Tislelizumab, a PD-1 inhibitor, combined with nab-paclitaxel may offer another treatment option for high-risk nonmuscle-invasive bladder cancer (NMIBC), according to preliminary findings from the phase 2 TRUCE-02 trial presented at the 2022 ASCO Annual Meeting.
From July 2020 to January 2022, the trial (ClinicalTrials.gov Identifier: NCT04730232) enrolled 54 patients with high-risk NMIBC tumors that were not completely resectable.
Patients received tislelizumab 200 mg on day 1 plus paclitaxel 200 mg on day 2 every 3 weeks for 3 or 4 cycles over 12 weeks, followed by transurethral resection biopsy, urine cytology, and imaging. The primary endpoint was complete response (absence of NMIBC or progressive disease). Patients had a mean follow-up of 9 months.
Of the 54 patients enrolled, 42 completed 3 or 4 treatment cycles. Investigators observed a complete response in 23 (55%) patients, partial response in 2 (5%) patients, and no response in 17 (40%) patients, HaiTao Wang, MD, PhD, of Tianjin Medical University in China, reported.
A total of 25 patients (60%) had an objective response, and 28 patients (66.7%) remain cystectomy-free. The 12-month bladder-intact disease-free survival rate was 62.7%. The rate of grade 3 to 4 adverse events was below 2%, according to Dr Wang.
Urine cytology and urine FISH had a diagnostic efficacy of 68.42% and 45.71%, respectively, prior to pathologic assessment.
With respect to PD-L1 expression, 53% of responders (both complete and partial) and 50% of nonresponders were positive.
“PD-L1 expression has no obvious correlation with the efficiency of this treatment plan,” Dr Wang said.
Wang HT, Hu H, Niu Y, et al. TRUCE-02: An open label, single-arm, phase II study of tislelizumab combined with nab-paclitaxel for high-risk non-muscle-invasive urothelial bladder carcinoma. Presented at ASCO 2022; June 3-7, 2022. Abstract 4507.