A Phase 2a study to evaluate the efficacy of EDP-323 against RSV in a virus challenge model.
Research type
Research Study
Full title
A Randomised, Phase 2a, Double-Blind, Placebo-Controlled Study to Evaluate the Safety, Pharmacokinetics and Antiviral Activity of Multiple Doses of Orally Administered EDP-323 Against Respiratory Syncytial Virus Infection in the Virus Challenge Model in Healthy Adults
IRAS ID
1007761
Contact name
Timothy Abrahamsen
Contact email
Sponsor organisation
Enanta Pharmaceuticals, Inc.
ISRCTN Number
ISRCTN62572873
Clinicaltrials.gov Identifier
NCT06170242
Research summary
The purpose of this research is to test the effects of an experimental drug called EDP-323 (the ‘study drug’) that may be useful in treating patients infected with Respiratory Syncytial Virus (RSV-A Memphis 37b). RSV infection can cause a range of respiratory disease such as bronchitis and lower respiratory infections including bronchiolitis and pneumonia. These serious illnesses affect infants, certain adults who are older (especially if they are ≥65), have chronic heart or lung disease or have a weakened immune system. This study is funded by ENANTA Pharmaceuticals, Inc. and will take place in hVIVO facilities in London. To test the study drug, we infect healthy participants with a study virus in one of our Quarantine residential facilities. Up to 125 participants will take part in the study which will be split into two parts. Each participant will be in the study for about 4 months or 16 weeks from Screening to the last clinic visit.
The study will consist of 3 phases:
- Screening phase: Screening will occur between Day -90 to Day -2/-1. When historical screening data collected through the hVIVO generic screening process is used for screening, the study-specific ICF will be obtained at the first study-specific visit from each participant before any study-specific procedures are performed.
- Quarantine phase: Participants will stay in the quarantine unit for approximately 15 days. One to two days prior to the day of inoculation with RSV, participants will be admitted to quarantine where their eligibility will be reassessed before inoculation on Day 0. Participants will undergo a range of clinical assessments and safety monitoring for the entirety of their stay in quarantine. Participants will be discharged from the quarantine unit on from Day 12 (an extended stay may be required).
- Follow-up phase: Final follow-up visit 28 days (±3 days) after the day they receive the virus. Their symptoms will be reassessed, and a complete safety examination performed.Lay Summary of Results
"Short Summary:
Why was this study done? To look at the dose and possible side effects caused by EDP-323, a medicine that may be able to treat respiratory syncytial virus (RSV) infection. Researchers also wanted to see how much EDP-323 could lower levels of RSV during infection and reduce symptoms of RSV.
Who took part in the study? Healthy adults ages 18 to 47.
What did this study find? EDP-323 was well tolerated. It quickly lowered the levels of RSV and symptoms in healthy patients infected with RSV.What was studied and why?
A virus called respiratory syncytial virus (RSV) causes severe infection in the airways and lungs of young children and older adults. Researchers wanted to test a medicine called EDP-323 to find the dose that may best lower RSV levels, reduce symptoms, and look for possible side effects.Where and when was the study done?
The study started in November 2023 and finished in July 2024. It took place at a single site in the United Kingdom.Who took part in the study?
Healthy adult men and women ages 18 to 47 who volunteered to be infected with RSV in controlled conditions were in this study. Volunteers with active illness, taking certain medicines, having a recent vaccine, or with a history of smoking were not allowed to join.What kind of study was this?
Patients in the study were exposed to RSV in the clinic to start an infection and kept in quarantine in the clinic until their infection ended. They were checked daily for RSV infection and began treatment once an infection was detected or after 5 days had passed, whichever happened first.
In this study, some patients were given EDP-323 and others were given placebo, a capsule that looks like EDP-323 but does not have any EDP-323 medicine. It was important for some patients to not get any EDP-323 medicine so the researchers could make sure that it was EDP-323 that was working.
A computer program assigned each patient to receive either EDP-323 or placebo by chance, like flipping a coin. The patients and researchers did not know who received EDP-323 and who received placebo.How was the study done?
In this study, patients were split into 3 groups after infection with RSV:
• High Dose: patients received a daily high dose of EDP-323 for 5 days
• Low Dose: patients received a high dose of EDP-323 on the first day, followed by a lower dose for the next 4 days
• Patients received placebo for 5 days (for comparison)
A total of 142 patients were exposed to RSV to try to start an infection in the clinic. There were 47 patients in each group, and one patient in the placebo group did not finish the study.
Patients were checked daily for up to 5 days for RSV infection. When the lab detected an RSV infection, or after 5 days if no infection was detected, patients were placed in one of three groups and received either the High or Low dose EDP-323 treatment or placebo. Patients were also asked to report their symptoms starting on the day of RSV exposure.
Patients were followed by the clinic for about four weeks in total.What did this study find?
Patients in both EDP-323 groups had highly reduced levels of virus during RSV infection compared to the placebo group and also reported highly reduced symptoms of RSV compared to the placebo group. Both the Low Dose and High Dose groups showed similar success compared with each other.What were the side effects?
All medicines have side effects, but not every medicine will cause a side effect in everyone. It is important to work out which side effects are caused by the medicine, and which are caused by something else.
About one third of patients in each group reported side effects during the study. Most side effects were mild, were not caused by either the controlled infection or the EDP-323 treatments and were gone by the end of the study. There were no serious side effects and no deaths from RSV or other causes during the study.
The most common side effect possibly related to the lab-controlled RSV infection was headache. The most common side effect possibly related to EDP-323 was diarrhea, reported by two out of 94 patients.More details about this study?
• Where can I find more information about this study?
More information about this study can be found on the clinical trial database http://clinicaltrials.gov/ using the clinical trial number NCT06170242 or the ISRCTN Clinical Study Registry https://www.isrctn.com/ using the study number ISRCTN62572873.
• What is the technical study title?
A Randomized, Phase 2a, Double-Blind, Placebo-Controlled Study to Evaluate the Safety, Pharmacokinetics and Antiviral Activity of Multiple Doses of Orally Administered EDP-323 Against Respiratory Syncytial Virus Infection in the Virus Challenge Model in Healthy Adults.
• Who is responsible for this study?
This study was carried out and paid for by Enanta Pharmaceuticals, Inc.
Address: 4 Kingsbury Avenue, Watertown, MA 02472."REC name
London - Surrey Borders Research Ethics Committee
REC reference
23/LO/0636
Date of REC Opinion
12 Oct 2023
REC opinion
Further Information Favourable Opinion