Promising interim results of a small study of Achillion Pharmaceuticals’ ACH-3102 and Gilead Sciences’ Sovaldi (sofosbuvir) indicated six weeks of treatment with the pairing may yield a perfect hepatitis C virus (HCV) cure rate among treatment naive people with genotype 1 of the virus, Reuters reports. Achillion announced the interim findings of the Phase II, open-label, randomized study of 12 participants taking the NS5A inhibitor ACH-3102 and the nucleotide analog polymerase inhibitor Sovaldi. Achillion also announced hopeful interim findings of a proof-of-concept Phase I trial of the nucleotide inhibitor ACH-3422, which the company intends to pair with ACH-3102 and possibly the protease inhibitor sovaprevir in future trials.

Four weeks after completing six weeks of therapy with ACH-3102 and Sovaldi, 100 percent of the participants achieved a sustained virologic response (SVR4). This is a good indication that all 12 of them will make it another eight weeks to achieve an SVR12, which is considered a cure. Achillion will announce final results from the trial during the first half of 2015.

The drug pairing proved well tolerated. There were no serious adverse events, no one stopped therapy because of adverse events, and there were no clinically significant laboratory or electrocardiogram abnormalities.

Meanwhile, the proof-of-concept trial of ACH-3422 showed that the drug apparently has good antiviral potency. When taking 700 milligram dose, three out of six participants achieved an undetectable viral load after 14 days of treatment. There was a high average reduction in viral load among the group as a whole.

“The safety profile, potent antiviral activity, and high barrier to resistance observed with ACH-3422 in this Phase I trial exhibit the important characteristics a nucleotide inhibitor provides in HCV treatment regimens,” David Apelian, MD, PhD, executive vice president of clinical development and chief medical officer at Achillion, said in the same press release. “The data, combined with the Phase II proxy study results, lead us to believe that the doublet regimen of ACH-3102 and ACH-3422 can be a highly competitive regimen to cure HCV. Furthermore, the ability to explore a triplet regimen with sovaprevir, our protease inhibitor, may allow for shorter treatment durations especially in harder-to-treat patient populations.”

To read the Reuters story, click here.