zelicapavir (EDP-938) / Enanta Pharma - LARVOL DELTA

Zelicapavir demonstrates high clinical and functional barrier against antiviral resistance: results from a randomised double-blind placebo-controlled paediatric RSV antiviral clinical trial (ESCMID Global 2026) - No abstract available

Clinical • Pediatrics

Zelicapavir decreases symptom duration, hospitalisation and viral load in a global, randomised, double-blinded, placebo-controlled phase II trial of high-risk adults with RSV (ESCMID Global 2026) - No abstract available

Clinical • P2 data • Respiratory Syncytial Virus Infections

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 (clinicaltrials.gov) - P2 | N=150 | Not yet recruiting | Sponsor: Enanta Pharmaceuticals, Inc

New P2 trial • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Zelicapavir Reduces Symptom Duration and Hospitalization in a Randomized, Double-Blind, Placebo-Controlled, International, Phase 2 Trial (ATS 2026) - No abstract available

Clinical • P2 data

Respiratory syncytial virus in high-risk adults: A critical appraisal of therapeutic options and unmet needs. (PubMed, Respir Med) - "At present, ribavirin remains the only antiviral recommended for treatment in adults, and no mAb has received regulatory authorization for prophylaxis or therapy in this population...Nevertheless, newer drug candidates, including ziresovir, EDP-938, and S-337395, have shown encouraging antiviral activity and acceptable safety in adult studies. By examining both the scientific evidence and the structural factors shaping the current landscape, we emphasize the need for sustained adult-focused clinical development to complement preventive vaccination. Addressing this therapeutic gap will be essential to reduce the burden of RSV disease in high-risk adult populations, particularly as the global population ages."

Journal • Review • Infectious Disease • Pediatrics • Respiratory Diseases • Respiratory Syncytial Virus Infections

Zelicapavir (EDP-938) Antiviral Treatment is Associated with Shortened Duration of RSV Symptoms in a Randomized, Double-Blind, Placebo-Controlled, Clinical Trial in Children 28 Days to 36 Months of Age (IDWeek 2025) - No abstract available

Clinical • Infectious Disease

Zelicapavir (EDP-938) Antiviral Treatment is Associated with Shortened Duration of RSV Symptoms in a Randomized, Double-Blind, Placebo-Controlled, Clinical Trial in Children 28 Days to 36 Months of Age (IDWeek 2025) - No abstract available

Clinical • Infectious Disease

A Study to Investigate the Effects of Zelicapavir (EDP-938) on QTc Interval in Healthy Adults (clinicaltrials.gov) - P1 | N=72 | Completed | Sponsor: Enanta Pharmaceuticals, Inc | Recruiting ➔ Completed

Trial completion • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

RSVHR: A Study of EDP-938 in Non-hospitalized Adults With RSV Who Are at High Risk for Complications. (clinicaltrials.gov) - P2 | N=186 | Completed | Sponsor: Enanta Pharmaceuticals, Inc | Active, not recruiting ➔ Completed

Trial completion • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

RSVHR: A Study of EDP-938 in Non-hospitalized Adults With RSV Who Are at High Risk for Complications. (clinicaltrials.gov) - P2 | N=186 | Active, not recruiting | Sponsor: Enanta Pharmaceuticals, Inc | Recruiting ➔ Active, not recruiting

Enrollment closed • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

ANTIVIRAL TREATMENT OF RSV IN CHILDREN: VIROLOGY AND PK RESULTS OF A RANDOMIZED DOUBLE-BLIND PLACEBO-CONTROLLED INTERNATIONAL TRIAL OF ZELICAPAVIR (EDP-938) (ESPID 2025) - P2 | "None led to treatment discontinuation or study withdrawal. Conclusions/Learning Points Zelicapavir achieved target exposures, was well-tolerated, and produced large magnitude VL declines in this first-in-pediatrics trial, thus supporting further pediatric development."

Clinical • Infectious Disease • Respiratory Syncytial Virus Infections

Enanta Pharmaceuticals to Present Data for its Respiratory Syncytial Virus Program at the 13th International RSV Symposium (Businesswire) - "Enanta Pharmaceuticals, Inc...today announced that an oral presentation and three posters, including one late breaker, highlighting the company’s respiratory syncytial virus (RSV) program, will be presented at the 13th International RSV Symposium (RSV 2025) being held March 12-15 at Bourbon Cataratas do Iguazu, in Iguazu Falls, Brazil. Results from a Phase 2 human challenge study of EDP-323, an RSV L-protein inhibitor...will be highlighted in an oral presentation. Data from a Phase 2 study of zelicapavir, an N-protein inhibitor, for the treatment of RSV in young children will be presented in a late breaker poster. An additional poster will highlight distinctions among fusion, N, and L inhibitors with respect to preclinical antiviral effect and resistance profiles, while a third poster will detail PK and PK/PD results from the EDP-323 Phase 2 human challenge study."

Clinical data • Preclinical • Infectious Disease • Respiratory Syncytial Virus Infections

Enanta Pharmaceuticals Reports Financial Results for its Fiscal First Quarter Ended December 31, 2024 (Businesswire) - "Zelicapavir is being evaluated in RSVHR, a Phase 2b, randomized, double-blind, placebo-controlled study in adults with RSV infection who are at high risk of complications, including age over 65 years and/or those with congestive heart failure, chronic obstructive pulmonary disease or asthma. Enrollment in RSVHR is progressing, and the company is targeting completion in the current Northern Hemisphere RSV season with topline data in the third quarter of 2025."

P2b data • Respiratory Syncytial Virus Infections

EDP-938 Has a High Barrier to Resistance in Healthy Adults Experimentally Infected with Respiratory Syncytial Virus. (PubMed, J Infect Dis) - P2a | "In human RSV infections treated with EDP-938, emergence of RSV variants with reduced sensitivity to EDP-938 occurred in only 1 participant and was associated with reduced viral fitness. EDP-938's high barrier to resistance highlights its robust mechanism of action."

Journal • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

RSVHR: A Study of EDP-938 in Non-hospitalized Adults With RSV Who Are at High Risk for Complications. (clinicaltrials.gov) - P2 | N=180 | Recruiting | Sponsor: Enanta Pharmaceuticals, Inc | Phase classification: P2b ➔ P2 | Trial completion date: Apr 2024 ➔ Apr 2025 | Trial primary completion date: Apr 2024 ➔ Apr 2025

Phase classification • Trial completion date • Trial primary completion date • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

RSVPEDs: A Study to Evaluate EDP 938 Regimens in Children With RSV (clinicaltrials.gov) - P2 | N=96 | Completed | Sponsor: Enanta Pharmaceuticals, Inc | Recruiting ➔ Completed | Trial completion date: Apr 2024 ➔ Aug 2024 | Trial primary completion date: Apr 2024 ➔ Aug 2024

Trial completion • Trial completion date • Trial primary completion date • Respiratory Diseases • Respiratory Syncytial Virus Infections

A Study to Investigate the Effects of Zelicapavir (EDP-938) on QTc Interval in Healthy Adults (clinicaltrials.gov) - P1 | N=72 | Recruiting | Sponsor: Enanta Pharmaceuticals, Inc

New P1 trial • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Systematic Review of the Efficacy and Safety of RSV-Specific Monoclonal Antibodies and Antivirals in Development. (PubMed, Rev Med Virol) - "Results from 59 studies were extracted, covering efficacy and safety data on six mAbs (motavizumab, motavizumab-YTE, nirsevimab, ALX-0171, suptavumab, clesrovimab) and 12 AV therapies (ALN-RSV01, RSV604, presatovir, MDT-637, lumicitabine, IFN-α1b, rilematovir, enzaplatovir, AK0529, sisunatovir, PC786, EDP-938). Moving forward, passive immunisation and treatment options for RSV infection will play a significant role in reducing the health burden of RSV, complementing recent advancements in vaccine development. TRIAL REGISTRATION: PROSPERO registration: CRD42022376633."

Journal • Review • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections • IFNA1

RSVTx: Effects of EDP-938 in Hematopoietic Cell Transplant Recipients Who Are Infected With Acute Respiratory Syncytial Virus (RSV) of the Upper Respiratory Tract (clinicaltrials.gov) - P2 | N=9 | Terminated | Sponsor: Enanta Pharmaceuticals, Inc | Phase classification: P2b ➔ P2 | N=200 ➔ 9 | Trial completion date: Apr 2024 ➔ Jun 2023 | Recruiting ➔ Terminated | Trial primary completion date: Apr 2024 ➔ Jun 2023; Study was terminated due to a strategic business decision and not due to safety concerns.

Enrollment change • Phase classification • Trial completion date • Trial primary completion date • Trial termination • Bone Marrow Transplantation • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections • Transplantation

RSVPEDs: A Study to Evaluate EDP 938 Regimens in Children With RSV (clinicaltrials.gov) - P2 | N=90 | Recruiting | Sponsor: Enanta Pharmaceuticals, Inc | Trial completion date: Dec 2023 ➔ Apr 2024 | Trial primary completion date: Dec 2023 ➔ Apr 2024

Trial completion date • Trial primary completion date • Respiratory Diseases • Respiratory Syncytial Virus Infections

EDP-938, A Respiratory Syncytial Virus (RSV) antiviral, demonstrates a high barrier to resistance in a human challenge study (IDWeek 2023) - No abstract available

Infectious Disease

A study to learn how well the drug EDP 938 works and how safe it is for non hospitalized Adults with Acute Respiratory Syncytial Virus Infection, who are at High Risk for Complications (clinicaltrialsregister.eu) - P2 | N=180 | Ongoing | Sponsor: Enanta Pharmaceuticals, Inc.

New P2 trial • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Immunity Cell Responses to RSV and the Role of Antiviral Inhibitors: A Systematic Review. (PubMed, Infect Drug Resist) - "EDP-938 inhibits viral nucleoprotein (N), while GRP-156784 blocks the activity of respiratory syncytial virus ribonucleic acid (RNA) polymerase. PC786 inhibits non-structural protein 1 (NS-1) gene, RANTES transcripts, virus-induced CCL5, IL-6, and mucin increase...Many respiratory syncytial virus inhibitors are proposed; however, only palivizumab and ribavirin are approved for prophylaxis and treatment, respectively. Hence, this review is focused on immunity cell responses to respiratory syncytial virus and the role of antiviral inhibitors."

Journal • Review • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections • CCL11 • CCL3 • CD8 • CXCL10 • GZMA • IFNA1 • IFNB1 • IFNG • IL13 • IL1B • IL2 • IL4 • IL6 • TNFA

EDP-938, a new antiviral with inhibitory activity against the nucleoprotein of the respiratory syncytial virus. (PubMed, Rev Esp Quimioter) - "EDP-938 has shown high efficacy against RSV. The first trials in humans have shown that this antiviral is rapidly absorbed after oral administration and has a half-life of between 11-18 hours Administration for seven days of multiple oral doses of up to 600 mg/day or 300 mg/day/twice a day, there were hardly any significant adverse effects and the viral load in the lower respiratory tract decreased significantly."

Journal • Review • Respiratory Diseases • Respiratory Syncytial Virus Infections

RSVHR: A Study of EDP-938 in Non-hospitalized Adults With RSV Who Are at High Risk for Complications. (clinicaltrials.gov) - P2b | N=180 | Recruiting | Sponsor: Enanta Pharmaceuticals, Inc

New P2b trial • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections