An expert panel on Thursday unanimously voted in support of a second new hepatitis C drug, Vertex Pharmaceuticals' telaprevir, which studies suggest can boost cure rates of the liver disease.
The advisory panel, which makes recommendations to the Food and Drug Administration, on Wednesday lent its 18-0 support to a similar drug, boceprevir, made by pharmaceutical giant Merck.
Both drugs are protease inhibitors and are to be added to the current two-drug treatment of pegylated interferon and ribavirin for genotype 1 chronic hepatitis C.
Doctors said the new class of drugs will greatly improve the cure rate for hepatitis C, a liver disease which affects about 180 million people worldwide. Currently only about half of patients are helped by drug therapy.
The results of phase III trials showed that patients who had never been treated for their hepatitis C before had a 79 percent cure rate when taking the three drug combination, compared to 46 percent on the two-drug regimen.
Among patients in the trial who undergone treatment before, the addition of the third drug lifted the cure rate to 78 percent, compared to 21 percent on the existing therapy.
Side effects of the 12-week course of medication mainly included rash and anemia.
The FDA does not have to follow the recommendations of its advisory panel but it often does. A final decision is expected by May 23.
There is currently no vaccine for the hepatitis C virus, and the Centers for Disease Control and Prevention estimates that more than 12,000 people die each year of liver disease and liver cancer associated with the illness.
Most people infected with hepatitis C live symptom-free for years, but once it is discovered it is often too late for it to respond to the current two-drug treatment.
In the past the disease could be spread through contact with infected blood products, and is still contracted by drug users sharing needles or straws during the use of cocaine, or by unprotected sex with a sufferer.