An Open Label, Single-arm, Phase 2 Study of Neoadjuvant Pembrolizumab (MK-3475) Before Cystectomy for Patients With Muscle-invasive Urothelial Bladder Cancer.

Detailed Summary

Patients with T2-T4a N0 urothelial bladder carcinoma (UBC) with residual disease after transurethral resection of the bladder (TURB, surgical opinion, cystoscopy or radiological presence) will receive 3 cycles of pembrolizumab (MK-3475) at the dose of 200mg 3 weekly prior to surgery (radical cystectomy). Cystectomy will be planned to be done within 3 weeks of the last dose (accounting for a total of 9 weeks). Computed tomography (CT) scan and fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan will be done during screening and before surgery. After cystectomy, patients with the evidence of pathologic stage T3-4 (pT3-4) and/or pathologically node-positive disease will be managed according to local guidelines. Further anti programmed-death (PD)-1 or anti PD-ligand 1 (PD-L1) therapy will not be given post-operatively. PD-L1 status will be centralized and assessed on TURB specimen using an anti-PD-L1 antibody (Ab) and a prototype immunohistochemical (IHC) assay. PD-L1 positivity will be defined as any staining in the stroma or in ≥1% of tumor cells. Pathologic complete response (pCR) is the primary endpoint. All patients enrolled who receive at least 1 cycle of study drug will be includes in the intention-to-treat (ITT) analysis. The alternative hypothesis (H1) is pCR ≥20% and null hypothesis (H0) pCR≤10%. A 2-stage design will be used to estimate the number of pts required. Out of 90 pts overall, with the first stage of 49 pts, ≥6 pCR will be required in the first stage, and ≥13 pCR in the whole study population (80% power and a 2-sided test of significance at the 10% level). Correlative research on tissue/blood samples will include immune-cell profiling in tumor and blood during Pembrolizumab, cytokine assessment, and molecular profiling of tumor samples.

Study Details

Timeline

Interventions