Efficacy and Safety Evaluation of EN3348 (Mycobacterial Cell Wall-DNA Complex [MCC]) as Compared With Mitomycin C in the Intravesical Treatment of Subjects With BCG Recurrent/Refractory Non-muscle Invasive Bladder Cancer

This is a phase 3 randomized, active-controlled, open-label, multicenter study that will be conducted in approximately 120 investigational sites worldwide. Subjects with either recurrent or refractory NMIBC (Ta high grade, T1 low or high grade, CIS) will be eligible for participation in this study. Refractory disease is defined as evidence of persistent high grade bladder cancer (Ta HG, T1, and/or CIS) at least 6 months from the start of a full induction course of BCG with or without maintenance/re-treatment at 3 months. Recurrent disease is defined as reappearance of disease after achieving a tumor-free status by 6 months following a full induction course of BCG with or without maintenance/re-treatment at 3 months. Subjects with recurrent disease must have recurred within 18 months following the last dose of BCG. Approximately 450 subjects will be randomized. The primary objective of this study is to evaluate the efficacy of intravesical EN3348 as compared with mitomycin C in the treatment of subjects with recurrent or refractory NMIBC. The secondary objective is to evaluate the safety of EN3348 as compared with mitomycin C in the treatment of subjects with BCG recurrent or refractory NMIBC. This study will consist of 4 phases: Screening, Induction, Maintenance and Follow-Up and will be conducted over 3 years.