ContraVir Evaluated the Anti-viral Power of CMX157 versus the Standard Treatment for Hepatitis B

ContraVir Pharmaceuticals issued a press release statement that they are pursuing the positive recommendation of Data Safety Monitoring Board  (DSMB) to compare their anti-viral candidate drug, CMX157 against tenofovir, a standard treatment for chronic hepatitis B (HBV).

ContraVir is a biopharmaceutical company that focuses on the development and marketing of antiviral therapies.  The company reported that they are starting to screen patients with chronic hepatitis B.  Those patients who meet the screening criteria will be enrolled in a Phase 2 head-to-head study.   They will be subjected for s clinical trial comparing ContraVir’s CMX157 to tenofovir DF or with a trademark name of Virea, marketed by Gilead Sciences.

The clinical trial will compare the different dosages of CMX157 starting from 5 mg daily against the standard dose of Viread which is 300 mg daily.  The company is expecting to complete the experimental trial in the fourth quarter of 2016.

The DSMB is an independent reviewing body that conducted the private review of the pharmacokinetic, tolerability and safety profile of CMX157. They based their recommendations from the Phase 1b safety study.  ContraVir performed a three completed dosing of CMX157 to healthy volunteers.

DSMB recommends the initiation of Phase 2a study and they also suggest the continuation of Phase 1b.  Today, the Phase1b is now in its midpoint where the researchers are determining the effects of the final two dosing groups which are the 50 mg and 100 mg, respectively.

James Saperstein, CEO of ContraVir noted that the Phase 2 Study will commenced the first ever evaluation of a targeted antiviral therapy which is compared to a standard drug in Hepatitis B. He said that the initiation of Phase 2 study is because of the encouraging result of the Phase 1b study. The clinical trial showed a good pharmacokinetic profile of CMX157 as it was still detected even at a 5mg once a day dosing.  The company noted that the 5mg was the lowest dose tested.

ContraVir pointed out that considering that they performed an animal data, the laboratory results and liver targeting showed superior potency of CMX157 against the Hepatitis B Virus in vitro.  The preliminary results proved the promising potential of CMX157 to be given at a lower dose than Viread and even in Gilead’s TAF or tenofovir alafenamide. In the clinical trial, the first dose of the experimental drug will be given to HBV patients.

The company has high hopes that they will be able to get positive results in the different dosing groups.

In the Phase 2a trial, 60 patients with chronic HBV infection will be enrolled in the program.  The study will consists of a sequential dose escalation starting with 10 patients for every cohort.  Each of the cohorts will receive a once-daily dose of either 5 mg, 10 mg, 25 mg, 50 mg or 100 mg of CMX157.  Two patients per cohort will receive the standard dose of Viread which is 300 mg.

Similar with the Phase 1b study, the initiation of a higher dose for each cohort will follow a review of data from the previous cohort.  Another review will be conducted by DSMB for 25 mg and 50 mg in CMX157 cohorts.   The final result is expected to be out in the fourth quarter of 2016.


ContraVir is working on an antiviral therapy that will be given in a lower dose as compared with the high dose therapy of the standard drug.  A lower dose means there is a lesser side-effect which is more beneficial for the patient.  If ContraVir is able to prove that the lower dose of CMX157 is better than the standard therapy, then this drug will be a promising treatment option.

Patients will be given an alternative option which has a more potent effect than the standard drug.

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