Janssen begins Phase II IMPACT trial of simeprevir combination for hepatitis C treatment

Medivir partner Janssen has started patient enrolment in a Phase II trial (IMPACT) of the NS3/4A protease inhibitor simeprevir to treat patients with hepatitis C genotype 1 and 4 infection and decompensated liver disease.

The open label IMPACT trial is designed to evaluate the efficacy, safety and pharmacokinetics of simeprevir administered once daily in combination with Gilead's nucleotide inhibitor sofosbuvir and Bristol-Myers Squibb's (BMS) NS5A replication complex inhibitor daclatasvir in treatment-naïve and treatment-experienced patients.

During the trial, patients will be given a once-daily combination of simeprevir 150mg, sofosbuvir 400mg and daclatasvir 60mg, for 12 weeks.

The trial's primary efficacy endpoint is the proportion of patients achieving sustained virologic response 12 weeks after the end of treatment (SVR12).

The company said the IMPACT trial represents the first Phase II study concerning the combination of simeprevir, sofosbuvir and daclatasvir in a regimen without pegylated interferon and ribavirin.

Developed jointly by Janssen R&D Ireland and Medivir, simeprevir is a potential treatment for chronic hepatitis C infection as a part of a combination antiviral treatment regimen.

Janssen is responsible for the global clinical development of simeprevir and has exclusive, worldwide marketing rights, except in the Nordic countries. Medivir retains marketing rights for the drug in these countries under the marketing authorisation held by Janssen-Cilag International.

Simeprevir was approved earlier this year to treat chronic hepatitis C infection as part of an antiviral treatment regimen in combination with pegylated interferon and ribavirin in genotype 1 infected adults with compensated liver disease, including cirrhosis.

The drug was approved in Japan in September 2013 and in both Canada and the US in November 2013. It was approved in Russia in March, and in Mexico and Australia in July.