Enanta Pharmaceuticals Announces Publication in The New England Journal of Medicine of Phase 2a Human Challenge Study Data of EDP-938 for the Treatment of Respiratory Syncytial Virus (RSV)


EDP-938 is currently being evaluated in Phase 2 studies in pediatric patients and hematopoietic stem cell transplant recipients with RSV

On track to report key data from RSVP, a Phase 2b study in adults with community-acquired RSV infection, in the second quarter of 2022

WATERTOWN, Mass.–(BUSINESS WIRE)–Enanta Pharmaceuticals, Inc. (NASDAQ: ENTA), a clinical-stage biotechnology company focused on creating small molecule drugs for viral infections and liver disease, announced today that data from its Phase 2 human challenge study has been published in The New England Journal of Medicine (NEJM).

“The publication of positive results from our Phase 2a human challenge study of EDP-938 in NEJM demonstrates the importance of our work in developing EDP-938 as a potential treatment option for patients with RSV, a deadly virus affecting children, the elderly, and immunocompromised individuals for whom there is no vaccine or therapeutic treatment,” said Jay R. Luly, Ph.D., President and CEO of Enanta Pharmaceuticals. “EDP-938 is currently being evaluated in a large clinical program across multiple patient populations, and we look forward to further development of this important therapy to bring us closer to a treatment for patients. with RSV.

The Phase 2a study was a randomized, double-blind, placebo-controlled human challenge study in healthy adult subjects inoculated with RSV. Once RSV infection was confirmed, subjects were randomized to receive either a once-daily (QD) dose of 600 mg of EDP-938 or a single loading dose of 500 mg (LD) followed by 300 mg twice daily (BID) dose of EDP-938. 938, or placebo for five days. The primary endpoint was the change in viral load (determined by RT-qPCR), measured by area under the curve (AUC) from the starting dose on day 12 in the infected intention-to-treat population. A key secondary endpoint measured the reduction in AUC of the total symptom score.

the NEJM The publication highlighted the results of the Phase 2 human challenge study in which the primary efficacy endpoint was met with a highly statistically significant (pten copies/mL in the QD arm and 217.71 ± 217.55 hours x Logten copies/mL in the BID arm, compared to 790.15 ± 408.80 hours x Logten copies/mL in the placebo arm (p

For the key secondary efficacy endpoint, a highly statistically significant reduction was observed in the total symptom score for each of the EDP-938 dosing groups (124.47 hours x score ±115.60 for the QD arm and 181.75 ± 248.42 hours x score for the BID arm, compared to 478.75 ± 422.29 hours x score in the placebo arm (p

EDP-938 demonstrated good pharmacokinetics and mean trough drug concentrations were maintained approximately 20-40 times above the in vitro THIS90 for RSV-infected human cells.

Overall, EDP-938 was generally safe and well tolerated. EDP-938 demonstrated a favorable safety profile over five days of administration through day 28 of follow-up, comparable to placebo for both dosing groups. There were no serious adverse events and no discontinuation of study drug.

About the EDP-938
EDP-938, Enanta’s lead N protein inhibitor, is being developed for the treatment of RSV infection. Receiving Fast Track designation from the United States Food and Drug Administration, EDP-938 differentiates itself from RSV fusion inhibitors because this protein N inhibitor targets the replication machinery of the virus and has demonstrated high barriers to resistance against the virus in vitro. EDP-938 has also been shown to reduce viral load below detection level live. Additionally, protein N inhibitors may be effective treatments at later stages of infection.

About respiratory syncytial virus
RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lungs) and pneumonia in children under one year of age in the United States and an important cause of respiratory disease in the elderly and people immunocompromised.1 According to the Centers for Disease Control and Prevention, virtually all children in the United States become infected with RSV by age 2, and one to two in 100 children under age 6 who are infected with RSV may need ‘to be hospitalized.2 Globally, there are an estimated 33 million cases of RSV per year in children under 5 years of age, with approximately 3 million hospitalizations and up to approximately 120,000 deaths each year from complications associated with RSV. ‘infection.3 RSV poses a significant threat to the health of adults over the age of 65, with 177,000 hospitalizations and 14,000 deaths associated with RSV infections estimated each year.4 In the United States, compared to the flu, RSV causes more than nine times more deaths and more than 15 times more infant hospitalizations.5.6

About Enanta Pharmaceuticals, Inc.
Enanta uses 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 disease. Enanta’s research and development programs include clinical candidates currently in development for the following target diseases: respiratory syncytial virus (RSV), SARS-CoV-2 (COVID-19) and hepatitis B virus ( HBV). Enanta is also conducting research on human metapneumovirus (hMPV).

Enanta’s research and development activities are funded by royalties from hepatitis C virus (HCV) products developed through its collaboration with AbbVie. Glecaprevir, a protease inhibitor discovered by Enanta, is sold by AbbVie in many countries as part of its primary treatment for chronic HCV infection under the trade names MAVYRET® (US) and MAVIRET® (formerly US) (glecaprevir/pibrentasvir). Please visit www.enanta.com for more information.

This press release contains forward-looking statements, including statements regarding the prospects for advancement of EDP-938 for VRS. Statements that are not historical facts are based on management’s current expectations, estimates, forecasts and projections regarding Enanta’s business and the industry in which it operates, and management’s beliefs and assumptions. The statements in this release are not guarantees of future performance and involve certain risks, uncertainties and assumptions, which are difficult to predict. Therefore, actual results may differ materially from what is expressed in these forward-looking statements. Important factors and risks that could affect actual results include: the impact of the development, regulatory and commercialization efforts of others regarding competing treatments for RSV; risks of discovery and development of Enanta’s programs in RSV; the competitive impact of others’ development, regulatory and commercialization efforts in these disease areas; any ongoing impact of the COVID-19 pandemic on business operations and RSV clinical trials; Enanta’s lack of clinical development experience; Enanta’s need to attract and retain senior management and key research and development personnel; Enanta’s need to obtain and maintain patent protection for its product candidates and to avoid potential infringement of the intellectual property rights of others; and other risk factors described or referred to under “Risk Factors” in Enanta’s most recent Form 10-K for the fiscal year ended December 31, 2021, and any other periodic reports more recently filed with the Securities and Exchange Committee. Enanta cautions investors not to place undue reliance on the forward-looking statements contained in this release. These statements speak only as of the date of this release, and Enanta undertakes no obligation to update or revise these statements, except as required by law.


1. Centers for Disease Control & Prevention – Respiratory Syncytial Virus
2. Centers for Disease Control & Prevention – RSV in Infants and Young Children
3. Shi, Ting et al. “Global, regional and national estimates of the disease burden of acute lower respiratory tract infections due to respiratory syncytial virus in young children in 2015: a systematic review and modeling study.” Lancet (London, England) flight. 390,10098 (2017):946-958. doi:10.1016/S0140-6736(17)30938-8
4. Falsey, Ann R et al. “Respiratory syncytial virus infection in older and high-risk adults.” The New England Journal of Medicine flight. 352.17 (2005): 1749-59. doi:10.1056/NEJMoa043951
5.Thompson, William W et al. “Influenza and Respiratory Syncytial Virus Associated Mortality in the United States.” JAMA flight. 289.2 (2003): 179-86. doi:10.1001/jama.289.2.179
6. Zhou, Hong et al. “Influenza and Respiratory Syncytial Virus-Associated Hospitalizations in the United States, 1993-2008.” Clinical infectious diseases flight. 54.10 (2012): 1427-36. doi:10.1093/cid/cis211


About Author

Comments are closed.