Modern Immunotherapy in BCG-Unresponsive, BCG-Relapsing and High Risk BCG-Naive Non-Muscle Invasive Urothelial Carcinoma of the Bladder

Upon successful screening and registration, enrollment to durvalumab monotherapy (cohort 1) will begin. If DLT criteria outlined in the protocol are exceeded with durvalumab monotherapy (cohort 1), the study will close. Provided the safety of durvalumab monotherapy is established, enrollment to combination regimen cohorts will proceed. Cohorts will simultaneously enroll in parallel to each other with patients assigned to cohorts based on patient slot availability and study site choice of radiation arm participation. Patient assignment to future phase 1 arms would proceed similarly. Within BCG-containing cohorts, treatment will begin at full-dose BCG. If DLT criteria outlined in Section 5.1.4 are exceeded with full-dose BCG, a one level dose reduction of BCG will be implemented. If DLT criteria outlined in Section 5.1.4 are exceeded with reduced-dose BCG, the BCG-containing cohort will not proceed to Phase 2 of the study. Similarly, if DLT criteria outlined in Section 5.1.4 are exceeded within non-BCG containing cohorts, the non-BCG containing cohort will not proceed to phase 2 of the study. Due to the prolonged half-life of antibody therapies, no dose adjustments are planned for durvalumab in any of the cohorts.