CAMBRIDGE, Mass — Vertex Pharmaceuticals Inc. said Wednesday a safety analysis of its developing hepatitis C drug VX-950 showed 9 percent of the patients involved dropped out of the program because of adverse events including gastrointestinal disorders and rash.
The news sent shares of Vertex fell 62 cents to $38.78 in morning trading on the Nasdaq, following a drop in premarket trading.
The midstage study involved 250 patients, with the current interim data involving 74 patients for whom data was available at 12 weeks. Patients were given either the drug, called telaprevir, or placebo in combination with ribavirin. The safety study results showed that 9 percent discontinued treatment because of adverse events, with rash being the most common, compared with 3 percent of the patients taking placebo.
The company said serious adverse events accounted for 3 percent compared with 1 percent taking placebo.
"Evaluation of telaprevir's safety and antiviral activity in multiple large clinical trials is Vertex's top clinical priority in the year ahead," said Joshua Boger, president and chief executive, in a statement.
He said the interim analysis supports the need to conduct a larger clinical trial to further test the drug candidate's safety and effectiveness.
The data did show that of the 74 patients for which data was available, 65 _ or 88 percent _ had undetectable hepatitis levels compared with 17 of 33 _ or 52 percent _ in the placebo portion.
Dosing in the study is expected finish this month and the company said it will present more results at a medical forum in 2007.
Vertex earned a $15 million milestone payment from Janssen Pharmaceutica NV based on the results so far.
source - AP