Telaprevir, a drug approved by the U.S. Food and Drug Administration in May, and a similar medication boceprevir have nearly doubled the number of patients with sustained response, the study said.
Among patients treated with telaprevir, pegylated interferon and ribavirin in the new study, 72 percent were cured of their hepatitis C, the researchers said.
The study showed patients who are clear of the virus within the first four to 12 weeks of therapy effectively can cut their treatment time from 48 weeks to six months.
"This means that rather than a one-size-fits-all approach, we can individualize treatment for patients based on their specific response to the drugs," senior author Dr. Fred Poordad, chief of hepatology and liver transplantation at Cedars-Sinai in Los Angeles, said in a statement.
"Once you're cured by these antiviral drugs, you're cured of hepatitis C completely. That's a little known fact among the public -- and even among physicians who don't regularly treat liver disease."
The findings were published in the New England Journal of Medicine.