CMX157 presents better safety profile against HBV vs. Viread

ContraVir Pharmaceuticals, Inc. released preliminary data that showed CMX157, a potential therapeutic for hepatitis B virus infection, was more active against the infection compared with Viread, according to a press release.

CMX157, a novel lipid acyclic nucleoside phosphonate, “is up to 60-fold more active against HBV and more than 200-fold more active against all major HIV subtypes in vitro” compared with Viread (tenofovir disoproxil fumarate [DF], Gilead Sciences), according to the release. In a phase 1 clinical trial among healthy volunteers, CMX157 showed a favorable safety, tolerability and drug distribution profile. CMX157 decreased circulating levels of tenofovir, lowered systemic exposure and reduced the potential for renal and bone side effects.

According to ContraVir, this was due to the design of CMX157, which distinguishes it from tenofovir DF. The “enhanced absorption technology” of CMX157 could potentially lower systemic exposure to the liver compared to tenofovir DF. This in turn would result in reduced off-target toxicity, according to the release.

Current studies are underway to investigate the efficiency of CMX157 prodrug conversion to tenofovir diphosphate and are also assessing the in-vitro safety profile of CMX157, according to the release.

ContraVir plans to submit an investigational new drug application for CMX157 to treat HBV before the end of 2015. In addition, a phase 2 clinical trial is planned for 2016.

In February, Chimerix Inc., a licensing partner of ContraVir Pharmaceuticals, received a Notice of Allowance from the United States Patent and Trademark Office for an extended patent life on its “Nucleoside Phosphonate Salts” patent, which includes CMX157.