The Chemoablative Effect of VesiGel® Instillation in Patients with NMIBC – Preliminary Results

AUA poster presentation, Saturday, May 7, 2016 8:00 AM-10:00 AM

The Chemoablative Effect of VesiGel® Instillation in Patients with NMIBC – Preliminary Results
Boris Friedman*, Yoram Dekel, Haifa, Israel, Andrea Tubaro, Rome, Italy, Ami Sidi, Benjamin Shalva, Holon, Israel, Jack Baniel, Daniel Kedar, Petach Tikvah, Israel, Lorenzo Colombo, Milan, Italy, Dov Engelshtein, Naharya, Israel, Edi Fridman, Tel Aviv, Israel, Ifat Klein, Michal Jeshurun, Baruch Nerotski, Dima Zolotrayov, Nadav Malchi, Raanana, Israel, Joan Palou Redorta, Barcelona, Spain, Gregory Wirth, Geneva, Switzerland, Ilan Leibovitch, Kfar Saba, Israel, Fred Witjes, Nijmegen, Netherlands

Abstract: PD11-05
Introduction and Objectives
The standard of care for treating NMIBC patients is TURBT and intravesical instillations. A limitation of this treatment is the inability to completely resect all existing tumors and the risk of cells reseeding during TURB. VesiGel, a novel Mitomycin C (MMC) formulation in a thermoreversible hydrogel (TC-3), is fluid when chilled and solidifies at body temperature. Prior to treatment, the chilled TC-3 is mixed with MMC and instilled into the bladder where it solidifies and serves as a sustained release MMC (~6 hr). This study aims to evaluate VesiGel as a chemoablation product for low grade (LG) NMIBC.

Methods
Patients (N=55) with LG NMIBC were enrolled and underwent an initial diagnostic cystoscopy. The study consisted of 3 groups, Group A: VesiGel 40mg (N=17), Group B: VesiGel 80mg (N=16), Group C: MMC 40mg in water (N=22). VesiGel was administered at 64mL, while MMC in water was administered at 40mL, all for 6 weekly instillations. Response was evaluated 2 weeks after the last instillation via cystoscopy and histology. All patients are followed for 12 months after last treatment.

Results
Possible adverse reactions (AR) associated with VesiGel are: dysuria (47.6%), pruritus (14.3%), drug hypersensitivity (7.1%) and penile edema (4.8%). Most of the events were transient and resolved despite continued therapy. Overall, the incidence of ARs reported of VesiGel appears to be low and MMC-related. Comparison between the VesiGel and MMC in water groups demonstrates an equal level of allergic reactions, while the VesiGel groups demonstrate a higher rate of dysuria (~40%) compared to MMC in water (~13%). Of the 17 patients in Group A, 35.3% had complete response (CR), 35.3% had partial response (PR) and 29.4% had no response (NR). Of the 16 patients in Group B, 87.5% had CR, 12.5% had PR, and 0 had NR. Of the 22 patients in Group C, 63.6% had CR, 22.7% had PR, 9.1% had NR and 4.5% (N=1) had progression. The success rate of patients with one or more tumors with diameter of <1cm were 50.0, 87.5 and 66.6% in group A, B and C, respectively. The success rate of patients with large tumors (over 1 cm) were 0, 87.5 and 55.5%, respectively. Recruitment and long-term follow-up are ongoing.

Conclusions
These preliminary results provide an initial indication of the ablative effect of VesiGel (80mg) compared to MMC 40mg. VesiGel (80mg) was advantageous regardless of tumor size, whereas MMC in WFI was less effective in larger tumors. The use of VesiGel enables safe and effective chemoablative treatment using higher dosages of MMC in the bladder.

Date & Time: May 7, 2016 8:00 AM-10:00 AM
Session Title: Bladder Cancer: Non-Invasive II
Sources of Funding: UroGen Pharma

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