Enanta Pharmaceuticals, Inc., (NASDAQ: ENTA) a research and development-focused biotechnology company dedicated to creating small molecule drugs in the infectious disease field, today announced that additional data from AbbVie’s M13-393 study, referred to as PEARL-I, will be presented in an oral presentation at 5:15 p.m. ET today at The Liver Meeting, the 64 th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) in Washington, D.C. In PEARL-I, SVR12 rates of 95% (40/42) in hepatitis C (HCV) GT-1b treatment-naïve patients and 90% (36/40) among prior null responders will be presented in this intent-to-treat analysis. Two patients in the treatment-naive arm did not achieve SVR12 due to loss to follow up. In the null responder arm, one patient experienced breakthrough and three patients relapsed. PEARL-I is a phase-2b, interferon-free, 320 patient study being conducted by AbbVie to evaluate the once-daily, two-DAA regimen consisting of ABT-450/r (protease inhibitor plus ritonavir) + ABT-267 (AbbVie’s NS5A inhibitor) in HCV treatment-naïve patients and treatment-experience patients. GT-1b treatment arms are ribavirin-free and also include cirrhotic patients while GT-4 arms explore treatment with and without ribavirin. “We are very encouraged by the strong SVR12 rates from this simplified 2-DAA, once-daily regimen that includes our lead HCV protease inhibitor, ABT-450,” commented Jay R. Luly, Ph.D., President and Chief Executive Officer. “We look forward to data from Phase 3 studies of three-DAA regimens containing ABT-450 being reported in the coming months.” Protease Inhibitor Collaboration with AbbVie (formerly the research-based pharmaceutical business of Abbott Laboratories) In December 2006, Enanta and Abbott announced a worldwide agreement to collaborate on the discovery, development and commercialization of HCV NS3 and NS3/4A protease inhibitors and HCV protease inhibitor-containing drug combinations. ABT-450 is a protease inhibitor identified as a lead compound through the collaboration. Under the agreement, AbbVie is responsible for all development and commercialization activities for ABT-450. Enanta received $57 million in connection with signing the collaboration agreement, has received $55 million in subsequent clinical milestone payments, and is eligible to receive an additional $195 million in payments for regulatory milestones, as well as double-digit royalties worldwide on any revenue allocable to the collaboration’s protease inhibitors. Also, for any additional collaborative HCV protease inhibitor product candidate developed under the agreement, Enanta holds an option to modify the U.S. portion of it rights to receive milestone payments and worldwide royalties. With this option, Enanta can fund 40 percent of U.S. development costs and U.S. commercialization efforts (sales and promotion costs) for the additional protease inhibitor in exchange for 40 percent of any U.S. profits ultimately achieved after regulatory approval instead of receiving payments for U.S. commercial regulatory approval milestones and royalties on U.S. sales of that protease inhibitor.