Efficacy and safety of the combination of cisplatin plus nab-paclitaxel and nivolumab with radiotherapy after maximal tumor resection in non-metastatic muscle invasive bladder cancer (CNN-BC trial).

Abstract

TPS723 Background: The therapeutic gold standard for muscle invasive bladder cancer (MIBC) is radical cystectomy (RC) preceded by neoadjuvant chemotherapy when appropriate. However, RC is a major surgery procedure with 13% rate of severe complication and a perioperative mortality rate of about 1.5 - 5 %. Trimodal therapy (TMT) is a “bladder sparing” option alternative to RC. TMT consists of complete transurethral bladder tumor resection (TURBT) followed by a combination of systemic chemotherapy and locoregional radiotherapy (RT), with the option of “salvage” cystectomy in case of local treatment failure. Immunotherapy with anti-PD1/PD-L1 monoclonal antibody significantly improves survival of metastatic BC patients, and it seems to potentiate the activity of RT without increased toxicity. Therefore, we investigate the role of a multimodal TMT strategy to increase the disease-free survival (DFS) and avoid or delay RC in non-metastatic MIBC pts. Methods: CNN-BC trial (NCT05203913) is a phase 2, open-label, mono-institutional study evaluating the activity and safety of TMT with cisplatin, nab-paclitaxel and nivolumab as systemic therapy in non-metastatic MIBC pts. Eligible pts should have undergone complete TURBT with diagnosis of T2-T3 N0M0 urothelial carcinoma, and no evidence of lymph nodes or metastatic disease at FDG-PET within 6 weeks from the start of treatments. TMT consists of nivolumab (480 mg IV every 4 weeks for a total of 13 doses), weekly nab-paclitaxel (60mg/m2) plus cisplatin (20mg/m2) administered concurrently with RT (60Gy in 25 fractions over 5 weeks on original bladder tumor, plus a concomitant boost of 50Gy in 25 fractions on whole bladder and pelvic nodes). The primary endpoint is the 1-year DFS rate, defined as the rate of survival free of recurrence in pelvic nodes or bladder, or appearance of distant metastases. Secondary endpoints include: the rate of pts who require salvage cystectomy, the rate of locoregional complete response (CR) and of locoregional DFS, median DFS, safety, and quality of life. Exploratory biomarkers analysis will be performed. The trial is actively recruiting. Clinical trial information: NCT05203913 .