A Study of EDP-938 in Non-hospitalized Adults With RSV Who Are at High Risk for Complications. (RSVHR)

A Phase 2b, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of EDP-938 in Non-hospitalized Adults With Acute Respiratory Syncytial Virus Infection Who Are at High Risk for Complications

This was a Phase 2b, randomized, double-blind, placebo-controlled study of EDP-938 administered orally for the treatment of non-hospitalized adult subjects with confirmed RSV infection who were at high risk for complications after RSV infection.

Study Overview

• Status: Completed
• Conditions: RSV Infection
• Intervention / Treatment: Drug: EDP-938; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 187
• Phase: Phase 2

Contacts and Locations

Study Locations

• Argentina
  • Buenos Aires
    • La Plata, Buenos Aires, Argentina, 1900
      • Instituto Medico Platense
    • Mar del Plata, Buenos Aires, Argentina, B7600FYK
      • Centro de Investigaciones Medica Mar del Plata
    • Munro, Buenos Aires, Argentina, B1605
      • Clinica Privada Independencia
  • Ciudad Autónoma de BuenosAires
    • Buenos Aires, Ciudad Autónoma de BuenosAires, Argentina, C1426ABP
      • Consultorios Médicos Dr. Doreski
  • Córdoba Province
    • Río Cuarto, Córdoba Province, Argentina, 5800
      • Instituto Médico Río Cuarto
  • Santa Fe Province
    • Santa Fe, Santa Fe Province, Argentina, 3000
      • Instituto Del Buen Aire
  • Tucumán Province
    • San Miguel de Tucumán, Tucumán Province, Argentina, T4000NWB
      • Clínica Mayo de U.M.C.B. S.R.L
• Bulgaria
  • Haskovo, Bulgaria, 6305
    • Specialized Hospital for Active Treatment of Pneumophthisiatric Diseases - Haskovo EOOD
  • Veliko Tarnovo, Bulgaria, 5006
    • Medical Center Neuromedix EOOD
  • Blagoevgrad
    • Blagoevgrad, Blagoevgrad, Bulgaria, 2700
      • Multiprofile Hospital for Active Treatment Puls AD - PPDS
  • Burgas
    • Burgas, Burgas, Bulgaria, 8000
      • Medical Center For Life EOOD
  • Gabrovo
    • Sevlievo, Gabrovo, Bulgaria, 5400
      • Diagnostic Consultative Center-1-Sevlievo EOOD
  • Kozloduy
    • Kozloduy, Kozloduy, Bulgaria, 3320
      • Medical Center Zdrave-1 OOD
  • Kyustendil
    • Kyustendil, Kyustendil, Bulgaria, 2500
      • Medical Center Hera - Kyustendil EOOD
  • Lovech
    • Troyan Municipality, Lovech, Bulgaria, 5600
      • Specialized Hospital for Active Treatment of Pulmonary Diseases
  • Montana
    • Lom, Montana, Bulgaria, 3600
      • Diagnostic Consultative Center 1- Lom EOOD
    • Montana, Montana, Bulgaria, 3400
      • Medical Center Hera EOOD, Montana
  • Pernik
    • Pernik, Pernik, Bulgaria, 2300
      • Specialized Hospital for Active Treatment of Pulmonary Diseases- Pernik EOOD
  • Ruse
    • Rousse, Ruse, Bulgaria, 7002
      • Medical Center Prolet EOOD
  • Sevlievo
    • Sevlievo, Sevlievo, Bulgaria, 5400
      • Medical Center Hipocrena
  • Sofia
    • Sofia, Sofia, Bulgaria, 1202
      • Medical Center Hera EOOD
    • Sofia, Sofia, Bulgaria, 1750
      • University Multiprofile Hospital for Active Treatment Sofiamed OOD
  • Sofia-Grad
    • Sofia, Sofia-Grad, Bulgaria, 1431
      • Medical Center Sanador M EOOD
  • Varna
    • Varna, Varna, Bulgaria
      • Medical Centre Pratia Clinic EOOD Varna
  • Veliko Tarnovo
    • Veliko Tarnovo, Veliko Tarnovo, Bulgaria, 5000
      • Medical Center Tara OOD
• Colombia
  • Barranquilla, Colombia, 080020
    • Oinsamed S.A.S - Clinica Misericordia
  • Medellín, Colombia, 050021
    • Fundacion Centro de Investigacion Clinica CIC
  • Antioquia
    • Medellín, Antioquia, Colombia, 50021
      • Servicios de Salud IPS Suramericana S.A.S. - IPS Sura Industriales Medellin
  • Atlántico
    • Barranquilla, Atlántico, Colombia, 080020
      • Clinica de la Costa Ltda - PPDS
  • Cundinamarca
    • Chía, Cundinamarca, Colombia, 250001
      • Clínica Universidad De la Sabana
  • Risaralda Department
    • Pereira, Risaralda Department, Colombia, 660003
      • Fundación Centro De Investigaciones Clinicas Ips Cardiomet Pereira
• Czechia
  • Nový Knín, Czechia, 262 03
    • Res Medica s.r.o.
  • Liberec Region
    • Liberec, Liberec Region, Czechia, 460 14
      • MUDr. Jakub Strincl, s.r.o.
• Malaysia
  • Sarawak
    • Miri, Sarawak, Malaysia, 98000
      • Hospital Miri
• Mexico
  • Oaxaca City, Mexico, 68000
    • Oaxaca Site Management Organization - Clinic - OSMO - PPDS
  • Jalisco
    • Guadalajara, Jalisco, Mexico, 44160
      • CICUM San Miguel
    • Guadalajara, Jalisco, Mexico, 44100
      • Instituto Jalisciense de Investigación Clínica Sa de Cv
    • Guadalajara, Jalisco, Mexico, 44690
      • Centro de Investigación Clinica Médica y Farmacoló
    • Guadalajara, Jalisco, Mexico, 45235
      • Hospital Civil Fray Antonio Alcalde
  • Mexico City
    • Mexico City, Mexico City, Mexico, 06760
      • Centro de Atención e Investigación Médica S.A. - México - CAIMED - PPDS
  • Nuevo León
    • Monterrey, Nuevo León, Mexico, 31000
      • Accelerium, S. de R.L. de C.V. - PPDS
    • Monterrey, Nuevo León, Mexico
      • Camacho Ortiz, Adrian
  • Veracruz
    • Veracruz, Veracruz, Mexico, 91020
      • Centro de Alta Especialidad Dr. Rafael Lucio
    • Veracruz, Veracruz, Mexico, 91700
      • FAICIC
• Poland
  • Łódź Voivodeship
    • Lodz, Łódź Voivodeship, Poland, 91-463
      • Centrum Medyczne PROFAMILIA
• Slovakia
  • Spišská Nová Ves, Slovakia, 052 01
    • Plucna ambulancia Hrebenar, s.r.o.
• South Africa
  • Johannesburg, South Africa, 2001
    • Newtown Clinical Research Centre
  • Paarl, South Africa, 7646
    • Be Part Yoluntu Centre
• Spain
  • Santiago de Compostela, Spain, 15706
    • CHUS - H. Clinico U. de Santiago
  • Alicante
    • Alicante, Alicante, Spain, 03010
      • Hospital General Universitario Dr. Balmis
  • Cordoba
    • Cabra, Cordoba, Spain, 14940
      • Centro de salud Cabra Matrona Antonia Mesa Fernández
• Taiwan
  • Taichung, Taiwan, 40705
    • Taichung Veterans General Hospital
  • Taipei, Taiwan, 11490
    • Tri-Service General Hospital
• United States
  • Arizona
    • Tempe, Arizona, United States, 85282-2455
      • Voyage Medical
  • California
    • Fresno, California, United States, 93701
      • UCSF Fresno
    • Lomita, California, United States, 90717
      • Torrance Clinical Research Institute
    • Los Angeles, California, United States, 90017
      • Downtown LA Research Center Inc - ClinEdge - PPDS
    • Westminster, California, United States, 92683
      • Allianz Research Institute Inc
  • Colorado
    • Aurora, Colorado, United States, 80014
      • Allianz Research Institute - Colorado
  • Florida
    • Bay Pines, Florida, United States, 33744
      • Bay Pines VA Healthcare System
    • Cape Coral, Florida, United States, 33990
      • C&A Clinical Trials Corp
    • Cutler Bay, Florida, United States, 33157
      • Beautiful Minds Clinical Research Center
    • Hialeah, Florida, United States, 33015
      • Dinamo Research & Diagnostic center, LLC
    • Kissimmee, Florida, United States, 34741
      • I.H.S Health LLC
    • Miami, Florida, United States, 33144
      • Dynamic Medical Research, LLC
    • Miami, Florida, United States, 33179-2537
      • Floridian Research Institute
    • Orlando, Florida, United States, 32827
      • Orlando VA Healthcare System
    • Ormond Beach, Florida, United States, 32174
      • Ormond Beach Clinical Research
    • Port Saint Lucie, Florida, United States, 34952
      • CDC Research Institute, LLC
    • Tampa, Florida, United States, 33615
      • Santos Research Center
    • Tampa, Florida, United States, 33607
      • Research Bay, Inc.
  • Georgia
    • East Point, Georgia, United States, 30344
      • Covenant Pulmonary Criticial Care and Research Ins
  • Idaho
    • Idaho Falls, Idaho, United States, 83404
      • Snake River Research
  • Kentucky
    • Louisville, Kentucky, United States, 40202
      • University of Louisville
  • Montana
    • Butte, Montana, United States, 59701
      • Mercury Street Medical
  • New York
    • Syracuse, New York, United States, 13210-1685
      • Global Health Institute
  • North Carolina
    • Winston-Salem, North Carolina, United States, 27103
      • Progressive Medicine of the Triad, LLC
  • Ohio
    • Toledo, Ohio, United States, 43617
      • Toledo Institute of Clinical Research
  • Texas
    • Austin, Texas, United States, 78704-7507
      • IMA Clinical Research - Austin - PPDS
    • Fort Worth, Texas, United States, 76164-9041
      • Valley Institute of Research
    • Houston, Texas, United States, 77022
      • HDH Research, Inc.
    • McKinney, Texas, United States, 75069
      • Metroplex Pulmonary and Sleep Medicine Center-4833 Medical Center Dr Unit 6B
    • Mesquite, Texas, United States, 75149
      • SMS Clinical Research, LLC
  • Washington
    • Redmond, Washington, United States, 98052
      • Eastside Research Associates

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• At least one of the following conditions that predispose them to complications after RSV infection:

  1. Age ≥65 years
  2. Congestive heart failure (CHF)
  3. Asthma
  4. Chronic obstructive pulmonary disease (COPD)
• The subject has a new onset of any of the following symptom(s) or worsening of pre-existing symptom(s) consistent with a respiratory tract infection no more than 72 hours prior to the administration of the first dose of study drug: feeling feverish, headache, neck pain, fatigue, loss of appetite, interrupted sleep, body aches, sore throat, nasal congestion, cough, cough with phlegm, wheezing, or short of breath.
• The subject reports at least 2 of the following symptoms, one of which must be reported as at least 'moderate' severity: cough, cough with phlegm, wheezing, or short of breath
• The subject has tested positive for RSV infection using a NAAT (polymerase chain reaction [PCR] or other) on a nasal/nasopharyngeal swab sample.
• A woman of childbearing potential who is sexually active with a male must agree to use two effective methods of contraception from the date of Screening until 30 days after her last dose of study drug.
• A male subject who has not had a vasectomy and is sexually active with a woman of childbearing potential must agree to use effective contraception from the date of Screening to 90 days after his last dose of study drug.

Exclusion Criteria:

• The subject has an anticipated need for hospitalization within 24 hours of signing the Study ICF
• The subject has concomitant respiratory infections that are viral (other than RSV but including influenza), bacterial, or fungal, including systemic bacterial or fungal infections, within 7 days prior to signing the Study ICF
• The subject has a SARS-CoV-2 test result that is positive within 28 days prior to signing the Study ICF
• The subject has COPD with spirometry results (obtained within 1 year prior to signing the Study ICF) FEV1 ≤35%
• The subject has a known positive human immunodeficiency virus infection, active hepatitis A virus infection, chronic hepatitis B virus infection, and/or current hepatitis C virus (HCV) infection; subjects with a history of HCV infection who have achieved a documented sustained virologic response 12 weeks after completion of HCV therapy may be enrolled.
• The subject has any of the following cardiac conditions: any congenital heart disease, congenital long QT syndrome, or any clinical manifestation resulting in QT interval prolongation
• The subject has immunocompromised status
• The subject is living in institutional care or assisted living facility and is also receiving acute care management for any respiratory condition; Note: Independent living apartments are not considered institutional care or assisted living facility

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: EDP-938; EDP-938 800 mg, once daily	Drug: EDP-938; Subjects took EDP-938 once daily for 5 days
Placebo Comparator: Placebo; Matching placebo, once daily	Drug: Placebo; Subjects took matching placebo, once daily for 5 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Resolution of RSV Lower Respiratory Tract Disease (LRTD) Symptoms	Resolution of LRTD Symptoms is defined as the first of two consecutive timepoints where each of the four LRTD symptoms (cough, short of breath, wheezing and coughing up phlegm[sputum]) as assessed by RiiQTM Scale Score is zero or 1. Time to resolution of LRTD symptoms is calculated as: date/time of resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Time to Complete Resolution of LRTD Symptoms for the mITT Population	Complete resolution of LRTD Symptoms is defined as the first of two consecutive timepoints where each of the four LRTD symptoms (cough, short of breath, wheezing and coughing up phlegm[sputum]) as assessed by Respiratory Infection Intensity and Impact Questionnaire (RiiQ) Scale Score is zero. Time to complete resolution of LRTD symptoms is calculated as: date/time of complete resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Time to Complete Resolution of LRTD Symptoms for the HR3 Population	Complete resolution of LRTD Symptoms is defined as the first of two consecutive timepoints where each of the four LRTD symptoms (cough, short of breath, wheezing and coughing up phlegm[sputum]) as assessed by RiiQTM Scale Score is zero. Time to complete resolution of LRTD symptoms is calculated as: date/time of complete resolution - date/time of first dose with conversion to days.	Day 1 through Day 33

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma PK Concentrations of EDP-938		Up to Day 5
Time to Resolution of LRTD Symptoms and 2 Systemic Symptoms	Resolution of LRTD and 2 Systemic Symptoms is defined as the first of two consecutive timepoints where each of the four LRTD symptoms (cough, short of breath, wheezing and coughing up phlegm[sputum]) and each of the 2 systemic symptoms (feeling fever and fatigue/tiredness) as assessed by Respiratory Infection Intensity and Impact Questionnaire (RiiQ) Scale Score is zero or 1; Higher scores indicate worse outcomes (greater symptom intensity and greater impact on daily functioning). Time to resolution is calculated as: date/time of resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Time to Resolution of All RSV Symptoms	Resolution of all RSV Symptoms is defined as the first of two consecutive timepoints where each of the 13 RSV symptoms as assessed by RiiQ Scale Score is zero or 1. Time to resolution is calculated as: date/time of resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Time to Complete Resolution of All RSV Symptoms for the mITT Population	Complete resolution of all RSV Symptoms is defined as the first of two consecutive timepoints where each of the 13 RSV symptoms as assessed by RiiQTM Scale Score is zero. Time to complete resolution is calculated as: date/time of complete resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Time to Complete Resolution of All RSV Symptoms for the HR3 Population	Complete resolution of all RSV Symptoms is defined as the first of two consecutive timepoints where each of the 13 RSV symptoms as assessed by RiiQTM Scale Score is zero. Time to complete resolution is calculated as: date/time of complete resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Change From Baseline in Severity of RSV LRTD Symptoms	The RiiQ Infection Intensity Scale assesses 4 symptoms of LRTD (cough, shortness of breath, wheezing, and expectoration) on a scale from 0 (absent) to 3 (severe). The composite LRTD Score is the average of all 4 individual item scores.	Day 1 through Day 33
Change From Baseline for Impact Scale	The RiiQ Impact Scale assesses daily activities (7 items), emotions (4 items), and social relationships (5 items) on a scale of 0 (no impact) to 3 (extreme impact). The composite Impact Score is the average of all 16 individual item scores.	Day 1 through Day 33
Time to Resolution of Upper Respiratory Tract Disease Congestion, LRTD, and 2 Systemic Symptoms	Resolution of Symptoms is defined as the first of two consecutive timepoints where each of the RSV symptoms (4 LRTD symptoms [cough, short of breath, wheezing, coughing up phlegm [sputum]], 2 URTD symptoms [nasal congestion and sore throat], 2 Systemic symptoms [feeling feverish and fatigue[tiredness]]) as assessed by RiiQTM Scale Score is zero or 1. Time to resolution is calculated as: date/time of resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Time to no or Mild Impact of RSV Disease on Daily Activities, Emotions, and Social Relationships	Resolution of No or Mild Impact of RSV is defined as the first of two consecutive timepoints where each of the 3 impact Scale Scores (daily activities, emotions and social relationships) as assessed by RiiQTM Scale Score is zero or 1. Time to resolution is calculated as: date/time of resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Percentage of Participants With Post-baseline RSV-related Complications		Day 1 through Day 33
Time to Improvement in RSV Disease	Time to Improvement is defined as the time from first dose to first timepoint where the response assessed by PGI-C is 'Much better'. Time to Improvement is calculated as: date/time of Improvement - date/time of first timepoint.	Day 1 through Day 33
Change From Baseline for Health-Related Quality of Life	Assessed by EuroQol 5 Dimensions 5 Levels (EQ-5D-5L) questionnaire; 5 dimensions (mobility, taking care of yourself, usual activities, pain/discomfort, and anxiety/depression) are scored on 5 levels from 1 (full health) to 5 (extreme disability). An index score is derived based on the 5 reported levels where 1.0 represents full health and 0.0 the worst possible health.	Day 1 through Day 33
Time to Return to Usual Health	Time to return to usual health is defined as the time from first dose to first timepoint where the response as assessed by Adult Return to Usual Health is 'Yes'. Time to return to usual health is calculated as: date/time of return to usual health - date/time of response to 'Yes'.	Day 1 through Day 33
Time to Return to Usual Activities	Time to return to usual activities is defined as the time from first dose to first timepoint where the response as assessed by Adult Return to Usual Activities is 'Yes'. Time to return to usual activities is calculated as: date/time of return to usual activities - date/time of first response to 'Yes'.	Day 1 through Day 33
Percentage of Subjects Requiring Hospitalization for RSV or Other Causes		Day 1 through Day 33
Duration of Hospitalization for RSV or Other Causes		Day 1 through Day 33
All-cause Mortality		Day 1 through Day 33
RSV RNA Viral Load Change From Baseline for the mITT Population		Days 3, 5, 9, and 14
Change in Infectious RSV Viral Load Over Time		Up to Day 14
Proportion of Subjects With RSV RNA Viral Load Target Not Detected (TND) for the mITT Population		Days 1, 3, 5, 9 and 14
Time to RSV RNA Viral Load TND for the mITT Population	Time to RSV viral load TND is defined as the time between the date of first dose to the first date of achieving viral load TND.	Day 1 through Day 14
Safety as Measured by Frequency of Adverse Events (AEs)	Number of subjects experiencing any Treatment-Emergent Adverse Events (TEAEs)	Up to Day 33
Time to Resolution of RSV Infection Symptoms by Patient Global Impression of Severity (PGI-S) Scale Score for the mITT Population	PGI-S is a 7-point patient-reported scale ranging from 1 (normal/none) to 7 (among the most extremely ill); lower scores indicate less severe disease. Time to resolution is defined as time from the first dose to first of two consecutive timepoints where the response assessed by PGI-S is 'None'. Time to resolution is calculated as: date/time of resolution - date/time of first dose with conversion to days.	Day 1 through Day 33
Incidence of New Antibiotic Use, or New or Increased Use of Bronchodilators, Systemic or Inhaled Corticosteroids, or Oxygen Supplementation for the mITT Population	Incidence was defined as the number of subjects with new antibiotic, bronchodilators, inhaled corticosteroids or oxygen use	Day 1 through Day 33
Incidence of Unscheduled Medically Attended Visits for RSV Infection or Other Causes for the mITT Population	Incidence was defined as the number of subjects with unscheduled medically attended visits for RSV infection or other causes.	Day 1 through Day 33

Collaborators and Investigators

• Sponsor: Enanta Pharmaceuticals, Inc
• Investigators: Study Director: Enanta Pharmaceuticals, Inc, Enanta Pharmaceuticals, Inc

Study record dates

Study Major Dates

• Study Start (Actual): November 29, 2022
• Primary Completion (Actual): June 23, 2025
• Study Completion (Actual): June 23, 2025

Study Registration Dates

• First Submitted: October 3, 2022
• First Submitted That Met QC Criteria: October 3, 2022
• First Posted (Actual): October 6, 2022

Study Record Updates

• Last Update Posted (Actual): August 19, 2026
• Last Update Submitted That Met QC Criteria: July 28, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: High Risk, Respiratory Syncytial Virus
• Additional Relevant MeSH Terms: Infections; RNA Virus Infections; Virus Diseases; Pneumovirus Infections; Paramyxoviridae Infections; Mononegavirales Infections; Respiratory Syncytial Virus Infections; EDP-938
• Other Study ID Numbers: EDP 938-104

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No