Vertex Posts Initial HCV Data

Vertex Pharmaceuticals has released the first data from the initial cohorts of an open-label Phase IIa study of VX-135, Vertex’s nucleotide analogue hepatitis C virus (HCV) polymerase inhibitor, in combination with daclatasvir, Bristol-Myers Squibb‘s NS5A replication complex inhibitor. In an intent-to-treat analysis, the sustained viral response rate four weeks after the completion of treatment (SVR4) was 83% (10 of 12) in treatment-naïve genotype 1 patients who received 200 mg of VX-135 in combination with daclatasvir. In this arm, one patient discontinued treatment after the first dose due to a serious adverse event of vomiting/nausea. The 11 other patients in this arm completed 12 weeks of treatment, and 91% (10 of 11) achieved SVR4. In the study, the majority of adverse events were mild.

The initial two cohorts of the study evaluated 100 mg and 200 mg once-daily doses of VX-135 in combination with daclatasvir once daily (60 mg) for 12 weeks of total treatment. Twenty-three people with chronic genotype 1 hepatitis C who were new to treatment (treatment-naïve) and did not have liver cirrhosis were enrolled in these cohorts. More than 75% of all patients enrolled had genotype 1a HCV. The majority of adverse events observed in the study were mild. The most common adverse events observed in greater than 10 percent of patients across the study were fatigue, headache and nausea.

VX-135 is a uridine nucleotide analogue pro-drug designed to inhibit the replication of the hepatitis C virus by acting on the NS5B polymerase. Vertex gained worldwide rights to the compound in Phase II studies, through an exclusive licensing agreement signed with Alios BioPharma in June 2011.