ElectroMotive drug administration (EMDA) of Mitomycin C as first-line salvage therapy in high risk "bCG failure" non muscle invasive bladder cancer: 3 years follow-up outcomes

Background: In case of high grade non-muscle invasive bladder cancer (HG-NMIBC), intravesical BCG represents the first-line treatment; despite the "gold" standard therapy, up to 50% of patients relapse, needing radical cystectomy. Hence, alternative therapeutic strategies have been developed. The aim of the study was to evaluate a first-line salvage treatment with EMDA®-MMC in patients with HGNMIBC unresponsive to BCG. Methods: We carried out a prospective, single-center, single-arm Phase II study in order to evaluate the efficacy (in terms of recurrence and progression) and the safety of the EMDA®-MMC treatment in 26 (21 male, 5 female) consecutive patients with "BCG refractory" HGNMIBC on a 3 years follow-up. EMDA®-MMC treatment consisted of 40 mg of MMC diluted in 100 ml of sterile water retained in the bladder for 30 min with 20 mA pulsed electric current. EMDA®-MMC regimen consisted of an induction course of 6 weekly instillations followed by a maintenance course of 6 monthly instillations. Follow-up was performed with systematic mapping biopsies of the bladder (with sampling in the prostatic urethra for men), voiding and washing urinary cytology, radiological study of the upper urinary tract. We performed Survival Kaplan-Meier curves and Log-rank test in order to analyze high grade disease-free survival. Results: At the end of follow-up, 16 patients (61.5%) preserved their native bladder; 10 patients (38.4%) underwent radical cystectomy, in 6 patients (23.1%) for recurrent HGNMIBC and in 4 patients (15.4%) for progression to muscle-invasive disease. At the end of follow-up, stratifying patients based on TNM classification (TaG3, T1G3, Cis, TaT1G3 + Cis), disease-free rates were 75, 71.4, 50 and 25%, respectively; survival curves showed statistically significant differences (p value < 0.05). Regarding toxicity, we reported severe adverse systemic event of hypersensitivity to the MMC in 3 patients (11.5%), and local side effects in 6 patients (26.1%). Conclusions: In the field of alternative strategies to radical cystectomy, the EMDA®-MMC could be considered safe and effective in high-risk NMIBC unresponsive to BCG, as a "bladder sparing" therapy in selected patients. Multicenter studies with a larger number of patients and a longer follow-up might confirm our preliminary results.