New Data from Enanta’s Phase 2a Human Challenge Study of EDP-938 for RSV to be Presented at IDWeek™ 2019

• Late-breaker oral presentation of EDP-938 on October 3 at 2:35 pm ET

WATERTOWN, Mass.–(BUSINESS WIRE)–Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA), a research and development-focused biotechnology company dedicated to creating small molecule drugs for viral infections and liver diseases, today announced that new data from its Phase 2a Human Challenge Study of EDP-938 will be presented as a late-breaker oral presentation at IDWeek^™ 2019, October 2-6, 2019 in Washington, D.C. EDP-938 is Enanta’s lead N-protein inhibitor being developed for the treatment of RSV infection. Also being presented is a preclinical poster detailing the pharmacokinetic and pharmacodynamic characterization of EDP-938. Further details will be available on the date of presentation.

Late-Breaker Oral Presentation:

October 3, 2019

Time: 2:35 – 2:45 pm ET

#LB6: “EDP-938, a Novel RSV N-Inhibitor, Administered Once or Twice Daily Was Safe and Demonstrated Robust Antiviral and Clinical Efficacy in a Healthy Volunteer Challenge Study”, Coakley, et.al.

Poster Presentation:

October 3, 2019

12:15 – 1:30 pm ET

#667: “Preclinical Pharmacokinetic and Pharmacodynamic Characterization of EDP-938, a Novel and Potent Non-Fusion Replication Inhibitor of Respiratory Syncytial Virus,” Jiang, et.al.

Further information about IDWeek^™ 2019 can be found at: https://www.idsociety.org/events2/events/2019/October/idweek-2019/.

About Enanta

Enanta is using its robust, chemistry-driven approach and drug discovery capabilities to become a leader in the discovery and development of small molecule drugs for the treatment of viral infections and liver diseases. Enanta’s research and development efforts are currently focused on the following disease targets: respiratory syncytial virus (RSV), non-alcoholic steatohepatitis (NASH)/ primary biliary cholangitis (PBC), and hepatitis B virus (HBV).

Enanta’s research and development activities are funded by royalties from HCV products developed under its collaboration with AbbVie. Glecaprevir, a protease inhibitor discovered by Enanta, is now sold by AbbVie in numerous countries as part of its newest treatment for chronic hepatitis C virus (HCV) infection. This leading HCV regimen is sold under the tradenames MAVYRET^™ (U.S.) and MAVIRET^™ (ex-U.S.) (glecaprevir/pibrentasvir). Please visit www.enanta.com for more information.

Contacts

Investor Contact

Carol Miceli

617-607-0710

[email protected]

Media Contact

Kari Watson

MacDougall Biomedical Communications

781-235-3060

[email protected]