Phase I Trial of Intravesical Recombinant Adenovirus-Mediated Interferon-α2b Formulated in Syn3 for BCG failures in Non-Muscle-Invasive Bladder Cancer

Abstract

Purpose

A Phase l trial of intravesical recombinant adenovirus-mediated interferon-α2b gene therapy (rAd-IFNα) formulated with the excipient SCH Syn3 was conducted in patients with non-muscle invasive bladder cancer (NMIBC) who recurred after Bacillus Calmette-Guerin (BCG). The primary objective was to determine the safety of rAd-IFNα/Syn3; secondary endpoints were to demonstrate effective rAd-IFNα gene expression and preliminary evidence of clinical activity at three months.

Patients and Methods

Seventeen patients with recurrent NMIBC after BCG were enrolled. A single treatment of rAd-IFNα (3x109 to 3x1011 particles/mL) formulated with the excipient Syn3 was administered. Patient safety was evaluated for ≥12 weeks. Efficacy of gene transfer was determined by urine IFNα protein concentrations. Preliminary drug efficacy was determined at 3 months.

Results

Intravesical rAd-IFNα/Syn3 was well tolerated as no dose limiting toxicity (DLT) was encountered. Urgency was the most common adverse event and all were grade 1 or 2. rAd-IFNα DNA was not detected in the blood, however, transient low serum IFNα and Syn3 levels were measured. High and prolonged dose-related urine IFNα levels were achieved with the initial treatment. Of the 14 patients treated at doses ≥ 1010 particles/mL with detectable urine IFNα, 6 (43%) experienced a complete response at 3 months and 2 remained disease free at 29.0 and 39.2 months respectively.

Conclusion

Intravesical rAd-IFNα/Syn3 was well tolerated with no DLT encountered. Dose dependent urinary IFNα concentrations confirmed efficient gene transfer and expression. Intravesical rAd-IFNα/Syn3 demonstrated clinical activity in NMIBC recurring after BCG.

http://www.jurology.com/article/S0022-5347(13)03676-8/abstract