WEDNESDAY, April 7, 2010 (HealthDay News) -- Adding the antiviral drug telaprevir to a second-round treatment for hepatitis cures about half the people who were not helped in the first round, new research shows.
"This is the first large study in patients who had not responded to standard treatment," said Dr. John G. McHutchison, associate director of the Duke Clinical Research Institute and lead author of a report in the April 8 issue of the New England Journal of Medicine.
The study is one of the last steps in a series of trials designed to get approval for the use of the drug in clinical practice. Approval of the drug will bring encouragement to people whose hepatitis C infection had not been cured by the existing treatments, McHutchison said.
"There has been no alternative for people who have been treated and have not responded," he added. "So it holds great promise for them, that potentially something will be available in the future that can cure half of them."
About 4 million Americans are infected with hepatitis C, a virus that is the leading cause of cirrhosis and liver cancer and the most common reason for liver transplantation. It is usually transmitted by infected blood, most often by using a contaminated needle.
Standard treatment for hepatitis C is a 48-week course of two drugs, peginterferon alpha and ribavirin, which cures about 40 percent to 50 percent of patients but is accompanied by side effects, such as a severe rash, that makes many discontinue the treatment. Previous studies have shown a substantial improvement in cure rates when telaprevir is added to the standard therapy.
Until now, the only recourse for those who were not helped by the first round of treatment was a second round of the same therapy. The newly reported trial, sponsored by Vertex Pharmaceuticals, the maker of telaprevir, included 453 people who had not responded to a first round of treatment. All had the most common, and most difficult to treat, form of the virus, genotype 1.
Just over half, 52 percent, of those who had telaprevir added to the two-drug regimen in the second round were virus-free after six months, compared to 14 percent of those who had a second round of the two-drug treatment.
But the therapy was not problem-free, McHutchison noted. "There were also more side effects, rashes and anemia," he said. "Also, the rate of discontinuation was higher as well."
Still, the high cure rate speaks for itself, McHutchison added. Data from the various trials probably will be submitted to the U.S. Food and Drug Administration later this year, he said.
Telaprevir is a protease inhibitor, which works by blocking reproduction of the hepatitis C virus. It is not the only protease inhibitor being tested against hepatitis C, McHutchison said. Another such drug, boceprevir, appears to be running close to telaprevir in the race for regulatory approval. It is being developed by Merck, which acquired it when it bought Schering-Plough.
If and when they are approved, both protease inhibitors probably will be used for first-line treatment of hepatitis C, McHutchison said.
"Having more options for the patient is what it is all about," he explained.
A number of other protease inhibitors now are in various stages of testing, added Dr. Ira Jacobson, a professor of medicine at Weill Cornell Medical College in New York City and a member of the research team that did the telaprevir study. Jacobson has also been involved in development of boceprevir.
A new era in treatment of hepatitis C will begin when a first protease inhibitor is approved, Jacobson said. "The hope in the medical community is that the regulatory agencies will see fit to approve it for all populations," he added.
To learn about hepatitis C, visit the U.S. National Library of Medicine.