338MO - Efficacy and safety of tislelizumab (T) combined with gemcitabine and cisplatin (GC) for patients with localized muscle-invasive bladder cancer (MIBC) after radical local surgery: A prospective, phase II study

Background

Transurethral resection of bladder tumor (TURBT) combined with concurrent chemoradiotherapy is the standard treatment for bladder preservation in MIBC. TURBT alone and partial cystectomy are only suitable for selected patients with solitary tumors, T2, and tumors in the bladder diverticulum. One of the major concerns is the possibility of residual tumor and the increasing risk of metastasis after surgery. Systemic treatment after radical TURBT or partial cystectomy may prevent recurrence and metastasis. This study aims to explore the efficacy and safety of T combined with GC after radical TURBT or partial cystectomy as bladder preservation therapy in patients with PD-L1 positive MIBC.

Methods

This study is a prospective phase II clinical trial. Eligible patients must have clinical stage T2-T3N0M0, histologically confirmed urothelial carcinoma, PD-L1 positive, no previous systemic treatment, and no residual tumor after radical TURBT or partial cystectomy. Patients received T combined with GC (G 1000mg/m2, d1, d8; C 70mg/m2, d1, IV, q3w, for a total of 6 cycles. T 200mg, d8, IV, q3w, for a total of 8 cycles). The primary endpoint was 1-year bladder intact disease-free survival rate. Secondary endpoints included 2-year bladder intact disease-free survival rate, metastasis-free survival, time to salvage cystectomy, overall survival, and safety.

Results

From August 2022 to June 2024, a total of 10 patients were enrolled in the study. Median age was 70 years (65-75). 9 patients were T2 and 1 patient was T3. 8 patients were evaluable for efficacy. 5 patients underwent TURBT and 3 patients underwent partial cystectomy. The median follow-up time was 10.5 months. None of the 8 patients had tumor recurrence or metastasis. 1-year bladder intact disease-free survival rate was 100% . Grade 3 or higher adverse events occurred in 37.5% of patients. No new safety signals were observed.

Conclusions

The study demonstrated that combination of T and GC after complete resection of tumor seemed promising as bladder preservation strategy in selected patients. Further recruitment is ongoing.

Clinical trial identification

NCT05401279.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.