A Phase 2 Study to Investigate the Efficacy and Safety of Zelicapavir in Participants Aged ≥28 Days to ≤36 Months of Age Infected With Respiratory Syncytial Virus

NCT07482657 | Not Yet Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: EDP 938-203
• Study Type: interventional
• Target: 150
• Locations: 0 countries
• Sites: N/A

Brief Summary

Zelicapavir is a novel, orally administered, nonfusion replication inhibitor of RSV. It is being investigated in this Phase 2 study (EDP 938-203) as a potential treatment for RSV infection in both hospitalized and non-hospitalized children aged ≥28 days to ≤36 months who present with symptomatic RSV infection.

Conditions

RSV Infection; RSV; Respiratory Syncytial Virus (RSV)

Keywords

RSV; children; Respiratory Syncytial Virus; Pediatric study

Outcome Measures

Primary Outcomes (1)

• Time to complete resolution of clinical signs of RSV as measured by RESOLVE-P

  Day 1 through Day 14

Secondary Outcomes (10)

• Time to sustained resolution of clinical signs of RSV as measured by RESOLVE-P

  Day 1 through Day 14

• Change in severity of clinical signs of RSV from Baseline to D7 as measured by RESOLVE-P

  Day 1 through Day 7

• Proportion of participants with Lower Respiratory Tract Infection (LRTI)

  D1 through D14

• Change in severity of RSV from Baseline to D7 and D14

  Baseline to D7 and D14

• Proportion of outpatient participants who were hospitalized due to RSV or other causes during the study period

  Day 1 through Day 35

Study Arms (2)

zelicapavir

EXPERIMENTAL

zelicapavir, oral suspension, once daily for 7 days

Drug: zelicapavir

Placebo

PLACEBO COMPARATOR

Matching placebo, orally, once daily for 7 days

Drug: Placebo

Interventions

zelicapavir DRUG

Oral suspension

zelicapavir

Placebo DRUG

Placebo oral suspension to match zelicapavir

Placebo

Eligibility Criteria

• Age: 28 Days - 36 Months
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Participants diagnosed with RSV infection using an approved diagnostic assay, without known and/or documented coinfection with SARS-CoV-2 or influenza
• Participant has signs of RSV infection with onset ≤3 days (72 hours) at the time of randomization
• In the Investigator's opinion, the participant's caregiver understands and is able to comply with protocol requirements, instructions, and restrictions, and the participant is likely to complete the study as planned. The caregiver(s) should be of legal age.

You may not qualify if:

• Participant has any condition that in the opinion of the Investigator would interfere with the evaluation of the study drug or participant safety.
• Participant has underlying immune deficiency. Participants with immunoglobulin A deficiency are not excluded.
• Participant has had major surgery within 6 weeks prior to randomization or has major surgery planned during the course of the study.
• Participant is currently taking either chronically or has taken within 7 days prior to randomization, or is anticipated to receive during the course of the study, systemic medications that are known to cause immunosuppression other than corticosteroids for \>5 days.
• Participant has received an investigational agent within the last 30 days or 5 half-lives of the investigational agent, whichever is longer.

Sponsors & Collaborators

• Enanta Pharmaceuticals, Inc: lead

MeSH Terms

Conditions

Respiratory Syncytial Virus Infections

Condition Hierarchy (Ancestors)

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

Study Officials

• Enanta Pharmaceuticals, Inc

  Enanta Pharmaceuticals, Inc

  STUDY DIRECTOR

Central Study Contacts

Enanta Pharmaceuticals, Inc

CONTACT

617 607-0800; charris@enanta.com

Study Design

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

Study Record Dates

• First Submitted: March 16, 2026
• First Posted: March 19, 2026
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: March 19, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share