Reuters Health Information (2010-08-10): Hep C protease inhibitor telaprevir works in 24 weeks: study
Drug & Device Development
Hep C protease inhibitor telaprevir works in 24 weeks: study
Last Updated: 2010-08-10 12:37:29 -0400 (Reuters Health)
NEW YORK (Reuters) - A study of Vertex Pharmaceuticals Inc.'s high profile experimental hepatitis C drug telaprevir showed that the overwhelming majority of previously untreated patients who respond early can be cured in half the time of current therapy.
Ninety-two percent of rapid responders who received 24 weeks of therapy with telaprevir plus the standard treatment of pegylated interferon and ribavirin achieved a sustained virologic response (SVR).
The overall cure rate for all telaprevir patients was 72% in the study, a touch below the 75% seen in an earlier Phase III trial. But most patients in whom the virus is cleared early may be able to complete treatment in half the time of current, tough to tolerate, therapy, the data showed.
Telaprevir is widely expected to become a multibillion-dollar drug for Vertex because of its ability to cure a far higher percentage of patients than standard drugs and its potential to cut treatment duration.
In the earlier Phase III trial of previously untreated patients, interferon and ribavirin without telaprevir produced an SVR in only 44%.
The latest late-stage trial focused on patients who had undetectable viral load at both week 4 and 12 of treatment with the three-drug combination, to see if there was any advantage to extending therapy with standard drugs beyond 24 weeks to the full 48 weeks in those patients.
Sixty-five percent of the 540 trial participants fell into the rapid responder category. In all cases, telaprevir was part of the regimen for the first 12 weeks.
Among those rapid responders, there was an 88% SVR rate with the full 48 weeks - slightly less than with 24 weeks. But the relapse rate was 1.9% in the 48-week group vs 5.7% with the 24-week regimen, or 3 patients versus 9.
"Patients who had a rapid response to telaprevir-based regimens at weeks 4 and 12 had a high likelihood of achieving a cure with 24 weeks of total treatment, which may provide important information to motivate people to continue therapy," Dr. Kenneth Sherman, principal investigator of the trial, said in a statement.
The company next month is expected to release data from one more Phase III study, this time in much tougher-to-treat patients who failed to respond to prior therapy with standard drugs.
The three late-stage trials will form the basis for Vertex's application seeking approval of the drug that it plans to file with the U.S. Food and Drug Administration by the end of the year.
Telaprevir, from a new class of hepatitis C treatments, is expected to compete with a similar drug being developed by Merck & Co. called boceprevir. But boceprevir is linked with a high rate of anemia, and analysts have been virtually unanimous in their belief that telaprevir is the better of the two drugs. (See Reuters Health stories of Aug 4 and Aug 9, 2010.)
The safety and tolerability of telaprevir in the latest Vertex trial was similar to what was seen in the earlier late-stage study, the company said.
Adverse events, including rash and anemia, led to discontinuation by nearly 7% of patients.