For years, interferon alpha, and more recently consensus interferon from Amgen Inc., have been about the only treatments for hepatitis C. None are terribly effective and all have side effects, making the area an attractive one for new players.

Among new developments reported last week were clinical progress by Isis Pharmaceuticals Inc. and ViroPharma Inc., as well as discovery of a candidate vaccine by Epimmune Inc. Although developers of these technologies say they have intellectual property covering them, in the background looms Chiron Corp.'s significant HCV patent estate.