Vertex shares fall on rival news

Shares of Vertex Pharmaceuticals Inc fell nearly 20 percent today amid growing concern that its experimental hepatitis C drug may face greater competition than expected.

Analysts at Leerink Swann & Co. downgraded the stock to "market perform" from "outperform," based on presentations being made at a conference in Boston indicating that competition to Vertex's drug telaprevir will become increasingly visible in the next few months and that "the competitive news could further affect the sentiment on the stock."

The plunge in Vertex's stock follows a decline of roughly 9 percent on Friday, after the company released data on the drug that were not as strong as some investors had expected, while other companies presented data that were unexpectedly promising. (Reuters)