LBA24 CG0070, AN ONCOLYTIC ADENOVIRUS, FOR BCG-UNRESPONSIVE NON-MUSCLE-INVASIVE BLADDER CANCER (NMIBC): 12 MONTH INTERIM RESULTS FROM A MULTICENTER PHASE II TRIAL

Abstract

INTRODUCTION AND OBJECTIVES: CG'70 is a selective oncolytic adenovirus that exploits retinoblastoma pathway defects. We have previously demonstrated promising 6 month response using intravesical CG'70, but longer term efficacy is unknown. We performed 12 month evaluation of a phase II trial for CG'70 in patients with BCG-unresponsive NMIBC who refused cystectomy. METHODS: Sixty-seven patients with residual BCG-unresponsive high grade Ta, T1, or CIS ±Ta/T1 were accrued in this phase II single arm multicenter trial (NCT02365818). Patients were unable to achieve disease free state at 6 months after adequate BCG (BCG-refractory) or developed recurrence after complete response (CR) to BCG (BCG-relapsed). CR was defined as no disease on cystoscopy, cytology, and/or random biopsies. Six patients were excluded for withdrawn consents due to inadequate drug availability or subsequent therapy despite CR prior to 12 months. RESULTS: At interim analysis of 61 patients, overall 12 month CR was 30% (Figure 1). CIS-containing tumors had 27% 12 month CR (n=45) while pure Ta/T1 had 38% (n=16). No patients with T1/CIS or Ta/CIS had 12 month CR (n=6). BCG-refractory patients had 48% (n=25) 12 month CR, BCG-relapsed 19% (n=31), unknown 0% (n=5). Ten patients underwent cystectomy, of which 6 patients had muscle invasive disease. All 12 month treatment related adverse events (AEs) were Grade 1-3; immunologic AEs included influenza type illness (7%), fatigue (4%), and chills (1%). Five deaths were secondary to progressive urothelial carcinoma, esophageal carcinoma, lung carcinoma, and cardiac disease. CONCLUSIONS: Interim assessment of this phase II study demonstrates that intravesical CG'70 yielded an overall 30% complete response rate at 12 months for all patients with high-risk BCGunresponsive NMIBC and 48% for those with BCG-refractory disease.