Schering-Plough published promising new data for its experimental hepatitis C drug boceprevir, which pushed down the share value of rival Vertex Pharmaceuticals. After 48 weeks of therapy, researchers said, three out of every four patients receiving boceprevir in combination with standard therapy had undetectable levels of the virus. That compares to 38 percent with undetectable viral levels in the standard therapy arm.
None of that Phase II data is likely to sway analysts who pegged Vertex's closely watched telaprevir as the likely winner in the race to an FDA approval. But hepatitis C is a very competitive disease field, and a rival therapy could quickly eat into its revenue. Vertex shares lost 11 percent on the news from Schering-Plough.