Merck (NYSE: MRK), known as MSD outside of the United States and Canada, announced the presentation of interim data from the ongoing C-WORTHY Study, a Phase II clinical trial evaluating the efficacy and safety of an all-oral regimen combining once-daily MK-5172, an investigational hepatitis C virus (HCV) NS3/4A protease inhibitor, and MK-8742, an investigational HCV NS5A replication complex inhibitor, with or without twice-daily ribavirin, administered for 12 weeks to treatment-naïve, non-cirrhotic patients with HCV genotype 1a and 1b infection. The interim data show that the administration of MK-5172 and MK-8742 in combination is associated with a sustained virologic response (lack of detectable and quantifiable HCV) 12 weeks following the end of study therapy (SVR12). Merck previously announced that the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation to MK-5172/MK-8742 for treatment of chronic HCV infection.
“We are encouraged by these preliminary data for the combination of MK-5172 and MK-8742,” said, Dr. Eliav Barr, vice president, Infectious Diseases, Merck Research Laboratories. “These data provide further support that we can advance these candidates, which are currently in Phase IIB clinical development, into a broader evaluation in a diverse range of HCV patients.”
In the C-WORTHY Study, 65 patients (45% male, 11% African American, and 58% genotype 1a infection) were enrolled in one of three 12-week treatment arms (see TABLE). The ribavirin (RBV) arms were stratified by genotype 1a versus genotype 1b. The RBV-free arm included only genotype 1b-infected patients. Virologic response was assessed each week during treatment and at 2, 4, 8, 12 and 24 weeks after the end of treatment. The primary efficacy endpoint of the trial was the proportion of patients who achieved sustained virologic response at post-treatment follow-up week 12 (SVR12).
The primary analysis population was per protocol, including patients who did not have protocol violations and had received the correct study medications. A total of 58/65 enrolled patients met these criteria (see TABLE).