Zepatier is a fixed-dose combination therapy of elbasvir and grazoprevir for chronic hepatitis C.
Injection drug users can be effectively treated for hepatitis C with the new generation of antiviral medications.
Positive results from a phase 3 trial evaluating elbasvir and grazoprevir (Zepatier) in chronic hepatitis C (HCV) patients receiving opioid agonist therapy (OAT) were recently published in the Annals of Internal Medicine. The double-blind, placebo-controlled, randomized C-EDGE CO-STAR trial evaluated 50-mg/100 mg Zepatier tablets for 12 weeks in patients with HCV genotype (GT) 1, GT4, and GT6 infection who were receiving OAT (methadone and buprenorphine).
“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 of infectious diseases at 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.”
OAT is commonly used to treat opioid addiction. Zepatier is a fixed-dose combination therapy, consisting of the HCV NS5A inhibitor elbasvir, and the HCV NS3/4A protease inhibitor grazoprevir.
The therapy is indicated with or without ribavirin for chronic HCV GT 1 or 4 infection, but is not indicated to treat chronic HCV GT6 infection. The results of the C-EDGE CO-STAR trial showed that patients administered Zepatier for 12 weeks in the immediate treatment group achieved SVR12.
There were comparable rates seen 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% (1/5).
In a supportive analysis, it revealed that a majority of the participants were adherent to therapy, even though a majority of patients had ongoing use of drugs of potential abuse (cocaine, heroin, amphetamines) throughout the trial. In both groups, the most common adverse events (AEs) greater than 10% were fatigue, headache, and nausea.
The rates of AEs were generally comparable between active treatment and placebo groups.
“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,” Dr. Alain Litwin, professor of medicine and psychiatry and behavioral sciences at Albert Einstein College of Medicine, said in a press release. “This study demonstrates that people who inject drugs can be effectively treated with direct-acting antiviral therapy.”