Conatus Pharmaceuticals Inc. announced today 24-week interim results from a clinical trial with CTS-1027 in combination with Peginterferon Alpha-2a (Pegasys®) and ribavirin (Copegus®) in a treatment experienced, hepatitis C virus (HCV) null-responder patient population. Null-responder patients are the most difficult to treat patient population and are clinically defined as those patients failing to achieve an early virologic response (EVR) when undergoing treatment with the current standard of care (SOC; pegylated interferon and ribavirin). EVR is defined as at least a 2 log decline in HCV-RNA by week 12 of SOC treatment. The CTS-1027-04 clinical trial enrolled 67 HCV genotype 1 null-responder patients. The clinical trial is a single arm and open label design with sustained viral response (SVR; no detectable virus 24 weeks after the end of treatment) as its primary end point. At week 12, 51% (31/61) of patients receiving 15 mg twice a day of CTS-1027 in addition to standard doses of Pegasys® and Copegus® achieved an EVR on a per protocol (PP) basis. HCV-RNA was below quantifiable limit (BQL) in 5 patients (8.2%, PP) at week 12 and increased to 17 patients (34%, 17/50, PP) at week 24. This clinical trial is ongoing and final SVR results are expected in 2011.
Data from the CTS-1027-04 clinical trial were presented at the 46th annual meeting of the European Association for the Study of the Liver (EASL) held in Berlin, Germany, as Abstract 468. The full abstract is available at www.conatuspharma.com.
Consistent with expectations, the majority of patients tested for genetic analysis of IL-28B (95%, 58/61) carried the CT or TT allelic variant. Patients possessing these genetic variants are predicted to be less responsive to the antiviral actions of interferon.