Sequential administration of Bacillus Calmette-Guerin (BCG) and Electromotive Drug Administration (EMDA) of mitomycin C (MMC) for the treatment of high-grade nonmuscle invasive bladder cancer after BCG failure

Background: There is a need for effective nonsurgical treatment options in patients with nonmuscle invasive bladder cancer (NMIBC) in whom Bacillus Calmette-Guerin (BCG) therapy has failed.

Objective: We aimed to determine the efficacy of Electromotive Drug Administration (EMDA) of mitomycin C (MMC) with NMIBC after BCG failure.

Design, setting, and participants: A retrospective review of 26 NMIBC patients in whom BCG therapy failed who received BCG/EMDA-MMC between 2013 and 2017 was performed. All but 4 patients fulfilled the FDA criteria for BCG unresponsive disease. Progression and recurrence-free survival (RFS)were calculated using Kaplan-Meier curves. Progression was defined as development of muscle invasive disease, presence of metastasis on imaging or treatment. We used FDA-defined criteria as complete response (CR) for single-arm trials of BCG-unresponsive patients.

Results and limitations: Twenty-six patients were included. Initial pathology was carcinoma in situ (CIS) in 53.8% (14/26), pT1 in 34.6% (9/26), and pTa HG disease in 11.6% (3/26). Twelve of 26 patients progressed (46.2%). Following BCG/EMDA-MMC treatment, progression-free survival rates were 58.3% (95% confidence interval [CI] 41.1-82.1) at 1 year and 48.9% (95% CI 48.9) at 2 years from the date of induction of BCG/EMDA-MMC, respectively. RFS was 41.9% (95% CI 25.9-67.8) at 1 year and 27.2% (95% CI 13.6-54.4) at 2 years. CR at 6, 12, and 18 months was observed in 16 (61.5%), 11 (44.0%), and 7 patients (30.4%), respectively. Side effects included dysuria (19.2%), hematuria (19.2%), and frequency (11.5%). Three patients were admitted for side effects but managed conservatively. Four patients (15.4%) died of bladder cancer over the course of the study.

Conclusions: EMDA-MMC BCG represents a viable option in patients with BCG unresponsive NMIBC with close to 50% progression-free survival at 2 years. However, these patients have a high risk of death from bladder cancer (15% in our cohort at 2 years) thus warranting extremely close surveillance.