The drug is now in the final testing stages. If all goes well, it could be on the market in 2011.
"People believe this is a really significant improvement in how we'll be able to care for patients with hepatitis C," said Dr. John McHutchison, a Duke doctor who studies liver diseases and the lead investigator of the study, which is published in Thursday's New England Journal of Medicine.
The disease, spread by a virus in blood, is the leading cause of liver transplants in the United States.
Many people who have hepatitis C have no symptoms for years and even decades. They are diagnosed only when they begin suffering liver disease or the virus is detected in a blood test.
Currently, treatment cures about 41 percent of patients. And it is expensive, costing upwards of $20,000 for a full regimen.
It is also notoriously challenging. Patients must get weekly shots for nearly a year, plus take daily pills. Side effects are numerous and often debilitating - anxiety, depression, fatigue, headache, fever, poor appetite, dry mouth and sores, hair loss, nausea and chest pains.
"It's really devastating," said Ron Smith, 55, of Wilmington, N.C., who was diagnosed with the disease in 2001 and underwent treatment that he says made him feel like he had been hit with the flu for a year.
The new drug, called telaprevir, works by disabling the virus's ability to reproduce. It's designed to be used in conjunction with the current therapies, so patients would still face the potential side effects. But because it cuts the length of time on therapy to just six months, many more patients might stick with the treatments.
"That would help so many people," Smith said, noting that he has counseled numerous people who have had to drop out of treatment because they couldn't tolerate it.
"Obviously a lot of this stuff will impact overall quality of life and relationships," said Tim Virgilio, a social worker at the Durham VA Medical Center who coordinates the hospital's hepatitis C support group.
Virgilio and others who work with hepatitis C patients said they were eager for a new drug and that the telaprevir therapy has been widely anticipated. Another drug that operates on the same principle is in the pipeline, but a report last fall indicated many people found it too harsh.
McHutchison at Duke said telaprevir also has side effects; it appears to worsen rashes and anemia associated with traditional therapies. Still, the drug is being welcomed as the brightest treatment prospect in years for hepatitis C.
An editorial in the New England Journal of Medicine calls telaprevir a "material advance in the therapy of hepatitis C, beginning a new era of treatment."
The last big breakthrough for the liver disease was in 2001, when the Food and Drug Administration approved a time-release formula of the antiviral drug interferon. That allowed patients to get weekly injections of the drug instead of three times a week.
Still, much remains to be determined. The telaprevir drug trial has enrolled 1,000 patients for the final Phase 3 study before FDA approval. And it's unknown how much it will add to the cost of already expensive therapies.
Susan Thompson, adult viral hepatitis prevention coordinator with the state Division of Public Health, said she hopes that by shortening the duration of treatment, the new drug could actually reduce costs.
Even if it doesn't, though, she said patients would welcome the prospect of cutting their treatment time in half.
"Oh yeah," she said. "This can be a very complicated condition to treat."
THE VARIETIES OF THE DISEASE
Hepatitis A: Spreads primarily through food or water contaminated by stool of an infected person. Rarely causes lasting damage. There is a vaccine.
Hepatitis B: Passed through contact with an infected person's blood, semen or other body fluid. Causes flulike symptoms that usually improve after a few months, but can become long term. Chronic HBV can lead to scarring of the liver, liver failure or liver cancer. There is a vaccine.
Hepatitis C: Usually spreads through contact with blood. It can also spread through sex and from mother to baby during childbirth. Most people who are infected with hepatitis C have no symptoms for years. Infection can lead to liver scarring, liver cancer and the need for transplant. No vaccine.