MP43-02 CG0070, AN ONCOLYTIC ADENOVIRUS, FOR BCG-UNRESPONSIVE NON-MUSCLE-INVASIVE BLADDER CANCER (NMIBC): 18 MONTH FOLLOW-UP FROM A MULTICENTER PHASE II TRIAL

Abstract

INTRODUCTION AND OBJECTIVES: CG0070 is a selective oncolytic adenovirus that exploits retinoblastoma (Rb) pathway defects. We have previously shown promising interim results for this agent. We present mature results from a phase II trial for CG0070 in patients with BCG-unresponsive NMIBC who refused cystectomy. METHODS: Sixty-seven patients with residual BCGunresponsive 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. The primary endpoint was 18-month CR. Ten patients were excluded from analysis due to withdrawn consent or subsequent therapy despite continued CR prior to 18 months. RESULTS: On analysis of 57 patients, the overall 18-month CR rate was 23%. Among stage subsets, 18-month CR was 19% for CIScontaining tumors (n=43), 19% for pure CIS (n=27), and 36% for pure Ta, T1 or Ta/T1 disease (n=14). No patients with T1/CIS or T1/ Ta/CIS had 18-month CR (n=6). BCG-refractory patients had 35% (n=23) 18-month CR, BCG-relapsed 17% (n=29), unknown 0% (n=5). There was a subset of patients with durable CR (Figure 1). Eleven patients underwent cystectomy, of whom 6 patients had muscle invasive disease. All treatment related adverse events (AEs) were Grade 1-3; immunologic AEs included influenza type illness (7%), fatigue (4%), and chills (1%). Six deaths were secondary to progressive urothelial carcinoma, esophageal carcinoma, lung carcinoma, and cardiac disease. CONCLUSIONS: This phase II study demonstrates that in a high-risk BCG-unresponsive NMIBC population, intravesical CG0070 yielded overall 44%, 30%, and 23% complete response rates at 6, 12, and 18 months, respectively. Rb and checkpoint biomarker analysis is pending to attempt prediction of which patients have durable response to this agent. (Figure Presented).