Pharmasset has received a fast-track designation from the US Food and Drug Administration (FDA) for PSI-7977, a potential treatment for chronic hepatitis C.

PSI-7977 is an oral uridine nucleotide analog polymerase inhibitor of the hepatitis C virus.

Pharmasset recently completed dosing in a 28-day Phase IIa trial designed to evaluate PSI-7977 in combination with Pegasys (pegylated interferon) and Copegus (ribavirin), in treatment-naïve patients who were chronically infected with hepatitis C virus genotype 1.

The drug maker plans to initiate a 12-week Phase IIb study of PSI-7977 in the fourth quarter of 2010.

Dr Michael Rogers, chief development officer at Pharmasset, said that no nucleotide inhibitors have been approved for the treatment of chronic HCV infection.

“We continue to work closely with the FDA on the development and regulatory review of PSI-7977,” Rogers added.

FDA fast-track designation is given to expedite the approval process of drugs that could treat serious illnesses and have potential to address an unmet clinical need.