Gilead Sciences’ bet on the $11 billion acquisition of Pharmasset starts to earn some reward as the newly-acquired Hepatitis C drug candidate showed impressive results in clinical study, sending the company share price up by 11 percent to $54.70 at the close of trading in New York.

The Foster City, CA-based Gilead said that its experimental drug GS-7977, originally known as PSI-7977 before the acquisition, when combined with ribavirin, cured a group of genotype 1 hepatitis C patients after four weeks of treatment. The clinical study involved hepatitis C patients who either failed to respond to previous therapies or had not been treated before. The genotype 1 is the most common form of HCV in the United States. It affects 70 to 90 percent of the people in this country who have hepatitis C.

Norbert Bischofberger, chief scientific officer at Gilead said patients with genotype 1 hepatitis C had no detectable signs of the virus after treated with GS-7977 combination therapy for a course of close to a month. Previous study showed the drug candidate could also cure patients with genotype 2 and 3 HCV.

Gilead gained rights to GS-7977 through the $11 billion Pharmasset acquisition deal, which enable the company to be in an advanced position to compete with a few pharma companies seeking to develop an all-oral regimen for hepatitis C. The 100 percent cure rate data suggested that GS-7977 may be one of the most promising therapies for hepatitis C.

Last year, GS-7977, an oral uridine nucleotide analog polymerase inhibitor of HCV, received fast track designation from the U.S. FDA for the treatment of HCV infection.

The World Health Organization estimated that 3-4 million people are infected with HCV each year. Some 130-170 million people are chronically infected with HCV and at risk of developing liver cirrhosis and/or liver cancer,  and more than 350,000 people die yearly from hepatitis C-related diseases.

Pharmaceutical companies including Merck, Vertex, Abbott, Roche, Johnson&Johnson, and Bristol-Myers Squibb, have been developing novel orally active therapies hepatitis C to replace older injectable drugs. Following Gilead’s acquisition of Pharmasset, BMS last month stroked a deal to buy Inhibitex with $2.5 billion for its experimental hepatitis C therapies.

Related Articles:

1. Gilead aquires Pharmasset for $11 Billion for Hepatitis C Drugs
2. PSI-7977 Receives Fast Track Designation from the FDA for the Treatment of Chronic Hepatitis C Infection
3. Merck and Roche initiate trials of hepatitis C combo therapy
4. Abbott’s ABT-450/r shows impressive results in mid-stage hepatitis C trial
5. BMS boosts its hepatitis C pipeline with $2.5 billion Inhibitex deal