Elbasvir / Grazoprevir Superior to Sofosbuvir Plus PegIFN and Ribavirin in Phase 3 Hepatitis Trial

Virological cure achieved in 99% of patients

Results have been reported from the C-EDGE Head-to-Head trial, a comparative, phase 3, open-label study evaluating the efficacy and safety of Zepatier (elbasvir and grazoprevir, Merck) 50-mg/100-mg tablets versus a regimen of sofosbuvir 400-mg tablets plus peginterferon and ribavirin (pegIFN/RBV) in treatment-naïve and pegIFN/RBV treatment-experienced patients with chronic hepatitis C virus (HCV) genotype (GT) 1 or GT4 infection.

In that study, Zepatier demonstrated superiority on efficacy and safety endpoints compared with sofosbuvir plus pegIFN/RBV. In the full analysis set (N = 255), the efficacy endpoint of a sustained virological response at 12 weeks after the completion of therapy (SVR12, considered a virological cure) was achieved in 128 of 129 patients (99%) receiving Zepatier versus 114 of 126 patients (90%) receiving sofosbuvir plus pegIFN/RBV.

Zepatier was approved in January 2016 for the treatment of chronic HCV GT1 or GT4 infections in adults, with or without RBV.

The C-EDGE Head-to-Head trial, conducted in Europe, was designed to evaluate the efficacy and safety of 12 weeks of treatment with Zepatier compared with that of a 12-week regimen of sofosbuvir plus pegIFN/RBV. The trial enrolled treatment-naïve and pegIFN/RBV treatment-experienced patients, with or without cirrhosis, with chronic HCV GT1 or GT4 infections. A total of 255 GT1- or GT4-infected patients were randomly assigned to 12 weeks of treatment with either Zepatier 50-mg/100-mg tablets (n = 129) or sofosbuvir 400-mg tablets plus pegIFN/RBV (n = 126). At baseline, 17% of the patients had compensated cirrhosis; 67% had HCV RNA greater than 800,000 IU/mL; 99% were white; 78% had the interleukin 28B non-CC genotype; and approximately 25% had failed prior treatment with pegIFN/RBV (10% prior null responders, 5% prior partial responders, and 10% prior relapsers).

In the Zepatier group, one patient (1%) withdrew from the study after completing treatment. There were no virological failures among the Zepatier-treated patients. In the sofosbuvir plus pegIFN/RBV group, virological failure occurred in 11 patients (9%), and one patient (1%) withdrew from the trial after the first week of treatment.

Zepatier is not for use in patients with moderate or severe hepatic impairment (Child–Pugh B or C). Zepatier is also not for use with organic anion transporting polypeptides 1B1/3 (OATP1B1/3) inhibitors (e.g., atazanavir, darunavir, lopinavir, saquinavir, tipranavir, or cyclosporine); strong cytochrome P450 3A (CYP3A) inducers (e.g., carbamazepine, phenytoin, rifampin, St. John’s Wort); or efavirenz.