SAN DIEGO, April 12, 2011 — Conatus Pharmaceuticals Inc. today announced an additional $7.5 million investment by MPM Capital of South San Francisco, CA. The Series B Preferred Stock financing is now closed with a total of $32.5 million of capital raised. The first closing was completed in early February, 2011. Jim Scopa from MPM will join the Conatus Board of Directors.

Conatus will use the proceeds to advance the clinical development of CTS-1027, a novel clinical-stage drug candidate the Company licensed from F. Hoffman-La Roche, Ltd. and the subject of multiple Phase 2 clinical trials in hepatitis C (HCV)-infected patients.

“We’ve watched the progress at Conatus and believe that CTS-1027 could make a significant difference in the treatment of HCV infection. MPM also expects to provide other resources, both strategic and clinical, to assist the management team in the execution of its business plan”, said Jim Scopa, Managing Director of MPM Capital.

“The additional investment by MPM enables Conatus to move ahead assertively with its confirming Phase 2b clinical trial of CTS-1027 started in January 2011 as well as allowing for a thorough evaluation of the development compounds of Idun Pharmaceuticals acquired in 2010,” said Steven J. Mento, Ph.D.

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.