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 Enanta initiated two additional studies: RSVP, a Phase 2b study in adult outpatients with community-acquired RSV and RSVTx, a Phase 2b study in adult hematopoietic cell transplant recipients with acute RSV infection and symptoms of upper respiratory tract infection. Enanta plans to initiate RSVPEDs, a Phase 2 study in pediatric patients, in 2021. 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. Enanta is also developing EDP-721, a potent and selective HBV RNA destabilizer. 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. 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 working to discover direct-acting antiviral drug candidates for patients infected with SARS-CoV-2. The company is focused on polymerase and protease inhibitors and is currently optimizing direct-acting antiviral leads targeting mechanisms that should be effective against emerging spike protein variants. Learn more.