Biotech, Hepatitis C, clinical trials

Vertex’s Hepatitis C Drug Passes Test, Moving to Another Phase III

Luke Timmerman 6/9/08

Vertex Pharmaceuticals is on a roll. The company’s experimental drug, telaprevir, helped wipe out the hepatitis C virus for more than half of volunteers in a clinical trial who had previously failed to respond to standard therapy.

Shares of the Cambridge, MA-based company (NASDAQ: VRTX) shot up as much as 7 percent in early trading, then settled down to a 3.5 percent gain, to $33.38 at 12:38 p.m. Eastern time. The stock has climbed 43 percent since the first of the year.

Hepatitis C, a virus that damages the liver, affects an estimated 3.4 million people in the U.S., meaning there is potentially big money to be made in treating it. Earlier studies of telaprevir showed it could help eliminate the virus for nearly two-thirds of patients who were new to treatment, about twice as effective as standard therapy, pegylated interferon and ribavirin. (The measure of success for these drugs, called “sustained viral response” or “clinical cure,” is when the virus disappears and doesn’t come back for at least 24 weeks after patients quit taking the medicine.) The latest study, called Prove 3, shows that Vertex’s drug may knock out the virus that well for patients who never responded to a previous round of standard therapy, or did momentarily and later relapsed.

Based on the finding, Vertex plans to start a final-stage clinical trial by the end of September for telaprevir in patients who failed earlier therapy. That study will run in parallel with another big Phase III trial, called Advance, which began recruiting more than 1,000 patients new to treatment in March.

The Prove 3 results showed that 52 percent of 115 patients who were randomly assigned to a 24-week course of treatment that includes telaprevir had their virus wiped out for at least 12 weeks after they quit taking the drug. Patients in a control group got the standard course of treatment, which is required to run 48 weeks, almost a year. At the same yardstick for measuring cure rates—36 weeks into that course—about 30 percent of patients in the control group had no evidence of the virus, Vertex said. Telaprevir’s side effects were similar to those of standard treatment, Vertex said.

Patients also responded well to telaprevir in another study, called ‘107, released in April at the European Association for the Study of the Liver in Milan. Doctors are continuing to observe those patients to see how long-lasting the effect will really prove to be.

Luke Timmerman is the National Biotechnology Editor for Xconomy. You can e-mail him at ltimmerman@xconomy.com, call 206-624-2374, or follow him on Twitter at http://twitter.com/ldtimmerman.