Assessing Antiviral Treatments in Early Symptomatic RSV (ARSYNAL-FC)

June 27, 2025 updated by: University of Oxford

Assessment of Respiratory SYNcytial Virus antivirALs: A Phase 2 Multi-centre Adaptive Randomised Platform Trial For the Assessment of Antiviral Pharmacodynamics in aCute Symptomatic RSV Infection (ARSYNAL-FC)

This trial will use a previously validated platform, to quantitatively assess antiviral effects in low-risk patients with high viral burdens and uncomplicated Respiratory Syncytial Virus (RSV), to determine in-vivo antiviral activity. In this randomised, open-label, controlled, group sequential adaptive platform trial, we will assess and compare the performance of currently licensed interventions (including repurposed drugs) with activity against RSV, and those with potential activity demonstrated in pre-clinical and early clinical studies relative to each-other, and the control (no antiviral treatment).

ARSYNAL-FC study is funded by Wellcome Trust Grant ref: 226933/Z/23/Z through the COVID-19 Therapeutics Accelerator

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

There are no proven effective drug treatments for RSV. While vaccines are becoming available, and monoclonal antibodies exist for prevention in infants, antiviral treatments are still urgently needed.

The study is a randomised, open label, controlled, adaptive platform trial that will be conducted in low-risk adult patients (18 - <65 years old) with early symptomatic RSV, recruited from outpatient acute respiratory infection clinics (ARIs), other approved facilities, or by patient self-referral to the study site. The primary pharmacodynamic measure in this study is the rate of viral clearance following treatment. Individual patient's involvement for this study is 28 days.

This platform will compare antivirals with potential RSV antiviral activity, against a negative control (no treatment). Currently, interventions included in the platform are;

  • Interventions licensed for paediatric RSV infections: ribavirin.
  • Interventions with antiviral activity against RSV demonstrated in in-vitro studies: molnupiravir and favipiravir

Randomisation to the no antiviral treatment control arm (no intervention) will be fixed at a minimum of 20% throughout the study. The randomisation ratios will be uniform for all available interventions.

Study Type

Interventional

Enrollment (Estimated)

1000

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patient understands the procedures and requirements and is willing and able to give informed consent for full participation in the study
  • Adults, male or female, aged ≥18 to <65 years at time of consent
  • Early symptomatic RSV; at least one reported symptom of RSV (including fever, history of fever, myalgias, headache, cough, fatigue, nasal congestion, rhinorrhoea and sore throat) within 4 days (96 hours)
  • RSV positive by rapid antigen test OR a positive RT-PCR test for RSV viruses within the last 24hrs with a Ct value of <30
  • Able to walk unaided and unimpeded in activities of daily living (ADLs)
  • Agrees and is able to adhere to all study procedures, including availability and contact information for follow-up visits

Exclusion Criteria:

The patient may not enter the study if ANY of the following apply:

  • Taking any concomitant medications or drugs which could interact with the study medications or have antiviral activity
  • Presence of any chronic illness/condition requiring long term treatment or other significant comorbidity
  • BMI ≥35 Kg/m2

  • Clinically relevant laboratory abnormalities discovered at screening

    • Haemoglobin <10g/dL (<12g/dL for all arms if Ribavirin is in the randomisation)
    • Platelet count <100,000/uL
    • ALT > 2x ULN
    • Total bilirubin >1.5 x ULN
    • eGFR <70mls/min/1.73m2
  • For females: pregnancy, actively trying to become pregnant or lactating (women on OCP are eligible to join)
  • Contraindication to taking, or known hypersensitivity reaction to any of the proposed therapeutics
  • Currently participating in another interventional RSV, influenza or COVID-19 therapeutic trial
  • Clinical evidence of pneumonia- e.g., shortness of breath, hypoxaemia, crepitations (imaging not required)
  • Known to be currently co-infected with influenza or SARS-CoV-2 (i.e. confirmed with positive ATK or RT-PCR)
  • Received any RSV vaccine within the last year

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Molnupiravir
Drug: Molnupiravir
Oral molnupiravir 800mg BD for 5 days
No Intervention: Negative control group
Controls will receive no antiviral treatment (supportive treatment will remain the same as per the treating Physician's judgement)
Experimental: Ribavirin
[Pending addition]
Drug: Ribavirin

Oral ribavirin 400 to 1000mg three times a day for 5 days. Each tablet contains 200mg, The total daily dosage in adults is weight dependent as outlined below;

  • 40-59.9kg = 1200mg/day
  • 60-79.9kg = 1800mg/day
  • 80-99.9kg = 2400mg/day
  • ≥100kg = 3000mg/day
Experimental: Favipiravir
[Pending addition]
Drug: Favipiravir
Oral favipiravir 1800mg BD on Day 0, and 800mg BD for a further 4 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rate of viral clearance for interventions relative to no study drug arm (superiority comparison)
Time Frame: Days 0-5
Rate of viral clearance- estimated from the log10 viral density derived from qPCR of standardised duplicate oropharyngeal swabs taken daily from baseline (day 0) to day 5 for each therapeutic arm compared with the contemporaneous no antiviral treatment control/ positive control
Days 0-5

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rate of RSV clearance in early infection
Time Frame: Days 0-5
Rate of viral clearance in early RSV infection to characterise the determinants of RSV clearance in early infection e.g., contribution of baseline serology, virus type/subtype, prior vaccination, host genetics
Days 0-5
Rate of RSV clearance for drugs with evidence of antiviral activity
Time Frame: Days 0-5
Rate of viral clearance to determine optimal dosing regimens for drugs with evidence of antiviral activity
Days 0-5
Assessment of time to symptom alleviation across interventions
Time Frame: Days 0-14
Time to symptom resolution across interventions
Days 0-14
Assessment of fever duration across interventions
Time Frame: Days 0-14
Area under the curve of recorded temperature across interventions
Days 0-14
Effects of drugs on the development of drug resistant viral mutants
Time Frame: Days 0-14
To determine the effects of drugs on the development of drug resistant viral mutants between intervention and no treatment arm, measuring the number of mutations known to confer resistance in detectable virus at later time points
Days 0-14

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Hospitalisation for clinical reasons
Time Frame: Days 0-28
To characterise the relationship between viral clearance and hospitalisation for clinical reasons up to day 28
Days 0-28
Number of participants with virus-related complications
Time Frame: Days 0-28
Number of participants with virus-related complications including bronchitis, sinusitis, otitis media and pneumonia requiring antibiotics, up to day 28, where the diagnosis is made and documented by the study clinician.
Days 0-28

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Oxford

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 25, 2024

Primary Completion (Estimated)

January 1, 2027

Study Completion (Estimated)

January 1, 2027

Study Registration Dates

First Submitted

June 19, 2024

First Submitted That Met QC Criteria

June 27, 2024

First Posted (Actual)

July 5, 2024

Study Record Updates

Last Update Posted (Actual)

July 2, 2025

Last Update Submitted That Met QC Criteria

June 27, 2025

Last Verified

June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VIR24001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

With patient's consent, clinical data and results from blood analyses stored in the database may be shared according to the terms defined in the MORU data sharing policy with other researchers to use in the future. https://wellcome.ac.uk/press-release/statement-data-sharing-public-health-emergencies).

IPD Sharing Access Criteria

Refer to MORU data sharing policy with other researchers to use in the future. https://wellcome.ac.uk/press-release/statement-data-sharing-public-health-emergencies).

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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