Dinney, Colin P.

442 Background: Patients (pts) with BCG-unresponsive NMIBC are at significant risk for disease recurrence and progression. While cystectomy can be curative, many such pts are unwilling or unable given the attendant morbidity of surgery. To date, effective salvage intravesical therapies in this setting remain lacking. Nadofaragene firadenovec is a novel intravesical gene-mediated therapy that delivers the human IFNα2b gene resulting in IFNα2b expression that provided durable responses in a previous Phase 2 trial. Herein, we report the results from a follow-up Phase III trial of this agent for pts with BCG unresponsive NMIBC. Methods: This multicenter, open-label Phase 3 study investigated nadofaragene for high-grade NMIBC (CIS ± Ta/T1, or Ta/T1 alone) unresponsive to BCG. Nadofaragene (3X1011 vp/mL [75 mL]) was administered once every 3 months for up 4 doses in the initial 12 months, with additional dosing at the investigator’s discretion. The primary endpoint was complete response (CR) at any time in pts with carcinoma in situ (CIS). Results: A total of 157 pts (safety population, n=157; efficacy population, n=151) were enrolled. Among pts with CIS (n=103), 55 (53.4%) (95% CI, 43.3-63.3) achieved CR, all by month 3 after treatment. Of these 55 CIS CR pts, 25 (45.5%) remained free of high-grade recurrence at month 12, confirmed on protocol-mandated biopsy. For pts with HG Ta/T1 alone, 35 (72.9%) and 21 (43.8%) were free from recurrence at 3 and 12mos, respectively. Most treatment-emergent adverse events (TEAEs) were transient in nature: instillation site discharge 33.1%; fatigue 23.6%; bladder spasm 19.7%; micturition urgency 17.8%; hematuria 16.6%. There were 2 Gr4 TEAEs (sepsis and anaphylactic reaction, neither related to study drug) and no Gr5 TEAEs. Conclusions: Nadofaragene achieved CR in 53.4% of pts with BCG-unresponsive CIS, and was well tolerated. Responses were noted early and remained durable to one year. These data represent a potentially significant management advancement for a historically difficult to treat disease state. Clinical trial information: NCT02773849.

Purpose Many patients with high-risk non–muscle-invasive bladder cancer (NMIBC) are either refractory to bacillus Calmette-Guerin (BCG) treatment or may experience disease relapse. We assessed the efficacy and safety of recombinant adenovirus interferon alfa with Syn3 (rAd–IFNα/Syn3), a replication-deficient recombinant adenovirus gene transfer vector, for patients with high-grade (HG) BCG-refractory or relapsed NMIBC. Methods In this open-label, multicenter (n = 13), parallel-arm, phase II study ( ClinicalTrials.gov identifier: NCT01687244), 43 patients with HG BCG-refractory or relapsed NMIBC received intravesical rAd–IFNα/Syn3 (randomly assigned 1:1 to 1 × 10 11 viral particles (vp)/mL or 3 × 10 11 vp/mL). Patients who responded at months 3, 6, and 9 were retreated at months 4, 7, and 10. The primary end point was 12-month HG recurrence-free survival (RFS). All patients who received at least one dose were included in efficacy and safety analyses. Results Forty patients received rAd–IFNα/Syn3 (1 × 10 11 vp/mL, n = 21; 3 × 10 11 vp/mL, n = 19) between November 5, 2012, and April 8, 2015. Fourteen patients (35.0%; 90% CI, 22.6% to 49.2%) remained free of HG recurrence 12 months after initial treatment. Comparable 12-month HG RFS was noted for both doses. Of these 14 patients, two experienced recurrence at 21 and 28 months, respectively, after treatment initiation, and one died as a result of an upper tract tumor at 17 months without a recurrence. rAd–IFNα/Syn3 was well tolerated; no grade four or five adverse events (AEs) occurred, and no patient discontinued treatment because of an adverse event. The most frequently reported drug-related AEs were micturition urgency (n = 16; 40%), dysuria (n = 16; 40%), fatigue (n = 13; 32.5%), pollakiuria (n = 11; 28%), and hematuria and nocturia (n = 10 each; 25%). Conclusion rAd—IFNα/Syn3 was well tolerated. It demonstrated promising efficacy for patients with HG NMIBC after BCG therapy who were unable or unwilling to undergo radical cystectomy.

279 Background: While bacillus Calmette-Guérin (BCG) is the most effective intravesical treatment for reducing recurrence and progression for high-risk non-muscle invasive bladder cancer (NMIBC), many patients are either refractory to treatment or relapse. We assessed the efficacy and safety of rAd-IFNα/Syn 3 (Instiladrin, FKD Finland), a replication deficient recombinant adenovirus gene transfer vector, for patients with high-grade (HG) BCG refractory or relapsed NMIBC. Methods: In this open-label, US multicenter (n=13), parallel-arm Phase II study (NCT01687244), 43 patients with HG BCG refractory or relapsed NMIBC were randomized 1:1 to receive intravesical rAd-IFNα/Syn3 at 1x1011 or 3x1011viral particles/mL. Patients responding at months 3, 6, and 9 were re-treated at months 4, 7, and 10. Most patients (n=21) had a primary tumor classification of carcinoma in situ (CIS); 9 had both CIS and Ta/T1 disease and 10 had Ta/T1 disease alone. The primary endpoint was 12-month HG recurrence-free survival (RFS). All patients receiving at least one dose were included in efficacy and safety analyses. Results: Forty patients received rAd-IFNα/Syn3 (1 x 1011 vp/mL: n=21; 3 x 1011vp/mL: n=19) between November 2012 and April 2015. Fourteen patients (35.0%; 90% CI 22.6%, 49.2%) remained free of HG tumor recurrence 12 months after initial treatment. Comparable 12 month HG RFS was noted between dosage arms, as well as between patients with refractory and relapsed NMIBC. Interestingly, the 12 month HG recurrence-free survival for patients with Ta/T1-only disease was 50% (5/10). rAd-IFNα/Syn3 was well-tolerated, with no Grade 5 adverse events (AEs), one Grade 4 AE (COPD; unrelated to treatment), and no patient discontinuing treatment due to an adverse event. The most frequently reported AEs were micturition urgency (n=16), dysuria and pollakiuria (n=13 each), fatigue (n=9), and nocturia (n=10). Conclusions: rAd-IFNα/Syn3 was well tolerated and demonstrated promising efficacy for patients with HG NMIBC after BCG therapy who are unable or unwilling to undergo radical cystectomy. A phase III trial utilizing this novel agent is ongoing. Clinical trial information: 01687244.