Bacillus Calmette-Guérin (BCG) in combination with PANVAC™ vs. BCG alone in adults with high-grade BCG-refractory non-muscle-invasive bladder cancer.

PURPOSE: We postulated that PANVAC™, a recombinant poxviral vector vaccine, could enhance the immunologic and clinical response to an additional induction course of bacillus Calmette-Guérin (BCG) in patients with recurrent high-grade non-muscle-invasive bladder cancer (NMIBC).

METHODS

This was a randomized, open-label, prospective, phase II study in subjects with high-grade NMIBC who had failed at least 1 induction course of intravesical BCG. Patients were randomized to either BCG alone or BCG+PANVAC. All subjects received intravesical BCG for 6 weeks. Patients in the combination arm also received priming and booster doses of PANVAC. The primary endpoint was recurrence-free survival. Secondary endpoints included progression-free survival and radical cystectomy-free survival. We also evaluated exploratory secondary immunological response endpoints.

RESULTS

Our study concluded based on preplanned futility analysis. Overall, 32 patients were enrolled; 2 withdrew. Thirty patients (15/arm) were analyzed; 5 (33.3%) in the BCG-alone arm and 5 (33.3%) in the BCG+PANVAC arm met criteria for BCG- unresponsive disease. 12-month recurrence-free survival was 53.3% for the BCG-alone arm and 40% for the BCG+PANVAC arm. Overall recurrence rate at any time point was 73.3% at a median of 10.8 months, for an overall recurrence rate of 66.7% in the BCG-alone arm and 80% in the BCG+PANVAC arm. There was no difference in median recurrence-free survival or progression-free survival.

CONCLUSIONS

This phase II study demonstrated no improvement in recurrence-free survival with BCG+PANVAC compared to BCG alone in patients with NMIBC who failed to respond to intravesical BCG.