Phase II Clinical Trial Shows Vertex’s Experimental Protease Inhibitor Lowers Hepatitis C Viral Loads to Undetectable Levels

Cambridge, Mass.-based pharmaceutical company Vertex Pharmaceuticals on Tuesday released results of a Phase II clinical trial that showed its experimental drug VX-950 lowered hepatitis C viral loads to undetectable levels, the AP/Houston Chronicle reports (AP/Houston Chronicle, 2/7). The 28-day trial enrolled 12 people living with the virus who had never taken medication to treat hepatitis C. Patients received VX-950 in combination with the drugs interferon and ribavirin (Vertex release, 2/7). According to a Vertex release, all 12 patients had undetectable viral loads after 28 days of treatment, and there were no treatment discontinuations or "serious adverse events" reported during the trial (Vertex release, 2/7). The injection drug interferon -- sold under the brand names Pegasys and Peg-Intron by Roche and Schering-Plough, respectively -- and ribavirin, originally developed by Valeant Pharmaceuticals, are the current common therapy used to treat the virus, the New York Times reports (Pollack, New York Times, 2/7). Current therapies require patients to inject themselves with an interferon treatment once each week for 24 to 48 weeks, depending on the strain of the virus. The treatments cause severe side effects and cure about 50% of the cases. According to the Times, Vertex is hoping VX-950 will reduce duration of treatment for hepatitis C patients to three months. However, despite "strong early results" from clinical trials, there is evidence that the virus might become resistant to the drug, the Times reports (New York Times, 2/7). The company plans to present full data from the trial at a conference later this year (Vertex release, 2/7). Schering-Plough, Boehringer Ingelheim, Bristol-Myers Squibb and InterMune also are developing experimental protease inhibitors, which have been successful in treating HIV/AIDS, to treat hepatitis C (New York Times, 2/7).