Medivir AB and Idenix Announce Phase-2 Results with Simeprevir, Ribavirin, and Samatasvir in Treating Hepatitis C

Close on the heels of Vertex Pharmaceuticals’ and Bristol-Myers Squibb’s announcement of 4-week sustained viral response (SVR4) results with VX-135 and daclatasvir, Medivir AB and Idenix Pharmaceuticals, Inc announce SVR4 results with simeprevir, ribavirin, and samatasvir.

On January 13, Medivir AB announced sustained viral response 4 weeks after the end of therapy (SVR4) in the HELIX-1 phase-2 clinical trial. The announcement of SVR4 results comes parallel to SVR4 results with another combination treatment—VX-135 and daclatasvir—through a partnership between Vertex and Bristol-Myers Squibb.

Medivir’s simeprevir and Idenix’s samatasvir (IDX719) with ribavirin background therapy is unlike the combination under development by Vertex and Bristol-Myers Squibb, however, in that samatasvir and simeprevir are used with ribavirin, whereas the VX-135 and daclatasvir combination is not used with ribavirin.

In the phase II trial, patients received 12 weeks of therapy with simeprevir, ribavirin, and samatasvir to attain an 85% rate of SVR4 in 17 of 20 patients with genotype-1b or -4 hepatitis C virus. The ongoing HELIX trials will evaluate whether this 4-week response rate remains durable through a 12- or 24-week endpoint, which is the standard of evaluating functional cure rates in hepatitis C therapy.

Simeprevir is already available in the United States as a treatment for hepatitis C. More than 3700 patients have received simeprevir in clinical trials. To date, no treatment-emergent serious adverse events have been observed with the partner drug, samatasvir.

Medivir and Janssen began a collaboration on simeprevir for hepatitis C in January 2013. It is too early to determine what the results will be with the treatment combination offered by Idenix and Medivir, although initial results are promising. The competition for the hepatitis C treatment space among several top companies is welcome news to millions of patients with hepatitis C in the United States and around the world.