Salvage therapy for BCG failure with intravesical sequential gemcitabine and docetaxel in patients with recurrent NMIBC.

Introduction: Bacillus Calmette-Guérin (BCG) failure occurs in approximately 40% of patients with non-muscle-invasive bladder cancer (NMIBC) within two years. We describe our institutional experience with sequential intravesical gemcitabine and docetaxel (gem/doce) as salvage therapy post-BCG failure in patients who were not candidates for or declined radical cystectomy (RC).

Methods: We retrospectively reviewed NMIBC patients with BCG failure who received gem/doce from April 2019 through October 2022 at the CHU de Québec-Université Laval. Patients received at least five weekly intravesical instillations according to published protocols. Patients who responded to gem/doce had maintenance instillations monthly for up to two years. Primary outcome was progression-free survival (PFS). Secondary outcomes included recurrence-free survival (RFS), cystectomy-free survival (CFS), cancer-specific survival (CSS), overall survival (OS), and treatment adverse events. Survival probabilities were estimated using the Kaplan-Meier method from the first gem/doce instillation.

Results: Thirty-five patients with a median age of 78 years old were included in the study. The median followup time was 21 months (interquartile range 10-29). More than 25% of patients received two or more prior BCG induction treatments. Overall and MIBC PFS estimates at one year were 85% and 88%, and at two years, 60% and 70%, respectively. Adverse events occurred in 37% of the patients, but only two patients didn't complete the treatment due to intolerance. Three patients underwent RC due to cancer progression. OS was 94% at two years.

Conclusions: With 60% of PFS at two years, gem/doce appears to be a safe and well-tolerated option for BCG failure patients. Further studies are needed to justify widespread use.