ContraVir Pharmaceuticals

About ContraVir

ContraVir is a biopharmaceutical company focused on the development and commercialization of targeted antiviral therapies with three candidates in the pipeline. Two of its antiviral candidates for treating hepatitis B include Phase 2a clinical candidate TXL™ (formerly CMX157), a novel, highly potent analog of the successful antiviral drug tenofovir that has demonstrated the potential for low, once a day dosing compared to Viread® and decreased systemic exposure, thereby potentially reducing renal and bone side effects; and CRV431, a next generation cyclophilin inhibitor with a unique structure that increases its potency and selective index against hepatitis B virus. ContraVir’s third candidate and lead clinical drug, Valnivudine™ (formerly FV-100), is an orally available nucleoside analogue prodrug that is being developed for the treatment of herpes zoster, or shingles, which is currently in Phase 3 clinical development. In addition to direct antiviral activity, Valnivudine™ has demonstrated the potential to reduce the incidence of debilitating shingles-associated pain known as post-herpetic neuralgia (PHN) in a Phase 2 clinical study.

Pipeline of Drug Candidates

ContraVir Pharmaceuticals has two mid-to-late stage clinical assets and actively seeks to expand its pipeline of targeted antiviral therapies. Explore our Pipeline >>



Having demonstrated favorable safety and efficacy in Phase 1 trials, ContraVir is developing TXL™ (formerly CMX157) for Hepatitis B in Phase 2 clinical studies.


CRV431 is advancing into IND-enabling studies in preparation for potentially entering the clinic in 2017.


ContraVir is conducting a pivotal Phase 3 trial to further explore Valnivudine’s™ potential to reduce the incidence of shingles pain and post-herpetic neuralgia.

Hepatitis B

Hepatitis B is an infectious disease caused by the hepatitis B virus (“HBV”). Currently there are about 350 million chronic HBV patients worldwide. The primary goal of treating chronic hepatitis B is to suppress HBV replication and induce liver disease remission prior to the onset of cirrhosis and hepatocellular carcinoma, which are often the result of chronic HBV infection if not managed. Experts currently believe combination therapy is the best approach to a potential cure for HBV. Learn more about Hepatitis B >>

Shingles and Shingles Pain

Herpes zoster, also commonly known as shingles, is a neurological disorder caused by the reactivation of varicella zoster virus, the same virus that causes chickenpox. Based on recent research and publications, we estimate that there are over 4 million cases of shingles in the U.S., Europe and Japan each year, of which more than half occur in the U.S. Shingles-associated pain that persists more than three months is generally referred to as Postherpetic Neuralgia (“PHN”), which is the most common and clinically relevant complication of shingles. Approximately 15-20% of all shingles patients experience PHN, although the incidence of PHN is more prevalent in patients over 50 years of age. Learn about Shingles >>

U.S. Sales of Approved HBV Drugs (2014)

ContraVir is developing TXL™ for Hepatitis B in Phase 2 clinical studies. TXL™ is a novel lipid acyclic nucleoside phosphonate that delivers high intracellular concentrations of the active antiviral agent of tenofovir, marketed by Gilead as Viread®. TXL™’s novel structure results in decreased circulating levels of tenofovir, lowering systemic exposure and thereby reducing the potential for renal side effects. TXL™ has completed a Phase 1 clinical trial in healthy volunteers, demonstrating a favorable safety, tolerability and drug distribution profile. Learn more about TXL™ >>

Potential Advantages of TXL™ over Tenofovir (TFV)
  • Increased efficacy by boosting bioavailability
  • Takes advantage of natural lipid uptake mechanisms
  • Decreased renal toxicity by reduced circulating TFV
  • 97-fold more active against HBV in vitro

ContraVir is developing CRV431 for treating hepatitis B and is currently preparing to enter IND-enabling studies based on strong preclinical data. CRV431 is a next-generation cyclophilin inhibitor designed specifically to optimize potency and selectivity against HBV. It works by disrupting the viral life cycle at multiple points. Learn more about CRV431 >>

Potential Advantages of CRV431
  • Best-in-class potency and selective index against HBV
  • Interrupts HBV at multiple points, limiting replication and potential resistance
  • Blocks HBV entry into liver cells and suppresses HBsAg and HBeAg in vitro
  • Reduces HBV DNA without toxicity; prevents liver fibrosis in vivo


Based on our clinical findings, we believe Valnivudine™ is well positioned as a fast-acting, low-dose, once-daily, oral antiviral agent for the treatment of herpes zoster, or shingles, which is an infection caused by the reactivation of varicella zoster (chicken pox) virus. In addition to direct antiviral activity, Valnivudine™ has demonstrated the potential to reduce the incidence, severity, and duration of debilitating shingles-associated pain, known as post-herpetic neuralgia, or PHN. Learn more about Valnivudine™ >>


  • Conducting a Phase 3 clinical study
  • Well-tolerated with demonstrated reduction in PHN pain in Phase 2 trials
  • Potential for more convenient dosing vs. current standard of care (once daily versus 3-5x daily)
  • No dose adjustment required for patients with renal insufficiency
  • Strong IP position with composition of matter protection to 2027
Potential Advantages of Valnivudine™ Over Marketed Shingles Therapies

Pharmacokinetic data from completed Phase 1 and 2 clinical trials suggest that Valnivudine™ has the potential to demonstrate antiviral activity when dosed orally once-a-day at significantly lower blood levels than acyclovir, valacyclovir, and famciclovir, the FDA-approved drugs used for the treatment of shingles.

Learn about the Valnivudine™ Clinical Trial at >>

The Leadership Team

The ContraVir team brings significant background in the development and commercialization of targeted antiviral therapies.

Chief Executive Officer

Chief Financial Officer

Chief Medical Officer

Senior VP, Drug Development