(UroToday.com) At the 2021 European Association of Urology annual meeting, Vikram Narayan, discussed results of additional analysis assessing anti-adenovirus antibody response correlating with efficacy among patients in the phase III trial assessing nadofaragene firadenovec in patients with BCG unresponsive non-muscle invasive bladder cancer (NMIBC). This study was recently published in Lancet Oncology1. Nadofaragene firadenovec is a non-replicating recombinant type-5 adenovirus vector-based gene therapy that delivers a copy of the human IFNα2b gene. Adenoviruses provide short-term, high but transient expression of the gene of interest in a relatively broad range of host cells. The Phase III trial of nadofaragene firadenovec for BCG unresponsive NMIBC was a multi-center study to investigate the safety and efficacy of intravesical nadofaragene firadenovec 75 mL once every 3 months in 157 patients with high-grade, BCG-unresponsive NMIBC. Cytology and cystoscopy (with biopsy if clinically indicated) were performed at 3, 6, and 9 months to evaluate for recurrence of high-grade disease. At 12 months, all patients underwent urine cytology, cystoscopy, and mandatory biopsy. Patients free from high-grade recurrence were eligible for retreatment at 3-month intervals while they remained high-grade recurrence-free. The study met its primary endpoint with 53.4% of patients with CIS ±Ta/T1 achieving a complete response, all by 3 months, including 43.6% of these patients remaining free of high-grade recurrence at 15 months.