A Controlled Phase 2a Study to Evaluate the Efficacy of EDP-323 Against Respiratory Syncytial Virus Infection in a Virus Challenge Model

NCT06170242 | Completed Phase 2 Results FDA Drug

• 1 other identifier: EDP 323-101
• Study Type: interventional
• Target: 142
• Locations: 1 country
• Sites: 1

Brief Summary

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 in healthy subjects infected with RSV-A Memphis 37b. This study is designed to assess the antiviral effect of EDP-323 compared to a placebo control in the respiratory syncytial virus challenge model.

Conditions

RSV Infection

Keywords

challenge study; RSV; antiviral; RSV-A Memphis 37b

Outcome Measures

Primary Outcomes (1)

• Quantitative Reverse Transcription-polymerase Chain Reaction (qRT-PCR): RSV Area Under the Viral Load-time Curve (VL-AUC)

  Measured by qRT-PCR in nasal samples.

  Day 1 to Day 12

Secondary Outcomes (29)

• qRT-PCR: RSV Peak Viral Load (VLPEAK)

  Day 1 to Day 12

• qRT-PCR: Time From the Assessment at the Time of the First Dose of IMP to RSV VLPEAK

  Day 1 to Day 12

• qRT-PCR: Time From the Assessment at the Time of the First Dose of IMP to RSV Viral Load Negativity

  Day 1 to Day 12

• qRT-PCR: Time From the Assessment at the Time of the First Dose of IMP to First Negative Slope of RSV Viral Load

  Day 1 to Day 12

• qRT-PCR: RSV Viral Load Clearance Rate - EDP-323 High Dose

  Up to Day 16

Study Arms (3)

EDP-323 Arm A

EXPERIMENTAL

Subjects will take EDP-323 Dose 1 orally for 5 days

Drug: EDP-323 Dose Regimen 1

EDP-323 Arm B

EXPERIMENTAL

Subjects will take EDP-323 Dose 2 orally for 5 days

Drug: EDP-323 Dose Regimen 2

Placebo Arm C

PLACEBO COMPARATOR

Subjects will take matching placebo orally for 5 days

Drug: Placebo

Interventions

EDP-323 Dose Regimen 1 DRUG

EDP-323 capsule

EDP-323 Arm A

EDP-323 Dose Regimen 2 DRUG

EDP-323 capsule

EDP-323 Arm B

Placebo DRUG

Placebo capsule

Placebo Arm C

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• An informed consent document signed and dated by the subject.
• Age 18 to 55 years, inclusive.
• In good health with no history of major medical conditions.
• A total body weight ≥ 50 kg and Body Mass Index (BMI) ≥ 18 kg/m2 and ≤ 35kg/m2.

You may not qualify if:

• Pregnant or nursing females
• Acute or chronic medical illness
• History of, or currently active, symptoms or signs suggestive of upper or lower respiratory tract (URT or LRT) infection within 4 weeks prior to the first study visit.
• Abnormal lung function
• Positive for HIV, active hepatitis B or C test
• Nose or nasopharynx abnormalities
• Receipt of any investigational drug within 3 months prior to the planned date of viral challenge/first dose of study drug

Sponsors & Collaborators

• Enanta Pharmaceuticals, Inc: lead
• hVIVO Services Limited: collaborator

Study Sites (1)

hVIVO Services Limited

London, United Kingdom

Location

MeSH Terms

Conditions

Respiratory Syncytial Virus Infections

Condition Hierarchy (Ancestors)

Pneumovirus Infections; Paramyxoviridae Infections; Mononegavirales Infections; RNA Virus Infections; Virus Diseases; Infections

Results Point of Contact

• Title: Medical Monitor
• Organization: Enanta Pharmaceuticals, Inc.

enquiries@enanta.com

+1 6176070800

Study Officials

• Enanta Pharmaceuticals, Inc

  Enanta Pharmaceuticals, Inc

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 27, 2023
• First Posted: December 14, 2023
• Study Start: November 20, 2023
• Primary Completion: June 17, 2024
• Study Completion: July 12, 2024
• Last Updated: October 7, 2025
• Results First Posted: October 7, 2025

Record last verified: 2025-09

Locations

GB (1)