Australian drug development company Biotron has released results from its phase IIa trial of its lead drug candidate, BIT225 in Hepatitis C virus (HCV) infected patients.

Preliminary analysis of trial data confirms that BIT225, an orally administered, small molecule drug, has good antiviral activity against HCV. Patients receiving BIT225 in combination with interferon and ribavirin (the current standard of care for treating HCV) had greater reductions in HCV levels than patients receiving standard of care treatment alone.

Patients receiving the 400 mg dose of BIT225 showed the greatest levels of virus reduction, with an improvement of ~1 log (a measure of the amount of reduction of the virus in the blood of patients) over standard of care treatment at the completion of the dosing phase with BIT225. This is a significant improvement over and above the standard of care treatment in this patient group.

Twenty four patients who had passed a stringent screening process were randomly assigned to receive either 400 mg or 200 mg BIT225, or placebo, for the first 28 days of their standard treatment with interferon and ribavirin. The trial was undertaken at the Siriraj Hospital, Bangkok, Thailand. All patients were infected with genotype 1 HCV, which is the most common type of HCV and the most resistant to current treatment.

Since the completion of the clinical phase of dosing with BIT225 in, samples have been analyzed and the resultant data has been subject to preliminary review by the independent Data Safety Monitoring Committee.

BIT225's antiviral activity in this human trial supports the previously reported highly synergistic activity with interferon and ribavirin that was seen in cell culture models of HCV infection.

BIT225 is the first in a new class of direct-acting antiviral drugs for HCV. It specifically targets the p7 protein, a viral protein essential to virus production and replication.