Vertex Pharmaceuticals announced that its VX-135 and Bristol-Myers Squibb’s daclatasvir likely cured 83 percent of people with genotype 1 of hepatitis C virus (HCV). The results are respectable but hardly stellar in comparison with various competitor drugs, most notably Gilead Sciences’ Sovaldi (sofosbuvir), which has boasted near-perfect cure results in Phase III trials of interferon- and ribavirin-free combination therapy.

The open label study enrolled 23 treatment-naive people with genotype 1 of hep C who did not have cirrhosis and split them into two cohorts: 12 received 200 milligrams of the nucleotide analogue polymerase inhibitor VX-135 and 60 mg of the NS5A replication complex inhibitor daclatasvir, and 11 received 100 mg of VX-135 and 60 mg of daclatasvir. Both cohorts were treated for 12 weeks.

Ten of the 12 participants (83 percent) in the 200 mg cohort achieved a sustained virologic response four weeks after completing treatment (SVR4; SVR12 is considered a cure). Eight out of the 11 participants (73 percent) in the 100 mg cohort achieved an SVR4.

The majority of the side effects were mild. The most common, experienced by more than 10 percent of the participants, were fatigue, headache and nausea.

“We are encouraged by these initial Phase IIa data for VX-135 in combination with another direct-acting antiviral medicine,” Robert Kauffman, MD, PhD, senior vice president and chief medical officer at Vertex, said in a release. “We believe that VX-135 has the potential to play an important future role in the treatment of hepatitis C, and we are currently evaluating these data with BMS to determine the next steps for this combination in people with hepatitis C, including people with genotypes 1 and 3.”

Vertex will present future results from this ongoing study at an upcoming medical meeting.

To read the Vertex release, click here.