S-P's boceprevir shows 74% SVR in HCV

Schering-Plough reported better-than-expected top-line results from an interim analysis of a Phase II study of boceprevir, its investigational oral hepatitis C protease inhibitor, leading shares in the US drug major to rise almost 3% to $20 on August 4.

The analysis showed a 74% rate of sustained virologic response for boceprevir-based combination therapy in the study of 595 treatment-naive patients with chronic hepatitis C virus genotype-1. The strong efficacy findings undermined confidence in Vertex' rival product telaprevir, which is closer to the market. Shares in the US firm fell nearly 11% on the day the results were reported, August 4. Patients in the study who received 48 weeks of boceprevir in combination with Pegintron (peginterferon alfa-2b) and Rebetol (ribavirin) from the beginning of treatment achieved 66% SVR 12. In the two 28-week boceprevir arms of the study, SVR 24 was 56% and 55% for patients in the lead-in and no lead-in arms, respectively.