Merck & Co’s investigational hepatitis C drug has shown favourable results in phase III trials.
The C-EDGE CO-STAR trial examined the efficacy and safety of the once-daily tablet elbasvir/grazoprevir (50mg/100mg) in patients with chronic hepatitis C infection who inject drugs and are receiving opioid agonist therapy (OAT).
The study found that that 95% of patients treated with the drug for 12 weeks, achieved sustained virologic response 12 weeks after the completion of treatment.
Dr Eliav Barr, vice president of infectious diseases at Merck, said: “Limited research has been conducted in people with chronic hepatitis C virus infection undergoing treatment for injection drug use because of the perceived challenges and complexities involved in treating this population.
“This is one of the largest clinical trials to date evaluating an all-oral, once-daily ribavirin-free investigational treatment regiment for patients with chronic hepatitis C virus infection on opiod agonist therapy and reflects Merck’s ongoing commitment to study the diverse real-world population of people living with the disease.”
Of the 301 patients in the trial, 76% had a GT1a infection, 21% had cirrhosis and 7% had HIV/HCV co-infection. However, adherence to treatment was high with 97% of patients taking at least 95% of their study medication over the 12 weeks of therapy.
Elbasvir is a HCV NS5A replication complex inhibitor and grazoprevir is a HCV NS3/4A protease inhibitor. The combination was granted Breakthrough Therapy Designation and given Priority Review by the FDA earlier this year.
In the United States, up to 84% of the population on OAT have been infected with HCV and injection drug use is the most common risk factor for chronic HCV infection.
Additionally, rates of transmission and reinfection are higher among injection drug users than in other people with HCV.
Hepatitis C affected approximately 100 million people worldwide in 2012 with Gilead capturing much of the market, achieving sales of $4.7bn last year for its hepatitis C vaccine.