A Phase 2 Trial of Intravesical Gemcitabine and Docetaxel in the Treatment of Bacillus Calmette-Guérin‒Naïve Nonmuscle-Invasive Urothelial Carcinoma of the Bladder

Abstract

Purpose: Combination intravesical gemcitabine and docetaxel (GemDoce) has demonstrated efficacy as second-line therapy for patients with bacillus Calmette-Guérin (BCG)‒unresponsive nonmuscle-invasive urothelial carcinoma of the bladder (NMIBC). In the context of widespread BCG shortages, we performed a phase 2 prospective trial to assess GemDoce for BCG-naïve NMIBC.

Materials and methods: This study is a prospective, single-arm, open-label phase 2 trial for patients with BCG-naïve high-risk NMIBC. Intravesical GemDoce was given weekly for 6 weeks as induction followed by monthly maintenance therapy for 2 years among responders. The primary end point was 3-month complete response, and key secondary end points included adverse events (AEs) and 12-month recurrence-free survival.

Results: Twenty-five patients were enrolled between August 2020 and August 2022 with median follow-up of 19.6 months. The pretreatment pathologic stages were high-grade (HG) T1 with carcinoma in situ (CIS; n = 7), HGT1 without CIS (n = 6), HGTa (n = 9), and CIS alone (n = 3). The 3-month complete response rate was 100% and recurrence-free survival at 12 months was 92%. Two patients with pretreatment HGT1 had HGT1 recurrences at 9 and 12 months. No patients progressed to T2 disease, underwent radical cystectomy, or had any radiographic evidence of progressive disease. Grade 1 AEs were common (23/25 patients) including hematuria, urinary frequency, urgency, and fatigue. Five patients (20%) experienced a grade 3 AE including hematuria and UTI.

Conclusions: In this single-arm phase 2 trial, GemDoce was well tolerated with promising efficacy for patients with BCG-naïve high-risk NMIBC.

Keywords: bladder cancer; docetaxel; gemcitabine; intravesical therapy.