Phase 1, Randomized, Double-Blind Four-Period Crossover, Thorough QT/QTc Study to Evaluate the Effects of EDP-938 on Cardiac Repolarization in Healthy Adults

The purpose of the study is to assess the effect of a therapeutic and supratherapeutic dose of zelicapavir on the corrected cardiac QT interval relative to a placebo and positive control in healthy participants.

Start Date15 Jul 2024

Sponsor / Collaborator

Enanta Pharmaceuticals, Inc.

NCT04816721

/ CompletedPhase 2

A PHASE 2, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, 2-PART STUDY TO EVALUATE EDP-938 REGIMENS IN SUBJECTS AGED 28 DAYS TO 36 MONTHS INFECTED WITH RESPIRATORY SYNCYTIAL VIRUS (RSV)

A 2-part study to evaluate the safety, pharmacokinetics and efficacy of EDP-938 in children with RSV infection.

Start Date26 Apr 2022

Sponsor / Collaborator

Enanta Pharmaceuticals, Inc.

NCT04633187

/ TerminatedPhase 2

A Phase 2b, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Effects of EDP-938 in Hematopoietic Cell Transplant Recipients With Acute Respiratory Syncytial Virus Infection of the Upper Respiratory Tract

This was a Phase 2b, randomized, double-blind, placebo-controlled, multicenter study evaluating the efficacy and safety of EDP-938 in HCT recipients with acute RSV infection and symptoms of URTI.

Start Date07 Jul 2021

Sponsor / Collaborator

Enanta Pharmaceuticals, Inc.

100 Clinical Results associated with Zelicapavir

100 Translational Medicine associated with Zelicapavir

100 Patents (Medical) associated with Zelicapavir

Literatures (Medical) associated with Zelicapavir

20 Feb 2025·JOURNAL OF INFECTIOUS DISEASES

EDP-938 Has a High Barrier to Resistance in Healthy Adults Experimentally Infected with Respiratory Syncytial Virus

Article

Author: Levene, Rachel Emily ; DeVincenzo, John ; Or, Yat Sun ; Conery, Annie L ; Ahmad, Alaa ; Rhodin, Michael H J

Abstract:

Background:

EDP-938 is an oral once-daily RSV nucleoprotein (N) inhibitor with potent antiviral activity. In a human RSV challenge trial, EDP-938 significantly reduced viral load and symptom severity. During antiviral development, it is critical to understand the propensity for resistance to develop. In vitro studies of EDP-938 suggest a higher barrier to resistance as compared to RSV fusion inhibitors. We evaluated the development of viral resistance to EDP-938 in a human challenge trial.

Methods:

A subset of the 124 participants with RSV infection were chosen for genetic analysis; 159 nasal wash samples from 48 participants were analyzed using next-generation sequencing of the N gene of RSV. Of the 48 participant sampled, 37 were from EDP-938–treated and 11 were placebo-treated participants, representing 45% and 26% of the participants, respectively. The effects of treatment-emergent mutations on viral load, EDP-938 efficacy, and viral fitness were evaluated.

Results:

Two of the 37 EDP-938–treated participants with samples sequenced had treatment-emergent mutations: N:L139I and N:E112G. From in vitro analysis, N:L139I reduced sensitivity to EDP-938 by approximately 10-fold, while N:E112G had no effect. However, N:L139I was associated with a reduction in viral fitness, suggesting clinical resistance is associated with fitness costs. Neither of these variants were associated with reduced viral clearance.

Conclusions:

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.

Clinical Trials Registration:

NCT03691623.

16 Dec 2024·JOURNAL OF INFECTIOUS DISEASES

Correction to: EDP-938 Has a High Barrier to Resistance in Healthy Adults Experimentally Infected with Respiratory Syncytial Virus

20 Jan 2023·Revista espanola de quimioterapia : publicacion oficial de la Sociedad Espanola de Quimioterapia

EDP-938, a new antiviral with inhibitory activity against the nucleoprotein of the respiratory syncytial virus

Review

Author: Reina, J ; Iglesias, C

The absence of an effective vaccine against respiratory syncytial virus (RSV) has led to the development of various drugs with the ability to inhibit or block its replicative activity. The first generation, called fusion inhibitors, bind to the protein on the viral surface and prevent the virus from binding and entering the cell. However, its low efficacy has determined the start of studies with second-generation compounds capable of binding or blocking the nucleoprotein (N); most of these compounds are analogs of 1,4-benzodiazepines. 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.

News (Medical) associated with Zelicapavir

27 Jun 2025

·www.fiercebiotech.com

Gilead blames low RSV infection rates last season for scrapping 2 obeldesivir trials

Gilead Sciences\' decision on whether to persevere with obeldesivir will determine whether the company has a place in the respiratory syncytial virus antiviral race.\n Gilead Sciences has blamed the low rate of respiratory syncytial virus (RSV) infections last season for ending two midstage trials of obeldesivir.The pharma had been evaluating the antiviral drug in two RSV studies in adults and children, respectively. However, the company “recently terminated the two trials following lower than expected RSV incidence rates during the most recent RSV season in the Northern Hemisphere, which made it difficult to determine meaningful rates of symptom reduction, a primary endpoint of the study,” Gilead confirmed to Fierce Biotech.The decision to stop the studies “did not reflect any safety or efficacy concerns,” added Gilead, which will share data already accumulated from the trials to “inform a discussion on potential next steps.”With no other RSV candidates listed in Gilead’s pipeline, the decision on whether to persevere with obeldesivir in this indication will determine whether the company still has a place in the RSV antiviral race.It’s not the first time low infection rates have derailed a trial of obeldesivir. Back in 2023, Gilead ended a phase 3 study of the antiviral for COVID-19 based on “lower-than-expected COVID-19 incidence rates and related hospitalizations.”A clinical trial of obeldesivir in Marburg virus, a severe disease that can have a high death rate, is ongoing, Gilead pointed out. Preclinical research has suggested that the antiviral could prove effective against the virus. The RSV market is dominated by vaccines like Pfizer’s Abrysvo and GSK’s Arexvy and Moderna’s mRESVIA along with Sanofi and AstraZeneca’s prophylactic antibody Beyfortus. Merck’s own antibody option Enflonsia has recently secured approval.Meanwhile, a number of companies have demonstrated clinical success with their antiviral candidates in recent months, including Shionogi’s S-337395 and Enanta Pharmaceuticals’ zelicapavir. Despite the dominance of vaccines, Enanta has previously explained that it sees an ongoing need for antivirals in both the pediatric and adult populations, noting babies and children will go on to get RSV infection after protection wanes and that there is low vaccine use in adults.

VaccinePhase 3

22 May 2025

·www.businesswire.com

Enanta Pharmaceuticals Announces Data from its Phase 2 Study of Zelicapavir in Children with Respiratory Syncytial Virus to be Presented at the 43 rd Annual ESPID Meeting

WATERTOWN, Mass.--(BUSINESS WIRE)--Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA), a clinical-stage biotechnology company dedicated to creating small molecule drugs for viral infections and immunological diseases, today announced that data from the Company’s Phase 2 study of zelicapavir in young children infected with respiratory syncytial virus (RSV) will be available as an E-Poster at the 43rd Annual Meeting of the European Society for Paediatric Infectious Diseases (ESPID) 2025, being held May 26-30, 2025 at the Bucharest International Conference Centre in Bucharest, Romania and online. The E-Poster will highlight results from a Phase 2 study of zelicapavir, an oral, non-nucleoside small-molecule RSV-replication-inhibitor (N-protein), which were announced in December 2024, and include new data on the population PK/PD and time to viral load negativity. E-Poster Title: “Antiviral Treatment of RSV in Children: Virology and PK Results of a Randomized Double-Blind Placebo-Controlled International Trial of Zelicapavir (EDP-938)” E-Poster Number: ID 1767 Date and Time: Available starting on May 26, 2025, at 8:00 a.m. Eastern European Summer Time/ 1:00 a.m. Eastern Daylight Time E-Poster Location: Level 0, Main Floor or on the conference portal and the conference app Presenter: John DeVincenzo, M.D. A copy of the E-Poster will be available on Enanta’s website here. The scientific program for ESPID 2025 can be found here. About Enanta Pharmaceuticals, Inc. Enanta is using its robust, chemistry-driven approach and drug discovery capabilities to become a leader in the discovery and development of small molecule drugs with an emphasis on indications in virology and immunology. Enanta’s clinical programs are currently focused on respiratory syncytial virus (RSV) and its earlier-stage immunology pipeline aims to develop treatments for inflammatory diseases by targeting key drivers of the type 2 immune response, including KIT and STAT6 inhibition. Glecaprevir, a protease inhibitor discovered by Enanta, is part of one of the leading treatment regimens for curing chronic hepatitis C virus (HCV) infection and is sold by AbbVie in numerous countries under the tradenames MAVYRET® (U.S.) and MAVIRET® (ex-U.S.) (glecaprevir/pibrentasvir). A portion of Enanta’s royalties from HCV products developed under its collaboration with AbbVie contribute ongoing funding to Enanta’s operations. Please visit www.enanta.com for more information.

Phase 2Clinical Result

22 May 2025

·ir.enanta.com

Enanta Pharmaceuticals Announces Data from its Phase 2 Study of Zelicapavir in Children with Respiratory Syncytial Virus to be Presented at the 43rd Annual ESPID Meeting

WATERTOWN, Mass.--(BUSINESS WIRE)--May 22, 2025-- Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA), a clinical-stage biotechnology company dedicated to creating small molecule drugs for viral infections and immunological diseases, today announced that data from the Company’s Phase 2 study of zelicapavir in young children infected with respiratory syncytial virus (RSV) will be available as an E-Poster at the 43rd Annual Meeting of the European Society for Paediatric Infectious Diseases (ESPID) 2025, being held May 26-30, 2025 at the Bucharest International Conference Centre in Bucharest, Romania and online. The E-Poster will highlight results from a Phase 2 study of zelicapavir, an oral, non-nucleoside small-molecule RSV-replication-inhibitor (N-protein), which were announced in December 2024, and include new data on the population PK/PD and time to viral load negativity. E-Poster Title: “Antiviral Treatment of RSV in Children: Virology and PK Results of a Randomized Double-Blind Placebo-Controlled International Trial of Zelicapavir (EDP-938)” E-Poster Number: ID 1767 Date and Time: Available starting on May 26, 2025, at 8:00 a.m. Eastern European Summer Time/ 1:00 a.m. Eastern Daylight Time E-Poster Location: Level 0, Main Floor or on the conference portal and the conference app Presenter: John DeVincenzo, M.D. A copy of the E-Poster will be available on Enanta’s website here. The scientific program for ESPID 2025 can be found here. About Enanta Pharmaceuticals, Inc. Enanta is using its robust, chemistry-driven approach and drug discovery capabilities to become a leader in the discovery and development of small molecule drugs with an emphasis on indications in virology and immunology. Enanta’s clinical programs are currently focused on respiratory syncytial virus (RSV) and its earlier-stage immunology pipeline aims to develop treatments for inflammatory diseases by targeting key drivers of the type 2 immune response, including KIT and STAT6 inhibition. Glecaprevir, a protease inhibitor discovered by Enanta, is part of one of the leading treatment regimens for curing chronic hepatitis C virus (HCV) infection and is sold by AbbVie in numerous countries under the tradenames MAVYRET® (U.S.) and MAVIRET® (ex-U.S.) (glecaprevir/pibrentasvir). A portion of Enanta’s royalties from HCV products developed under its collaboration with AbbVie contribute ongoing funding to Enanta’s operations. Please visit www.enanta.com for more information. View source version on businesswire.com: https://www.businesswire.com/news/home/20250522937132/en/ Media and Investor Jennifer Viera 617-744-3848 jviera@enanta.com Source: Enanta Pharmaceuticals, Inc.

Phase 2Clinical Result

100 Deals associated with Zelicapavir

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Indication	Highest Phase	Country/Location	Organization	Date
Respiratory Syncytial Virus Infections	Phase 2	United Kingdom	Enanta Pharmaceuticals, Inc.	15 Oct 2018

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Study	Phase	Population	Analyzed Enrollment	Group	Results	Evaluation	Publication Date


NCT04816721 (Company_Website) Manual	Phase 2	Respiratory Syncytial Virus Infections	96	zelicapavir	hwpqricltg(cpvfgbvzlg) = okcqgoepyj toefphezgn (zhlpttxoyl ) View more	Positive	09 Dec 2024
				placebo	hwpqricltg(cpvfgbvzlg) = patfdhruym toefphezgn (zhlpttxoyl ) View more
NCT04633187 (RSVTx, CTgov)	Phase 2	Respiratory Syncytial Virus Infections	9	EDP-938 (EDP-938)	dxkoavkjbx = yopvffmofi axjgzmofcy (mwifrotqzi, rmspmipthq - cxgarwqpzq) View more	-	22 Aug 2024
				Placebo (Placebo)	dxkoavkjbx = izbdzkdqoz axjgzmofcy (mwifrotqzi, yegtmglybv - jypbywaezu) View more
NCT04196101 (RSVP, CTgov)	Phase 2	Respiratory Syncytial Virus Infections	82	EDP-938 (EDP-938)	odclqhplwl(npusmbkqnv) = ffealvgzvj yajwyzlizu (fbblsplzyc, 97.180) View more	-	30 Oct 2023
				Placebo (Placebo)	odclqhplwl(npusmbkqnv) = jkxsahzgpv yajwyzlizu (fbblsplzyc, 40.310) View more
NCT04196101 (RSVP, Biospace) Manual	Phase 2	Respiratory Syncytial Virus Infections	81	EDP-938	hlwyuaguuo(ukrjafvjjv) = The AUC for the mean total symptom score (days x score) was not statistically different between the two groups slilksjczk (witrvgmuvf ) View more	Negative	18 May 2022
				Placebo
NCT03691623 (CTgov)	Phase 2	Respiratory Syncytial Virus Infections	179	EDP-938 (Part 1: EDP-938 600 mg)	evulhqejai(alladeqhad) = edqhvdvlyg kelgutpsje (okqsbhupqm, 85.1) View more	-	03 May 2022
				EDP-938 (Part 1: EDP-938 500 mg Then 300 mg)	evulhqejai(alladeqhad) = qstkzzdwmz kelgutpsje (okqsbhupqm, 99.9) View more

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