A phase II trial of risk-adapted treatment for muscle invasive bladder cancer after neoadjuvant accelerated MVAC.

TPS537 Background: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by cystectomy (Cx) or chemoradiation (CRT) is the standard of care for urothelial carcinoma (UC) pts with muscle invasive bladder cancer (MIBC). Both Cx and CRT carry potential short and long-term toxicity and quality of life implications. Recent work has shown that mutations in DNA damage repair/response genes are predictive of pathologic downstaging after NAC at the time of Cx, with those pts achieving pT0 disease demonstrating excellent long-term survival (Van Allen et al. Cancer Discov. 2014; Plimack et al. Eur Urol. 2015; Liu et al. JAMA Oncol. 2016; Teo et al. CCR. 2017). Sparing pts Cx or CRT after NAC without compromising oncologic outcomes would improve quality of life and decrease morbidity. Methods: A phase II, parallel arm, multi-institutional clinical trial (NCT02710734) is being conducted to evaluate a risk-adapted approach to treatment of MIBC. Pts with cT2-T3N0M0 UC of the bladder, ECOG PS 0-1 and CrCl≥50 mL/min, undergo NAC with accelerated methotrexate, vinblastine, doxorubicin, and cisplatin. Simultaneously, the pre-NAC TURBT specimen is submitted for deep sequencing to identify variants in a panel of cancer-relevant genes (Caris Life Sciences, Phoenix, AZ). Those with an alteration in ATM, RB1, FANCC or ERCC2 and no clinical evidence of disease by restaging TUR and imaging post-NAC will begin a pre-defined active surveillance regimen that includes urinary cytological, cystoscopic, and radiographic evaluations. The remaining pts will undergo bladder-directed therapy at the discretion of the pt and clinician applying either intravesical therapy ( < cT2 post-NAC), CRT or Cx (≤cT2 post-NAC) or Cx (≥cT3 post-NAC). The primary objective is metastasis-free survival (MFS) at 2 years for all enrolled and evaluable pts. The trial has a non-inferiority design with a 14% margin between risk-adapted treatment (MFS = 78%) and standard-of-care (MFS = 64%) with a sample size of 70 pts, 82% power and a type I error of 0.045. Key secondary and translational objectives: assess the rate of UC recurrence in active surveillance pts; validate biomarkers of response to NAC; evaluate urinary biomarkers consistent with persistent UC. Clinical trial information: NCT02710734.