Enanta is leveraging its early success with its licensed HCV products to become a leader in viral and liver diseases. Enanta’s research and development efforts are currently focused on the following disease targets: respiratory syncytial virus (RSV), hepatitis B virus (HBV), SARS-CoV-2 and human metapneumovirus (hMPV). For an overview of our research, please see our Pipeline.


RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children under one year of age in the United States. There is currently no effective treatment available for RSV infection.

Enanta’s research in RSV is primarily focused on non-fusion inhibitors that target virus replication. Enanta's lead candidate, EDP-938, an N-protein inhibitor with Fast Track Designation from the FDA, has been studied in a Phase 2 challenge study with results demonstrating that EDP-938 achieved highly statistically significant (p < 0.001) reductions in viral load and in resolution of clinical symptoms compared to placebo in in healthy adults infected RSV. Based on those results, EDP-938 is being evaluated in a broad clinical development program, consisting of three trials. RSVP, a Phase 2b study in adult outpatients with community acquired RSV has completed enrollment and data is expected in the second quarter of 2022. RSVTx, a Phase 2b study in in adult hematopoietic cell transplant recipients with RSV and RSVPEDs, a Phase 2 study in pediatric RSV patients, are ongoing with enrollment expected to continue into 2023. Learn more

Enanta Research


Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus. It is estimated that 250 million people worldwide are chronically infected, and 15-25% of patients with chronic HBV infection develop chronic liver disease, including cirrhosis, liver cancer, or liver decompensation.

Enanta has selected EDP-514, an inhibitor of the HBV core protein as its first clinical candidate. Learn more


Discovered in 2001, hMPV is in the same paramyxovirus family as RSV. It is the second most common cause of lower respiratory tract infection in children of less than five years of age behind RSV and is associated with greater than 20,000 hospitalizations in the U.S every year. It also presents a significant health challenge in the elderly and immunocompromised individuals with more than 100,000 hospitalizations annually.

Enanta has discovered a series of novel small molecular inhibitors of hMPV with nanomolar EC50 in vitro. These compounds are currently under lead optimization, with the goal of identifying a potential drug candidate for preclinical and clinical proof-of-concept studies. Clinical candidate selection is targeted for the second half of 2022. Learn more


The pandemic coronavirus disease COVID-19 is caused by the infection of a novel human coronavirus, severe acute respiratory syndrome-coronavirus (SARS-CoV-2). This is only the seventh known coronavirus that infects humans. SARS-CoV-2 causes serious infection, manifested by fever and pneumonia, leading to acute respiratory distress syndrome.

Enanta is developing EDP-235, its lead oral protease inhibitor specifically designed for the treatment of COVID-19. Enanta expects to initiate a Phase 1 single and multiple ascending dose study to evaluate the safety, tolerability, and pharmacokinetics of EDP-235 in healthy volunteers in February 2022. Learn more