SAN DIEGO — Conatus Pharmaceuticals Inc. announced today the treatment of the first patient in a multi-center Phase 2b clinical trial evaluating CTS-1027 in combination with Peginterferon Alfa-2a (Pegasys®) and ribavirin (Copegus®) in a treatment experienced, hepatitis C (HCV) null responder patient population. Safety, tolerability, and antiviral activity of the triple combination will be assessed after up to 48 weeks of therapy.

CTS-1027 is an oral, small molecule compound that inhibits the activity of key members of a class of protease enzymes, the matrix metalloproteinases or MMPs. CTS-1027 has been shown to reduce and/or block HCV infection in in vitro preclinical models and more recently, has displayed the potential to amplify the effectiveness of existing therapies in difficult to treat HCV-infected patients. This is in addition to CTS-1027’s anti-inflammatory and anti-fibrotic effects which have been well established in models of acute hepatitis and liver fibrosis.

“Our previous clinical trials indicate that CTS-1027 used in combination with existing standard-of-care HCV drugs has the potential to impact the second phase of HCV virus inhibitory kinetics in patients. This phase is associated with the gradual reduction and replacement of HCV infected cells by new uninfected liver cells. While reducing HCV virus production in infected cells is extremely important, eliminating HCV-infected cells is crucial to curing HCV,”

said Dr. Steven J. Mento, President and CEO of Conatus.

“We believe that CTS-1027 represents a novel approach to treating HCV disease and look forward to developing this drug candidate in combination with the existing standard-of-care drugs as well as the new antiviral drugs under development.”

“We have established a collaborative relationship with key opinion leaders and clinical investigators in the hepatitis community,”

said Ms. MiRa Huyghe, Vice President of Clinical Development of Conatus.

“We are encouraged by our investigators’ interest in CTS-1027 and together with our investigators look forward to offering a new treatment option for HCV null responders.”

“We are excited to participate in this Phase 2b trial of CTS-1027,”

said Dr. Paul J. Pockros, Head, Division of Gastroenterology/Hepatology at The Scripps Clinic and Director of the SC Liver Research Consortium in La Jolla, CA. 

“Current treatment options for HCV null responders are very limited. We believe CTS-1027 may enhance the effectiveness of pegylated interferon and ribavirin in this difficult to treat patient population.”

This clinical trial is a placebo-controlled, multicenter, double-blind, randomized trial of Peginterferon Alfa-2a (Pegasys®) and ribavirin (Copegus®) with or without CTS-1027 in HCV null responders. Dosing will last for up to 48 weeks. The trial will also examine whether higher dose levels of CTS-1027 will improve on previously observed results. The Company expects approximately 260 patients to be enrolled. The clinical trial will be conducted at up to fifty medical centers in the U.S. Additional information about the trial can be found at: www.clinicaltrials.gov (Identifier NCT01051921) or http://www.clinicaltrials.gov/ct2/results?term=cts-1027.

Conatus Pharmaceuticals Inc. is a privately-held biopharmaceutical company engaged in the development of innovative human therapeutics to treat liver disease and oncology. Conatus’ lead drug candidate, CTS-1027, is in multiple Phase 2 clinical trials for the treatment of hepatitis C virus (HCV). Conatus was founded by the executive management team of Idun Pharmaceuticals in July 2005 following the sale of Idun to Pfizer. For additional information, please visit www.conatuspharma.com.

Pegasys® and Copegus® are registered trademarks of F. Hoffman-La Roche, Inc.