SAN DIEGO, May 09, 2007 — Conatus Pharmaceuticals Inc. today completed the $22 million second closing of the $27.5 million Series A Preferred Stock private placement announced in January this year. This closing is associated with the achievement of a pre-clinical milestone with CTS-1027, the Company’s novel clinical stage drug candidate. “CTS-1027 is a potent and effective compound in a well established model of liver damage. This drug represents an exciting first-in-class approach for patients suffering from liver disease,” said Alfred P. Spada, Ph.D., Senior Vice President of Research and Development at Conatus. The investors are Aberdare Ventures, Advent Venture Partners, Bay City Capital, and Gilde Healthcare Partners.

The proceeds will be used for multiple Phase 2 studies in patients with liver disease. The drug will be initially evaluated in patients infected with the Hepatitis C virus (HCV) who have failed existing treatments (refractory to the standard of care) and is scheduled to begin at the end of 2007. Conatus licensed in CTS-1027 from F. Hoffmann-La Roche Ltd in November 2006.

“The Conatus management team pioneered the development of novel drugs to treat inflammation of the liver (hepatitis) and looks forward to bringing CTS-1027 forward into clinical trials for this under-served patient population,” said Steven J. Mento, Ph.D., President and Chief Executive Officer.

Conatus Pharmaceuticals Inc. is a privately-held specialty pharmaceutical company engaged in the development of innovative human therapeutics to treat liver disease. Chronic liver disease affects millions of people worldwide and can be caused by many different conditions or “insults” to the liver including viral infection, obesity, chronic alcohol abuse or autoimmune diseases. Conatus was founded by the executive management team of Idun Pharmaceuticals in July 2005 following the successful sale of Idun to Pfizer.