Background: Cisplatin-based neoadjuvant chemotherapy in muscle-invasive bladder cancer (MIBC) improves survival which correlates with pathologic response (PaR) at radical cystectomy (RC). Immunotherapy with checkpoint inhibitors has improved outcomes in advanced bladder cancer and immunotherapy is synergistic with chemotherapy. Our ongoing trial is aimed at studying the efficacy and safety of nivolumab (N)with gemcitabine-cisplatin (GC) as neoadjuvant therapy for MIBC (NCT03294304). Methods: This is a single-arm, multicenter phase II study for patients with MIBC eligible for neoadjuvant GC and planned for RC. Forty-one patients will be treated with N+ GC every 21 days for 4 treatment cycles over 12 weeks followed by RC. The primary endpoint is PaR. Key inclusion criteria are presence of MIBC (predominantly urothelial carcinoma) with clinical stage T2-T4a and N≤1 disease (solitary lymph node measuring < 2 cm) and M0 and deemed eligible for radical cystectomy, ECOG PS of 0 or 1, Cr Cl ≥ 50 ml/min, adequate organ function, eligible to receive GC and no contraindications to receiving N. Patients will receive C (70mg/m2) IV on D1, G (1000mg/m2) on D1,D8 and N (360 mg) IV on D8 every 21 days for 4 cycles followed by radical cystectomy within 6-8 weeks. Secondary objectives are to determine safety of combination of N+GC in pts with MIBC prior to RC and PFS. The correlative objectives include: 1) correlation of whole-genome sequencing (WGS) of the pre-treatment bladder cancer biopsy with PaR; 2) correlation of molecular subtypes of bladder cancer using Genomedx to evaluate whether addition of N alters the response to neoadjuvant GC; 3) correlation of PD-L1 expression in tumor tissue at baseline with PaR; 4) Nanostring pancan immune panel gene expression will be studied at baseline and at RC. At the time of submission of this abstract, 12/41 pts. have been enrolled and the combination has not resulted in any added toxicities or immune-related AEs so far. There were no delays in RC. PaR and correlative analysis is ongoing in enrolled pts. and further enrollment is ongoing.

Citation Format: Shilpa Gupta, Christopher J. Weight, Neeraj Agarwal, Sumati Gupta, Badrinath Konety, Ewan Gibb, Elai Davicioni, Bharat Thyagarajan, Guru Sonpavde. Neoadjuvant nivolumab, gemcitabine and cisplatin in muscle-invasive bladder cancer: Study update [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A008.