To date, nine clinical studies have been completed by Idun and Pfizer with over 500 people receiving one or more doses of the drug.

Several Phase 1 trials to assess safety, tolerability and pharmacokinetics of emricasan, one of the IV formulation and five of the oral formulation, were completed. Emricasan was well tolerated and a maximum tolerated dose was not identified. Emricasan did not reduce liver enzyme levels in normal volunteers. However, emricasan administration in liver impaired patients resulted in reductions in liver enzyme levels (ALT & AST).

A Phase 2a clinical trial of an oral formulation of emricasan was completed in patients infected with HCV, most of whom had failed existing approved treatments. Various doses and dosing regimens ranging from 25 milligrams to 200 milligrams once a day (QD), and 50 to 100 milligrams twice a day (BID) were examined during a two-week dosing period. All doses of the drug lowered ALT and AST by the end of the treatment period and were well tolerated.

Comparable results were obtained in a trial which dosed patients for 3 months.

A small group of patients with fatty liver disease, and a group with HBV were evaluated as supplemental cohorts of the Phase 2a HCV clinical trial. Aminotransferase reductions were readily observed during treatment with emricasan in both groups.

A Phase 2 trial was conducted to assess the utility of emricasan on CI/WR injury during human liver transplantation. Emricasan, when administered in cold storage and flush solutions during liver transplantation, offered local protection against CI/WR-mediated apoptosis and injury, but this was not observed when emricasan was administered to the patient. No safety signals of concern were seen in the study and the adverse events were generally reflective of the patient population under study.