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ContraVir claims CMX157 better than Gilead's TAF in hepatitis B; shares up 20%
http://seekingalpha.com/news/3170065-contravir-claims-cmx157-better-gileads-taf-hepatitis-b-shares-20-percent
Mar 29 2016, 13:02 ET | By: Douglas W. House, SA News Editor
Thinly traded nano cap ContraVir Pharmaceuticals (CTRV +20.1%) is up on a whopping 61x surge in volume in response to its announcement of results from a third-party laboratory (in vitro) study that showed greater antiviral activity in a hepatitis B virus (HBV) cell culture for product candidate CMX157 compared to Gilead Sciences' (GILD -0.9%) tenofovir alafenamide fumarate (TAF).
The study evaluated the anti-hepatitis B activities of CMX157 and other tenofovir prodrugs, including Gilead's Viread (tenofovir disoproxil fumarate), in order to profile CMX157. The ability of each to shut down HBV replication was determined by a parameter called effective concentration (EC), which measures the degree to which viral replication is inhibited for a given concentration of drug. EC50, for example, is the concentration of drug that reduces viral replication by 50%. EC50 values for CMX157 and TAF were 9.3 (range: 5.7 - 12.9) and 32.4 (range: 15.3 - 49.5), respectively. A lower value implies that the drug is more potent, although not necessarily more efficacious. EC90 (HBV viral replication inhibited 90%) values were 186 (range: 133 - 239) and 474 (range: 213 - 735), respectively. No values for Viread are provided.
ContraVir recently initiated a Phase 1/2a study assessing CMX157. The 2a portion, expected to commence in Q2, will compare it against Viread.
Tenofovir is a compound called a lipid acyclic nucleoside phosphonate. It is an effective antiviral agent but is limited by low oral bioavailability, renal toxicity and poor cell penetration. According to the company, CMX157's novel formulation enables it to deliver high intracellular concentrations of tenofovir thereby making it more effective at permanently suppressing HBV replication than existing drugs.
Gilead is currently transitioning its TDF (tenofovir disoproxil fumarate) products to TAF because its has equivalent efficacy at one tenth the dose and is easier on the bones and kidneys. The FDA cleared TAF for HIV-1 on March 1. Its marketing applications for hep B are currently under review in the U.S. and Europe.
Previously: ContraVir Pharma adds to up move, shares rise 22% (March 22)
Mar 29 2016, 13:02 ET | By: Douglas W. House, SA News Editor
Thinly traded nano cap ContraVir Pharmaceuticals (CTRV +20.1%) is up on a whopping 61x surge in volume in response to its announcement of results from a third-party laboratory (in vitro) study that showed greater antiviral activity in a hepatitis B virus (HBV) cell culture for product candidate CMX157 compared to Gilead Sciences' (GILD -0.9%) tenofovir alafenamide fumarate (TAF).
The study evaluated the anti-hepatitis B activities of CMX157 and other tenofovir prodrugs, including Gilead's Viread (tenofovir disoproxil fumarate), in order to profile CMX157. The ability of each to shut down HBV replication was determined by a parameter called effective concentration (EC), which measures the degree to which viral replication is inhibited for a given concentration of drug. EC50, for example, is the concentration of drug that reduces viral replication by 50%. EC50 values for CMX157 and TAF were 9.3 (range: 5.7 - 12.9) and 32.4 (range: 15.3 - 49.5), respectively. A lower value implies that the drug is more potent, although not necessarily more efficacious. EC90 (HBV viral replication inhibited 90%) values were 186 (range: 133 - 239) and 474 (range: 213 - 735), respectively. No values for Viread are provided.
ContraVir recently initiated a Phase 1/2a study assessing CMX157. The 2a portion, expected to commence in Q2, will compare it against Viread.
Tenofovir is a compound called a lipid acyclic nucleoside phosphonate. It is an effective antiviral agent but is limited by low oral bioavailability, renal toxicity and poor cell penetration. According to the company, CMX157's novel formulation enables it to deliver high intracellular concentrations of tenofovir thereby making it more effective at permanently suppressing HBV replication than existing drugs.
Gilead is currently transitioning its TDF (tenofovir disoproxil fumarate) products to TAF because its has equivalent efficacy at one tenth the dose and is easier on the bones and kidneys. The FDA cleared TAF for HIV-1 on March 1. Its marketing applications for hep B are currently under review in the U.S. and Europe.
Previously: ContraVir Pharma adds to up move, shares rise 22% (March 22)
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