Efficacy of Durvalumab in Non-muscle-invasive Bladder Cancer
Research Hypothesis Approximately 75% of patients with bladder cancer (BC) present with a disease confined to the mucosa (stage Ta, CIS) or submucosa (stage T1) (non-muscle invasive BC [NMIBC]). For high grade NMIBC, i.e. TaG3, T1G3 and CIS, intravesical bacillus Calmette-Guérin (BCG) immunotherapy is the treatment of choice, given that it prevents recurrence and reduces the odds of progression to MIBC. However, since initial BCG therapy fails in approximately 40% of patients over a 2-year period, new treatment options for these patients are of utmost importance. In that field of research durvalumab, a human monoclonal antibody that binds programmed cell death ligand-1 (PD-L1), demonstrated meaningful clinical activity as well as manageable safety profile in PD-L1-positive patients with BC, many of whom were heavily pretreated. Certain studies using systemic administration of anti-PD1 agents for BCG refractory NMIBC are ongoing. Nevertheless, intravesical administration may be advantageous, since selective bladder tumor uptake of monoclonal antibodies following intravesical administration, while this method results in negligible absorption in the circulation and, therefore, minimal risk of systemic toxicity. This notion is supported by the findings of a recent study of intravesical administration of recombinant adenovirus-mediated interferon-?2b gene therapy (rAd-IFN?), No rAd-IFN? DNA was detected in the blood. Furthermore, no systemic toxicity was reported in a phase II study using the same agent. The investigators, therefore, propose a phase II study of intravesical administration of durvalumab in patients with BCG refractory NMIBC. Since no safety or efficacy data specifically on intravesical administration of durvalumab exist, a run-in part will precede the main phase II, in order to confirm safety of the procedure and to reject a futility hypothesis, as described in the following sections of the protocol. Correlative studies of potential biomarkers in tumor tissue before and after durvalumab instillation are also proposed.
Start: November 2018