By Peter Loftus Of DOW JONES NEWSWIRES A regimen combining experimental drugs from Gilead Sciences Inc. (GILD) and Bristol-Myers Squibb Co. (BMY) suppressed the hepatitis C virus in most patients four weeks after completing treatment, according to a new study. The companies are awaiting additional data on whether the liver-disease-causing virus remains suppressed over a longer follow-up period. They are also studying whether halving the course of treatment to 12 weeks will achieve the same results. But the results released Thursday suggest the Gilead/Bristol-Myers regimen has potential as an all-oral regimen for hepatitis C that eliminates an injectable drug used in standard treatment, interferon, which can be difficult for patients to tolerate. It may also support the elimination of another drug used in current treatment, ribavirin. Several drug makers are racing to come out with the best interferon-free, oral regimen, hoping to tap into a multi-billion-dollar market for hepatitis C therapies. The Gilead-Bristol combination study was among several new studies of hepatitis C therapies released Thursday at the annual scientific meeting of the European Association for the Study of the Liver, or EASL, in Barcelona. The study tested Gilead's GS-7977, which it acquired in its $11 billion purchase of Pharmasset earlier this year, and Bristol-Myers' daclatasvir. Each works by a different mechanism to attack hepatitis C, which can cause inflammation of the liver. The Gilead compound, GS-7977, is a so-called nucleotide inhibitor, or "nuke," which Gilead believes could be the cornerstone of the first all-oral regimen for hepatitis C. Bristol's daclatasvir is known as an NS5A inhibitor replication complex inhibitor. The companies studied three regimens in 88 hepatitis C patients. In one arm, patients were assigned to take GS-7977 for seven days, then a combination of GS-7977 and daclatasvir for 23 weeks. The second group was assigned to take both drugs for 24 weeks, and the third group took both drugs plus an older drug, ribavirin, for 24 weeks. Each of three regimens had patients divided into two groups: those with genotype 1 hepatitis C--the most common form of the disease in the U.S. and one that is difficult to treat--and a group combining genotypes 2 and 3. At four weeks following completion of treatment, 100% of the genotype 1 patients across all three treatment regimens had achieved a sustained virologic response, or SVR 4, according to Bristol-Myers. A sustained virologic response that holds up over time is considered by many doctors to be a cure. Among the genotype 2/3 patients, 91% achieved SVR 4. The breakdown was 100% in the group that received GS-7977 and daclatasvir for 24 weeks; 88% in the group receiving the seven-day lead-in with GS-7977; and 86% for the group that received ribavirin in addition to the experimental drugs. Adverse events included fatigue, headache and nausea, and were generally mild to moderate. The results "clearly put this combination into a leading position," said Douglas J. Manion, a senior vice president in Bristol's research-and-development division. However, Manion said Gilead hasn't agreed to move the combination regimen into a late-stage, or Phase 3, study that could generate data to support a filing for regulatory approval. A Gilead spokeswoman declined comment on its plans for the combination. Bristol-Myers recently obtained another so-called "nuke" drug with its $2.5 billion acquisition of Inhibitex. New data from a separate study of Gilead's GS-7977 plus ribavirin are also scheduled to be released Thursday at the EASL meeting. -By Peter Loftus, Dow Jones Newswires; +1-215-982-5581; peter.loftus@dowjones.com
