The drug is the latest antiviral treatment to treat the blood-borne infectious disease of the liver and a leading cause of cirrhosis, liver cancer and the need for liver transplants.
According to the Centers for Disease Control and Prevention (CDC), an estimated 4.1m Americans (1.6 per cent) have been infected with hepatitis C; 3.2m are chronically infected.
The number of new infections per year has declined from an average of 240,000 in the 1980s to about 26,000 in 2004. CDC estimates the number of hepatitis C-related deaths could increase to 38,000 annually by the year 2010, surpassing annual HIV/AIDS deaths.
Roche's Phase I results with the hepatitis C polymerase inhibitor R1626 were achieved in chronic hepatitis C patients infected with the difficult-to-treat genotype 1 virus.
In this Phase I study, 47 patients with genotype 1 hepatitis C were randomised to receive either oral treatment with R1626 twice daily or placebo for 14 days.
The final results included patients who received the higher doses of R1626 at 3,000 mg or 4,500 mg twice a day.
The study found that R1626 showed good tolerability following dosing for 14 days up to 3,000 mg twice daily. No patient was prematurely withdrawn from the study.
However, increasing numbers of adverse events were noted at higher dose levels. Reversible mild to moderate haematological changes were observed with increasing doses.
As a result of these promising results, Roche has already commenced a Phase II trial to evaluate how well R1626 works in combination with Pegasys (peginterferon alfa-2a) and Copegus (ribavirin USP).
"These Phase I study results suggest that R1626 holds significant promise for the treatment of hepatitis C," said Dr. Stuart Roberts, director of Gastroenterology at Alfred Hospital in Melbourne, Australia and lead investigator of the study.
"Adding R1626 to the current therapies could potentially improve treatment success rates in hepatitis C."
Pegasys, in combination with Copegus, are indicated for the treatment of adults with chronic hepatitis C who have compensated liver disease and have not previously been treated with interferon alpha.
Pegasys in combination with Copegus is the first and only FDA-approved regimen for the treatment of chronic hepatitis C in patients coinfected with hepatitis C and HIV.
"Roche is fully committed to developing better treatment options for hepatitis C so that as many patients as possible can have the best chance for successful treatment," said Nick Cammack, head of Viral Diseases Research, Roche.
"The development of R1626, ongoing research with PEGASYS and partnerships with Intermune, Pharmasset, and Maxygen underscore Roche's long-term commitment to finding effective therapies to benefit patients with chronic hepatitis C," he added.