Merck Announces Results From Phase 3 Studies of ZEPATIER™ in Chronic Hepatitis C Patient Populations at The International Liver Congress™

Merck, known as MSD outside of the United States and Canada, today announced the presentation of results from two Phase 3 clinical trials evaluating ZEPATIER™ (elbasvir and grazoprevir) 50mg/100mg tablets in chronic hepatitis C (HCV) patients with inherited blood disorders (C-EDGE IBLD) and in patients with a history of intravenous drug use who are receiving opioid agonist therapy (C-EDGE CO-STAR), respectively.

Results from C-EDGE IBLD demonstrated high rates of sustained virologic response (SVR) 12 weeks after the completion of treatment (SVR12, considered virologic cure) and a safety profile consistent with that observed in prior studies (abstract #SAT-128). Findings from C-EDGE CO-STAR showed a high rate of SVR 24 weeks after completion of treatment (SVR24) for the baseline chronic HCV infection and provided insights into the incidence of reinfection in this high risk population (abstract #SAT-163). The SVR24 data confirm the C-EDGE CO-STAR SVR12 results unveiled at The Liver Meeting® in November 2015. ZEPATIER – Merck’s once-daily, fixed-dose combination tablet indicated with or without ribavirin (RBV) for the treatment of chronic HCV genotype (GT) 1 or GT4 infection in adults – was approved by the U.S. Food and Drug Administration in January 2016, based in part on prior studies from the Phase 3 program. Data from these additional Phase 3 studies were presented today at The International Liver CongressTM 2016 (ILC).

“To reduce the global burden and potential spread of chronic hepatitis C, it is important that we develop evidence about meaningful options for those patients for whom treatment may be challenging,” said Dr. Eliav Barr, vice president, infectious diseases, Merck Research Laboratories. “These data from Merck’s broad clinical development program underscore the company’s commitment to evaluating ZEPATIER in historically underserved and understudied chronic hepatitis C populations, such as patients with inherited blood disorders or those receiving opioid agonist therapy.”

C-EDGE IBLD Overview and Findings

C-EDGE IBLD is a Phase 3 randomized, double-blind, placebo-controlled study evaluating treatment with ZEPATIER (elbasvir and grazoprevir) in patients with chronic HCV GT1, GT4 or GT6 infection and inherited blood disorders, including hemophilia A/B, von Willebrand disease, beta thalassemia and sickle cell anemia. Patients were randomized in a 2:1 ratio to either an immediate treatment group (ITG; 12 weeks of ZEPATIER) or deferred treatment group (DTG; 12 weeks of placebo as control arm, followed by 12 weeks of open-label ZEPATIER). The primary efficacy endpoint for the study was the proportion of patients in the ITG who achieved SVR12. Safety and tolerability were evaluated by comparing subjects receiving ZEPATIER in the ITG (n=107) to those receiving placebo in the DTG (n=52).

Following 12 weeks of treatment with ZEPATIER, 93 percent of patients in the ITG (100/107) achieved SVR12 (virologic cure). Six patients relapsed following twelve weeks of treatment; five of these patients (3 GT1a, 1 GT1b and 1 GT4) had detectable NS5A resistance-associated polymorphisms at baseline.1 The study did not evaluate other ZEPATIER-based dosage regimens or durations.

The most common (greater than 10%) adverse events (AEs) among patients receiving ZEPATIER for 12 weeks in C-EDGE IBLD, compared with those receiving placebo, were headache (21%, 12%) and fatigue (17%, 8%). No patient receiving ZEPATIER discontinued due to AEs, compared with one patient receiving placebo. Three patients (3%) receiving ZEPATIER and six patients (12%) receiving placebo reported a total of 12 serious AEs. Treatment did not affect pre-defined hematological parameters and did not interfere with the management of underlying blood disorders.

C-EDGE CO-STAR Overview and Findings

C-EDGE CO-STAR is a Phase 3 double-blind, placebo-controlled study evaluating treatment with ZEPATIER in patients with chronic HCV GT1, GT4 and/or GT6 infection who are on opioid agonist therapy (i.e., methadone, buprenorphine). Efficacy (SVR12) and safety results from the trial were previously presented at The Liver Meeting® in November 2015. Results presented at ILC this week included secondary efficacy endpoint (SVR24) and reinfection analyses. A separate analysis of health-related quality of life data from C-EDGE CO-STAR was also presented this week at ILC.

The study included an immediate treatment group (ITG) that received blinded ZEPATIER (elbasvir and grazoprevir) for 12 weeks (n=201) and a deferred treatment group (DTG) that received 12 weeks of placebo (control arm) (n=100), followed by 12 weeks of open-label ZEPATIER (n=95). The secondary efficacy analysis evaluated SVR24 in the modified full analysis set (n=271), which included patients from both treatment groups who received ZEPATIER for 12 weeks and completed 24 weeks of follow up, excluding those who discontinued for non-treatment related reasons. An additional analysis evaluated the reinfection incidence among all patients who completed active study therapy (n=296).