Oral drug regimen for hepatitis C shows promise in trial
Scientists with the National Institute of Allergy Infectious Diseases and the NIH Clinical Center led the Phase II trial of sofosbuvir, an experimental drug, and published the findings in the Wednesday issue of the Journal of the American Medical Association. The study involved 60 volunteers with genotype-1 HCV, which is usually less responsive to interferon-based HCV treatment. Fifty of the participants in the study were African-American.
"While African-Americans make up about 13 percent of the U.S. population, they represent more than 22 percent of people with chronic HCV infection and, compared to whites, have lower cure rates with traditional HCV therapy," Shyam Kottilil, the trial's principal investigator, said. "Several recently completed trials testing interferon-free regimens have yielded promising results, but most volunteers in those studies were white."
In the first part of the study, 10 people with mild or moderate liver fibrosis received oral ribavirin at a weight-based dosage along with sofosbuvir daily for six months. Of the nine volunteers who completed the course of therapy, the virus was undetectable 12 weeks after the end of therapy and remained undetectable 24 weeks after finishing therapy. Patients are considered cured when the virus is not detected 12 weeks after stopping therapy.
The second part of the study tested 50 volunteers, 13 of whom had serious liver damages. Half of the participants received weight-based ribavirin doses and 25 received a lower dose. Everyone received sofosbuvir. Seventeen of the weight-based arm had undetectable virus levels 24 weeks after the treatment. Twelve were considered cured in the low-dose ribavirin arm at 24 weeks after treatment.
"We saw an overall cure rate of about 70 percent using regimens that did not include interferon," Kottilil said. "This is an encouraging result, especially considering the proportion of volunteers who had characteristics - such as being male, having HCV genotype-1 infection, being African-American and having advanced liver damage - that are recognized as predictors of poor response to treatment."
More trials are underway to determine if regimens without ribavirin or interferon can help people with chronic HCV infection.
More than three million Americans have chronic HCV infection, a major cause of cirrhosis and liver cancer. HCV-related liver disease causes approximately 15,000 deaths annually.