Vertex: A small bump in the road

Although VX-497 missed its target for viral load reduction in a Phase II trial in hepatitis C virus infection, Vertex Pharmaceuticals Inc. is looking forward to a longer Phase III study, with a more closely defined patient population. The company thus believes that it can offset the shortcomings of the Phase II study's short duration and patient population with highly variable HCV RNA levels upon entry, and give VX-497 a better chance of showing significant viral load reduction.

In the four-week, 54-patient study, subjects received either interferon-alpha alone or in combination with VX-497, an oral small molecule inhibitor of inosine monophosphatase dehydrogenase (IMPDH). Although the end point of lowered HCV RNA compared to interferon monotherapy was not met, patients receiving the combination did have an accelerated decrease in HCV RNA from baseline versus interferon alone(see BioCentury, Feb. 26). ...