Urinary bother, Urinalysis, and Two-Year Efficacy Follow-Up Results of Phase I Trial of Intravesical Bacillus Calmette-Guérin Combined with Intravenous Pembrolizumab in Recurrent or Persistent High-Grade Non-Muscle-Invasive Bladder Cancer after Previous Bacillus Calmette-Guérin Treatment.

Objective: To report urinary bother, urinalysis changes, disease-free survival (DFS), and overall survival (OS) over 2 years for subjects enrolled in a phase I dose-escalation trial (NCT02324582) of intravesical Bacillus Calmette-Guérin (BCG) in combination with systemic pembrolizumab for recurrent or persistent high-grade non-muscle invasive bladder cancer (HGNMIBC).

Methods: Eighteen patients consented to the study. Five were screen failures. Clinical activity was determined using cystoscopy and cytology with a biopsy of suspicious lesions. Urinalysis and International Prostate symptom score were assessed at pre-treatment, Week 10 (during combined BCG and pembrolizumab treatment), and 3 and 6 months from treatment completion. IPSS was analyzed using a mixed-model repeated measures analysis. A Chi-square test was used to compare urinalysis results at each interval.

Results: The pathologic disease stage after restaging transurethral resection and before treatment was pTa in 6 (46.2%), CIS in 6 (46.2%), and pT1 in 1 (7.7%). There was no increase in reported urinary bother throughout treatment. Quality of life measurements demonstrated no change in subjective burden. On urinalysis, we did not observe significant differences at 3 months compared to baseline evaluation. At 12 months, the DFS and OS were 69.23% and 92.31%, respectively. At 24 months, the DFS and OS were 38.46% and 92.31%, respectively.

Conclusions: Treatment with BCG combined with intravenous pembrolizumab is not showing increased urinary bother or adverse urinalysis changes. Two-year response data is promising and await confirmation in the phase III study (Keynote 676).