CROI 2013An interim analysis showed that two second-generation, direct-acting antiviral hepatitis C virus (HCV) therapies simeprevir and sofosbuvir led to high cure rates in people who had previously failed a hep C therapy. Representatives from Janssen Pharmaceuticals announced findings from this Phase IIa open-label COSMOS study at the 20th annual Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta. In the study, the protease inhibitor simeprevir (TMC435), given once daily along with Gilead Sciences’ investigational nucleotide inhibitor sofosbuvir (GS-7977), with or without ribavirin for 12 and 24 weeks. All 80 study participants had genotype 1 of hep C, mild to moderate liver fibrosis and were prior null-responders to antiviral treatment.  

The study randomly divided the participants into four arms:

  • 15 took simeprevir and sofosbuvir for 24 weeks.
  • 24 took simeprevir, sofosbuvir plus ribavirin for 24 weeks.
  • 15 took simeprevir and sofosbuvir for 12 weeks.
  • 27 took simeprevir, sofosbuvir plus ribavirin for 12 weeks.
In the 24-week arms, 66.7 percent of those taking ribavirin (one patient dropped out of the study because of an adverse event, and another person withdrew consent) and 100 percent of those without ribavirin achieved a sustained virologic response four weeks after completing therapy (SVR4, considered a cure). Among those in the 12-week arms, 96.3 percent of those taking ribavirin and 92.9 percent of those taking the regimen without ribavirin achieved an SVR4.


To read the conference abstract, click here.