bladder-directed tx. The primary endpoint was 2-yr metastasis-free survival (MFS) in the ITT population. Plasma from both trials was analyzed with Signatera at baseline and post-tx; RETAIN-2 included 3- and 6- mo draws. Results: Among 71 evaluable RETAIN-2 pts (median age 68; 77% male; 42% cT3), 57 (80.3%) remained metastasis-free at 29.2-mo follow-up. The estimated 2-yr MFS was 79.8% (95% CI 70–90%) in the ITT population and 80% (95% CI 64–100%) in AS pts. Among 22 AS pts, 8 (36%) had bladder recurrence, 4 (18%) developed metastases, 4 needed salvage cystectomy, 3 salvage chemoradiation; 16 (73%) remained metastasis-free with an intact bladder. Acro...