Toxicity trips Vertex's timing

Long-term animal toxicity studies are routinely continued when a compound is already in the clinic. One of the downsides is that new findings can set back clinical progress significantly, which was illustrated last week when Vertex Pharmaceuticals Inc. decided to halt development of its VX-745 p38 MAP kinase inhibitor.

Although the company has two chemically distinct second generation compounds moving into development, its program will be set back by about a year. ...