A hepatitis C treatment being developed by Vertex Pharmaceuticals led to a 75 percent cure rate in a pivotal trial of previously untreated patients, the company said.
The results from the first late-stage Phase III study of the drug telaprevir came in at the high end of expectations for a cure rate of 70 to 75 percent, with slightly lower discontinuation rates due to side effects than previously seen.
Seventy-five percent of patients who received 12 weeks of telaprevir in combination with current standard treatment of pegylated interferon and ribavirin, followed by either 12 or 36 weeks of standard treatment, achieved a sustained virologic response, or SVR, which is tantamount to a cure.
That compared with a 44 percent SVR rate for patients who received the usual 48-week regimen of the standard drugs.
Telaprevir is in a race with a similar drug called boceprevir being developed by Merck.
Data from two more Phase III trials of telaprevir, including results in patients who failed with previous treatment, is expected in the third quarter. The first boceprevir late-stage data will be released later this year.
Through mid-stage studies, most analysts have tabbed the Vertex drug as superior.
In a third arm of the Phase III study, 69 percent of patients who received the telaprevir combination for just eight weeks followed by either 16 or 40 weeks of the standard drugs achieved SVR, Vertex said.
There has been great hope for this new class of antiviral drugs for the serious liver disease because of the potential for significantly higher cure rates and the possibility of cutting the duration that the standard drugs must be taken.
Though tough to tolerate, standard drugs — interferon and ribavirin — offer cure rates in the 40 to 50 percent range. They must be taken, though, for 48 weeks and often cause debilitating flu-like symptoms, causing many patients to discontinue their use.
Several drugmakers are working on next-generation drugs with the hope they could be combined with treatments like telaprevir and eliminate the need for interferon altogether.
"The results highlight that telaprevir-based combination regimens may increase viral eradication rates and shorten treatment time for many patients," Dr. Ira Jacobson from Weill Cornell Medical College and a researcher for the study, said in a statement.
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