Thursday, April 20, 2017

ContraVir’s Tenofovir Exalidex (TXL™) Antiviral Activity in Hepatitis B (HBV) Patients at the International Liver Congress (ILC)

Oral Presentation at EASL Highlights ContraVir’s Tenofovir Exalidex (TXL™) Antiviral Activity in Hepatitis B (HBV) Patients

EDISON, NJ, April 20, 2017 (GLOBE NEWSWIRE) -- ContraVir Pharmaceuticals, Inc. (NASDAQ:CTRV), a biopharmaceutical company focused on the development and commercialization of targeted antiviral therapies, today announced new data demonstrating clinical antiviral activity, as well as safety and pharmacokinetic (PK) data of tenofovir exalidex (TXL™). TXL™ is the Company’s proprietary liver targeting prodrug of the antiviral agent tenofovir for treating chronic hepatitis B virus (HBV), designed to offer equal or better HBV viral load reductions at doses lower than Viread® (TDF), a commercially available tenofovir prodrug. ContraVir is also focusing on optimizing drug delivery of TXL™ to improve bioavailability and enhance its pharmacological activity.

The data were presented today at The International Liver Congress™ (ILC) 2017, the annual meeting of the European Association for the Study of the Liver (EASL) in Amsterdam, The Netherlands. Notably, data from the presentation, “Pharmacokinetics, Safety and Antiviral Activity of TXL™, a Novel Prodrug of Tenofovir, Administered as Ascending Multiple Doses to Healthy Volunteers and HBV-Infected Subjects,” was chosen to be included in the best of viral hepatitis at ILC2017 debrief recording, where Professor Fabien Zoulim and Professor Heiner Wedemeyer will provide overviews on the latest in viral hepatitis research and patient management.

Dr. Tawesak Tanwandee, Associate Professor of Medicine and Head of the Division of Gastroenterology in the Department of Medicine at Siriraj Hospital, Mahidol University in Bangkok, Thailand and colleagues, conducted a trial in which they evaluated the effects of multiple ascending oral doses of TXL™ in healthy volunteers, as well as a second trial performed in HBV patients.

The first trial, a Phase 1b study, enrolled 50 healthy volunteers assigned to one of five sequential, ascending TXL™ dosing cohorts (5, 10, 25, 50, and 100 mg) where participants were randomized 8:2 to receive either TXL™ or placebo for 14 days.

The second Phase 2a trial evaluated the effects of multiple ascending oral doses of TXL™ (10, 25, 50, and 100 mg) in a proof-of-concept (POC) trial involving four cohorts of 12 HBV-infected subjects randomized 10:2 to receive either TXL™ or Viread® for 28 days.

Interim data in the POC study have demonstrated that a 100-mg dose of TXL™ resulted in a mean HBV viral load (Log10 IU/mL, 3.63 + 1.68) (mean + SD) compared to the mean viral load from a 300-mg dose of Viread® (Log10 IU/mL, 3.75 + 1.17) after 21 days of treatment. The reduction in viral load persisted for up to one month after cessation of treatment.

“These observed reductions in HBV viral load in patients support the further development of TXL™ as a promising new treatment for managing patients with chronic hepatitis B virus,” said Dr. Tanwandee, the lead investigator of both trials. “Continued development of TXL™ is also supported by the wide safety margin observed, as well as by its pharmacokinetic profile indicating dose linearity.”

The data demonstrated that TXL™, at all doses tested, resulted in substantially lower systemic circulating levels of tenofovir in the blood compared to Viread®. These results demonstrate the potential for TXL™ to reduce the risk of bone- and kidney-related toxicities associated with Viread®.

There were no serious adverse events (AEs) or discontinuations due to AEs, and other safety parameters (e.g., electrocardiograms, vital signs, safety laboratory results) showed no patterns, clusters, or relationship to the TXL™ dose.

“We now have clinical evidence that demonstrates 25 - 100 mg of TXL™ achieves viral load reductions that are similar to Viread® that is dosed at 300 mg. These reductions in viral load were accomplished with our first-generation formulation. We continue to enhance TXL™ by optimizing this first-generation product to further enhance drug delivery,” commented James Sapirstein, Chief Executive Officer at ContraVir. “With our early proof-of-concept principle now complete, we believe that our second-generation formulated TXL™ will give comparable reduction in viral load at lower doses compared to the doses of TXL™ reported in the present study.”

About TXL™
Tenofovir exalidex (TXL™) is a highly potent prodrug of the successful antiviral drug tenofovir. Its novel liver-targeting structure results in decreased circulating levels of tenofovir, lowering systemic exposure and thereby reducing the potential for renal side effects. ContraVir previously completed a Phase 1b dose-escalation trial of TXL™ in healthy volunteers, in which participants were treated at doses up to 100 mg per day for 14 days; in this trial, TXL™ displayed an excellent safety, tolerability, and drug distribution profile. Based on the agent’s best-in-class potential, ContraVir believes TXL™ can become the cornerstone of a curative combination therapy for hepatitis B.

TXL™ is a trademark of ContraVir Pharmaceuticals, Inc.

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