Merck announced the publication of results from C-EDGE CO-STAR. C-EDGE CO-STAR is a Phase 3 trial evaluating the use of ZEPATIER™ (elbasvir and grazoprevir) 50 mg/100 mg tablets in patients with chronic hepatitis C (HCV) genotype (GT) 1, GT4, and GT6 infection receiving opioid agonist therapy (OAT) (methadone and buprenorphine), commonly used to treat opioid addiction.
The results, recently published online in the Annals of Internal Medicine, showed treatment with 12 weeks of ZEPATIER resulted in high rates of sustained virologic response 12 weeks after the completion of therapy (SVR12, considered virologic cure based on undetectable HCV RNA levels). These results and full study design were previously presented at The Liver Meeting® in November 2015.
“C-EDGE CO-STAR is the first phase 3 clinical trial dedicated to evaluating direct-acting antiviral therapy for chronic hepatitis C infection in patients on opioid agonist therapy without excluding patients actively using drugs with high abuse potential,” said Dr. Alain Litwin, professor of medicine and psychiatry and behavioral sciences at Albert Einstein College of Medicine, New York. “This study demonstrates that people who inject drugs can be effectively treated with direct-acting antiviral therapy.”
The published efficacy results from the randomized, double-blind, placebo-controlled C-EDGE CO-STAR trial showed 92 percent (184/201) of patients receiving ZEPATIER for 12 weeks in the study’s immediate treatment group achieved SVR12, with comparable rates across GT1a (94%, 144/154), GT1b (93%, 28/30) and GT4 (92%, 11/12) patients; in the limited number of GT6 patients, SVR12 was 20 percent (1/5). These results classify patients who cleared their baseline infection but subsequently acquired a new infection as treatment failures; previously presented results from this trial considered these patients as treatment successes, according to the study protocol. A supportive analysis showed that the vast majority of patients were adherent to therapy, despite ongoing use of drugs of potential abuse (e.g., cocaine, heroin, amphetamines) by the majority of patients throughout the trial. The rates of adverse events were generally comparable between active treatment and placebo groups, with the most common adverse events (greater than 10%) in both groups including fatigue (16%, 20%), headache (12%, 13%) and nausea (11%, 9%), respectively. Secondary efficacy endpoint (SVR24) and reinfection analyses were presented at The International Liver Congress™ in April 2016.
“Merck continues to take a leadership role in exploring the potential to treat chronic hepatitis C infection in underserved and undertreated patient populations, including those who continue to use illicit drugs,” said Dr. Eliav Barr, vice president, infectious diseases, Merck Research Laboratories. “These findings contribute to the robust body of evidence supporting the efficacy and safety profile of ZEPATIER in a broad range of patients with chronic hepatitis C genotype 1 or genotype 4 infection.”
Filed Under: Drug Discovery