The government is launching an eight-year study to test anti-viral drug treatments for the 4 million Americans infected with chronic hepatitis C.
Hepatitis C can lead to cirrhosis and liver cancer in some patients and results in about 1,000 liver transplants annually in the United States.
The $28 million clinical trial will be funded by the National Institute of Diabetes and Digestive and Kidney Diseases, a division of the National Institutes of Health.
Researchers will try to determine if long-term treatment with drugs can slow or prevent the progression of liver disease in hepatitis C patients.
The trials will begin next year at nine centers around the country, the Institute said. Researchers will decide this summer which drugs will be used and the number of volunteers to be recruited.
Blood transfusions and sharing unsterilized needles and syringes have been the main causes of the spread of hepatitis C in the United States. The disease ranks with alcohol abuse as the most common causes of liver disease.
"As the largest and longest study of hepatitis C, this trial should provide answers to difficult questions concerning management of hepatitis C," Dr. Jay H. Hoofnagle, director of the division of digestive diseases and nutrition, said in a statement.
The nine trial centers are the University of California, Irvine; University of Southern California, Los Angeles; University of Colorado Health Sciences Center, Denver; Massachusetts General Hospital, Boston; University of Massachusetts Medical School, Worcester; St. Louis University, St. Louis, Mo.; University of Michigan, Ann Arbor; University of Texas Southwestern Medical Center, Dallas and Medical College of Virginia, Richmond.