Achillion Pharmaceuticals, Inc., based in New Haven, CT, has announced interim results from an ongoing Phase 2 study evaluating its investigational therapy ACH-3102, which is being developed to treat chronic hepatitis C virus (HCV) infection. As a second generation NS5A inhibitor, the drug has demonstrated effectiveness against all types of HCV in preclinical studies. A small molecule compound, NS5A works by disrupting nonstructural proteins HCV needs to replicate.

In the Phase 2 trial, ACH-3102 is being given in combination with sofosbuvir, without ribavirin (or interferon), for 8 weeks of treatment in patients with treatment-naïve genotype 1 HCV. Of the 12 patients treated, 100% achieved a sustained virological response (SVR) for four weeks after completing therapy. SVR signifies that a patient has “cleared” the virus when the viral load is reduced to undetectable levels in the bloodstream.

Ultimate success is measured by a patient’s ability to maintain SVR for at least six months after treatment ends. Though not technically a cure--HCV is often not entirely eradicated from the liver­­--SVR is still the goal for clinicians.  Lowering the viral load to undetectable levels decreases HCV’s harmful effects.

“ACH-3102 continues to demonstrate good safety and tolerability through three Phase 2 studies. We believe these studies also confirm a differentiated efficacy profile for an NS5A inhibitor,” said David Apelian, MD, PhD, Executive Vice President and Chief Medical Officer at Achillion.

According to the Achillion press release, 12 additional patients will begin treatment with six weeks of once daily ACH-3102 and sofosbuvir.

Source: Achillion press release dated August 15, 2014