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Safety, Pharmacokinetics,and Antiviral Activity of RV299 Against Respiratory Syncytical Virus (RSV)

A RANDOMISED, PHASE 1B, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY TO EVALUATE THE SAFETY, PHARMACOKINETICS, AND ANTIVIRAL ACTIVITY OF RV299 AGAINST RESPIRATORY SYNCYTIAL VIRUS IN THE VIRAL CHALLENGE MODEL

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06067191
Enrollment
82
Registered
2023-10-04
Start date
2022-08-08
Completion date
2022-12-02
Last updated
2024-10-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Respiratory Syncytial Virus (RSV)

Keywords

Anti-viral, Challenge

Brief summary

The purpose of the study is to learn about the safety, pharmacokinetics and antiviral activity of the study medicine (RV299) for the potential treatment of respiratory syncytial virus (RSV). RSV is a highly contagious virus that can lead to serious lung infections in patients with reduced ability to fight infection. Most vulnerable populations include babies, the elderly and patients that have received a bone marrow transplant.

Detailed description

This study is seeking healthy participants who are: Healthy adult male and female participants aged between 18 to 55 years, with a total body weight ≥50 kg and body mass index (BMI) ≥18 kg/m2 and ≤35kg/m2 and who have been screened to be sero-suitable for infection with the RSV-A Memphis 37b virus challenge virus. A total of 80 participants is planned: 40 participants on RV299 and 40 participants on placebo. The study is divided into 3 phases: * Screening phase: from Day -90 to Day-3 pre-human viral challenge (HVC). * Inpatient phase: Participants will be resident in the quarantine unit for approximately 15 days (from Day -2 to Day 12). * Post RSV-A Memphis 37b virus inoculation on Day 0, participants will be randomized to receive RV299 or matched placebo. * Administration of RV299 or placebo will be twice daily (\ 12 hours interval) for 5 consecutive days and will start on confirmation of RSV infection. * Outpatient phase: Day 28 (±3 days)

Interventions

DRUGPlacebo

matching placebo

DRUGRV299

Oral Suspension

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

* Total body weight \>= 50 kg and body mass index (BMI) \>=18 kg/m2 and \<=35 kg/m2 * in good health with no history, or current evidence of clinically significant medical condition of laboratory, ECG or vital sign abnormality * Sero suitable for challenge virus

Exclusion criteria

* History of or currently active symptoms or signs suggestive of upper or lower respiratory tract infection within 4 weeks prior to first study visit * Any history or evidence of any clinically significant or currently active cardiovascular, respiratory, dermatological, gastrointestinal, endocrinological, haematological, hepatic, immunological (including immunosuppression),metabolic, urological, renal, neurological, or psychiatric disease and/or other major disease * females who are breastfeeding or have been pregnant within 6 months prior to the study or have a positive pregnancy test * Lifetime history of anaphylaxis and/or a lifetime history of severe allergic reaction * Any significant abnormality altering the anatomy of the nose in a substantial way * Any clinically significant history of epistaxis (large nosebleeds) * Any nasal or sinus surgery within 3 months of first study visit * Evidence of vaccinations within 4 weeks of Day 0 * Receipt of blood or blood products, or loss of 550 mL or more blood within last 3 months * Receipt of 3 or more investigational drug within last 12 months * Prior inoculation with a virus from the same virus-family as the challenge * Prior participation in another HVC study with a respiratory virus in last 3 months * Use or anticipated use during the conduct of the study of protocol specified concomitant medications * Systemic antiviral administration within 4 weeks of viral challenge * Confirmed positive test for drugs of abuse * History or presence of alcohol addiction, or excessive use of alcohol * A forced expiratory volume in 1 second (FEV1) \<80% * Positive HIV, hepatitis B virus, or hepatitis C virus test * Presence of fever upto 2 days prior to Day 0.

Design outcomes

Primary

MeasureTime frameDescription
Area Under the Curve (AUC) for RSV-A Memphis 37b Viral Load Determined by Quantitative Real Time Reverse Transcription Polymerase Chain Reaction (qRT-PCR)From initial administration of IMP up to the morning of quarantine discharge (up to Day 12)Area under the curve (AUC) for RSV viral load measured in nasal washes by qRT-PCR in participants inoculated with RSV-A Memphis 37b, from initial administration of IMP up to the morning of Day 12 (Quarantine discharge) was presented in this outcome measure.

Secondary

MeasureTime frameDescription
Time to Confirmed Negative Test by qRT-PCR Measurement Starting From Initial Administration of Investigational Medicinal Product (IMP) to First Confirmed Undetectable Assessment After Peak MeasureFrom first administration of IMP to the first confirmed negative qRT-PCR test or censoring date (up to Day 12)The time from the first administration of IMP to the first confirmed negative qRT-PCR test after the peak qRT-PCR measurement was calculated as: Date and time of first confirmed negative test after peak qRT-PCR measurement minus Date and time of first IMP administration. A negative test was defined as two consecutive 'Not Detected' results in the qRT-PCR test. The peak qRT-PCR was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants without a confirmed undetectable assessment after their peak, were censored at their last detected qRT-PCR assessment.
Time to Confirmed Negative Test by qRT-PCR Measurement Starting From Peak qRT-PCR After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak MeasureFrom peak qRT-PCR measurement to the first confirmed negative qRT-PCR test or censoring date (up to Day 12)The time from the peak qRT-PCR measurement after administration of IMP to the first confirmed negative qRT-PCR test was calculated as (Date and time of first confirmed negative test after peak qRT-PCR measurement minus Date and time of peak qRT-PCR measurement). A negative test was defined as two consecutive 'Not Detected' results in the qRT-PCR test. The peak qRT-PCR was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants without a confirmed undetectable assessment after their peak, were censored at their last detected qRT-PCR assessment.
Time to Peak qRT-PCR Starting From Initial Administration of IMPFrom first administration of IMP to peak qRT-PCR measurement (up to Day 12)The time to the peak qRT-PCR measurement starting from the initial administration of IMP was calculated as: Date and time of peak qRT-PCR measurement minus Date and time of first IMP administration. The peak qRT-PCR was defined as the highest viral load value obtained by a participant after their first administration of IMP.
Area Under the Viral Load-Time Curve (VL-AUC) for RSV-A Memphis 37b Determined by Viral CultureFrom initial administration of IMP up to planned discharge from quarantine (up to Day 12)Area under the viral load-time curve (VL-AUC) of RSV challenge virus as determined by viral culture on nasal samples, starting at initial administration of IMP up to planned discharge from quarantine was reported in this outcome measure.
Peak Viral Load of RSV Determined by Viral CultureFrom initial administration of IMP up to planned discharge from quarantine (up to Day 12)Peak viral load of RSV as defined by the maximum viral load determined by viral culture measurements in nasal samples starting from initial administration of IMP up to planned discharge from quarantine was reported in this outcome measure.
Time to Confirmed Negative Test by Viral Culture Measurement Starting From at Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak MeasureFrom initial administration of IMP up to first confirmed undetectable assessment or censoring date (up to Day 12)Time to confirmed negative test by viral culture measurements in nasal samples from initial administration of IMP up to first confirmed negative viral culture measurement after the peak viral culture measurement was calculated as: Date and time of first confirmed negative test after peak viral culture measurement minus Date and time of first IMP administration. A negative test was defined as two consecutive 'Not Detected' results in the viral culture test. The peak viral culture measurement was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants who did not have a confirmed undetectable assessment after their peak viral culture measurement after first administration of IMP were censored at their last detectable assessment.
Time to Confirmed Negative Test by Viral Culture Measurement Starting From Peak Viral Culture After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak MeasureFrom peak qRT-PCR measurement to first confirmed undetectable assessment or censoring date (up to Day 12)The time from the peak viral culture measurement after administration of IMP to the first confirmed negative viral culture measurement was calculated in days as: Date of and time first confirmed negative test minus Date and time of peak qRT-PCR measurement. A negative test was defined as two consecutive 'Not Detected' results in the viral culture test. The peak viral culture measurement was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants who did not have a confirmed undetectable assessment after their peak viral culture measurement after first administration of IMP were censored at their last detectable assessment.
Area Under the Curve Over Time of Total Clinical Symptoms as Measured From 10 Symptoms Within the Graded Symptom Scoring SystemFrom initial administration of IMP (before or after administration) up to planned discharge from quarantine (up to Day 12)Area under the Curve over Time of Total Clinical Symptoms (TSS-AUC) as measured from 10 symptoms within Graded Symptom Scoring System Collected 3 Times Daily Starting at Initial Administration up to Planned Discharge from Quarantine. TSS (from 10 items of the 13-item symptom diary card) was used to calculate the AUC, from the assessment nearest to the time of the first administration of IMP until Day 12. Following types of symptoms were recorded on symptom diary cards: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), higher scores = greater severity of symptoms. Total symptom score was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms.
Area Under the Curve Over Time of Total Clinical Symptoms Change From Baseline (TSS-AUC-CFB) as Measured From 10 Symptoms Within the Graded Symptom Scoring SystemBaseline (assessment nearest to the time of the first administration of IMP) up to Day 12Area under the curve over time of total clinical symptoms change from baseline (TSS-AUC-CFB) as measured from 10 symptoms within the graded symptom scoring system collected 3 times daily starting at initial administration of IMP up to planned discharge from quarantine (Day 12, am). The following types of symptoms were recorded: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), where higher scores indicated greater severity of symptoms. TSS was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms. The AUC calculation was based on the available non-missing calculated total symptom scores between the start and end of the defined AUC time.
Overall Peak Total Clinical Symptoms (TSS) ScoreFrom initial administration of IMP (before or after administration) up to planned discharge from quarantine (up to Day 12)Peak total clinical symptoms (TSS) as measured from 10 symptoms within the graded symptom scoring system collected 3 times daily starting from initial administration of IMP up to planned discharge from quarantine. The following types of symptoms were recorded: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), where higher scores indicated greater severity of symptoms. The total symptom score was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms. The overall peak score was defined as the highest scoring symptom diary card observed from the first administration of IMP until quarantine discharge.
Individual Maximum Daily Peak Symptom ScoreDay 0, Day 1, Day 2, Day 3, Day 4, Day 5, Day 6, Day 7, Day 8 and Day 9 (days relative to first administration of IMP)Individual maximum daily sum of symptom score from initial administration of IMP up to planned discharge from quarantine. The following types of symptoms were recorded: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), where higher scores indicated greater severity of symptoms. The total symptom score was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms. The highest total symptom score recorded on each day, across the three assessments was reported in this outcome measure. The peak daily score was defined as the highest scoring symptom diary card observed on each day from the first administration of IMP until quarantine discharge.
Time to Symptom Resolution Starting at Initial Administration of IMP to 24 Hours Symptom FreeFrom first administration of IMP until time of symptom resolution or censoring date (up to Day 12)Symptom resolution was defined as a participant scoring 0 for the total symptom score for a 24-hour period (e.g., a minimum of three consecutive symptom diary cards, each with a score of 0) after their peak symptom score. The time from the assessment at the time of the first administration of IMP until symptom resolution was calculated as: Date and time of symptom resolution minus Date and time of assessment at IMP administration. If the peak symptom score occurred on more than one day then the first occurrence was selected. Participants who did not record 24 hours symptom free after their highest total symptom score during the quarantine period were censored at their last assessment.
Peak Viral Load of RSV Determined by qRT-PCRFrom initial administration of IMP up to planned discharge from quarantine (Up to Day 12)Peak viral load of RSV as defined by the maximum viral load determined by qRT-PCR measurements in nasal samples starting from initial administration of IMP up to planned discharge from quarantine was reported in this outcome measure.
Time to Peak Symptom Score From Initial Administration of IMPFrom first dose of IMP until time of highest total symptom score or censoring date (Up to Day 12)Time to peak as measured from 10 symptoms within the graded daily symptom scoring system starting from initial administration of IMP to the time of peak daily symptom score. If the peak symptom score occurred on more than one day then the first occurrence was selected. Participants were censored at their last assessment if they did not record any symptoms during the quarantine period.
Total Weight of Mucus Produced Starting at Initial Administration of IMP up to Planned Discharge From QuarantineFrom first administration of IMP up to planned discharge from quarantine (up to Day 12)Total weight of nasal mucus was calculated as the sum of mucus weights taken from the assessment at the time of the first administration of IMP (prior to or after dosing, depending on whether dosed in the morning or evening) to morning of Day 12 (Quarantine discharge).
Total Number of Tissues Used by Participants Starting At Initial Administration of IMP up to Planned Discharge From QuarantineFrom first administration of IMP up to planned discharge from quarantine (up to Day 12)Total number of tissues was counted from the assessment at the time of the first dose of IMP (prior to or after dosing, depending on whether dosed in the morning or evening) to morning of Day 12 (Quarantine discharge).
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)From first dose of IMP until end of follow-up visit (up to Day 28)An adverse event was defined as any untoward medical occurrence in clinical study participants administered a pharmaceutical product. An AE did not necessarily have a causal relationship with the study intervention. An SAE was defined as any untoward medical occurrence that, at any dose: resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent disability/incapacity, was a congenital anomaly/birth defect or important medical event.
Number of Participants With AEs Related to Viral ChallengeFrom viral challenge on Day 0 up to end of follow-up (Day 28)An Adverse Event was defined as any untoward medical occurrence in clinical study participants administered a pharmaceutical product. An AE did not necessarily have a causal relationship with the study intervention. Number of participants with AEs possibly, probably or definitely related to viral challenge agents were reported by preferred terms in this outcome measure.
Number of Participants With Concomitant MedicationsFrom viral challenge on Day 0 up to end of follow-up (Day 28)Number of participants with concomitant medications were reported in this outcome measure.
Time to Maximum Plasma Concentration (Tmax) for RV299Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96-hours post-dose 1 and dose 10
Terminal Half-Life (t1/2) for RV299Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96 hours post-dose 1 and dose 10
Maximum Observed Plasma Concentration for RV299Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96 hours post-dose 1 and dose 10
Area Under the Plasma Concentration-Time Curve From Time Zero to the End of the Dosing Interval for RV299Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12 hours post-dose 1 and dose 10Area under the plasma concentration-time curve from time zero to the end of the dosing interval for RV299 where dosing interval=12 hours.
Area Under the Plasma Concentration-Time Curve Over the Last 24 Hours Dosing Interval for RV299Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24 hours post-dose 1 and dose 10
Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity for RV299 on Day 1Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96 hours post-dose 1
Time to Symptom Resolution Starting at Peak Symptoms After Initial Administration to 24 Hours Symptom FreeFrom time of highest total symptom score until time of symptom resolution or censoring date (up to Day 12)Symptom resolution was defined as a participant scoring 0 for the total symptom score for a 24-hour period (e.g., a minimum of three consecutive symptom diary cards, each with a score of 0) after their peak symptom score. The time from the highest total symptom score following administration of IMP until symptom resolution was calculated as: Date and time of symptom resolution minus Date and time of highest total symptom score. If the peak symptom score occurred on more than one day then the first occurrence was selected. Participants who did not record 24 hours symptom free after their highest total symptom score during the quarantine period were censored at their last assessment.

Countries

United Kingdom

Participant flow

Pre-assignment details

A total of 82 healthy participants were enrolled in the study and received Respiratory Syncytial Virus (RSV) - A Memphis 37b virus inoculation (challenge agent) intranasally on Day 0. Three participants withdrew from study (2 withdrew consent and 1 not randomized because of influenza infection) before randomization and a total of 79 participants were randomized in the study.

Participants by arm

ArmCount
RV299
Participants were administered an oral suspension of 65 milligrams (mg) RV299 twice daily at an interval of approximately 12 hours for 5 consecutive days from Day 2 following confirmation of RSV infection. Participants without a positive result for RSV infection were administered RV299 from Day 5.
39
Placebo
Participants were administered an oral suspension of placebo twice daily at an interval of approximately 12 hours for 5 consecutive days from Day 2 following confirmation of RSV infection. Participants without a positive result for RSV infection were administered placebo from Day 5.
40
Total79

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyWithdrawal by Subject01

Baseline characteristics

CharacteristicPlaceboTotalRV299
Age, Continuous26.2 Years
STANDARD_DEVIATION 7.29
25.9 Years
STANDARD_DEVIATION 6.74
25.7 Years
STANDARD_DEVIATION 6.21
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
2 Participants4 Participants2 Participants
Race (NIH/OMB)
Black or African American
4 Participants7 Participants3 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
4 Participants8 Participants4 Participants
Race (NIH/OMB)
White
30 Participants60 Participants30 Participants
Sex: Female, Male
Female
17 Participants34 Participants17 Participants
Sex: Female, Male
Male
23 Participants45 Participants22 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 390 / 40
other
Total, other adverse events
12 / 3912 / 40
serious
Total, serious adverse events
0 / 390 / 40

Outcome results

Primary

Area Under the Curve (AUC) for RSV-A Memphis 37b Viral Load Determined by Quantitative Real Time Reverse Transcription Polymerase Chain Reaction (qRT-PCR)

Area under the curve (AUC) for RSV viral load measured in nasal washes by qRT-PCR in participants inoculated with RSV-A Memphis 37b, from initial administration of IMP up to the morning of Day 12 (Quarantine discharge) was presented in this outcome measure.

Time frame: From initial administration of IMP up to the morning of quarantine discharge (up to Day 12)

Population: Intent-to-Treat Infected (ITT-I) Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Area Under the Curve (AUC) for RSV-A Memphis 37b Viral Load Determined by Quantitative Real Time Reverse Transcription Polymerase Chain Reaction (qRT-PCR)350.99 Hours*log10 copies per milliliterStandard Deviation 289.79
PlaceboArea Under the Curve (AUC) for RSV-A Memphis 37b Viral Load Determined by Quantitative Real Time Reverse Transcription Polymerase Chain Reaction (qRT-PCR)616.97 Hours*log10 copies per milliliterStandard Deviation 374.143
p-value: 0.000995% CI: [-489.17, -135.38]ANCOVA
Secondary

Area Under the Curve Over Time of Total Clinical Symptoms as Measured From 10 Symptoms Within the Graded Symptom Scoring System

Area under the Curve over Time of Total Clinical Symptoms (TSS-AUC) as measured from 10 symptoms within Graded Symptom Scoring System Collected 3 Times Daily Starting at Initial Administration up to Planned Discharge from Quarantine. TSS (from 10 items of the 13-item symptom diary card) was used to calculate the AUC, from the assessment nearest to the time of the first administration of IMP until Day 12. Following types of symptoms were recorded on symptom diary cards: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), higher scores = greater severity of symptoms. Total symptom score was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms.

Time frame: From initial administration of IMP (before or after administration) up to planned discharge from quarantine (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Area Under the Curve Over Time of Total Clinical Symptoms as Measured From 10 Symptoms Within the Graded Symptom Scoring System180.77 Hours*scoreStandard Deviation 242.274
PlaceboArea Under the Curve Over Time of Total Clinical Symptoms as Measured From 10 Symptoms Within the Graded Symptom Scoring System240.94 Hours*scoreStandard Deviation 224.439
p-value: 0.065895% CI: [-194.26, 6.36]ANCOVA
Secondary

Area Under the Curve Over Time of Total Clinical Symptoms Change From Baseline (TSS-AUC-CFB) as Measured From 10 Symptoms Within the Graded Symptom Scoring System

Area under the curve over time of total clinical symptoms change from baseline (TSS-AUC-CFB) as measured from 10 symptoms within the graded symptom scoring system collected 3 times daily starting at initial administration of IMP up to planned discharge from quarantine (Day 12, am). The following types of symptoms were recorded: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), where higher scores indicated greater severity of symptoms. TSS was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms. The AUC calculation was based on the available non-missing calculated total symptom scores between the start and end of the defined AUC time.

Time frame: Baseline (assessment nearest to the time of the first administration of IMP) up to Day 12

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Area Under the Curve Over Time of Total Clinical Symptoms Change From Baseline (TSS-AUC-CFB) as Measured From 10 Symptoms Within the Graded Symptom Scoring System-17.23 Hours*scoreStandard Deviation 202.602
PlaceboArea Under the Curve Over Time of Total Clinical Symptoms Change From Baseline (TSS-AUC-CFB) as Measured From 10 Symptoms Within the Graded Symptom Scoring System103.75 Hours*scoreStandard Deviation 212.465
p-value: 0.065895% CI: [-194.26, 6.36]ANCOVA
Secondary

Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity for RV299 on Day 1

Time frame: Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96 hours post-dose 1

Population: PK population consisted of all participants from ITT population (all randomized participants who received challenge virus and at least 1 dose of IMP) with at least one post-dose PK result. AUC(0-infinity) could not be calculated as atleast 3 data points are required in terminal elimination phase within same participant; this criteria could not be fulfilled due to insufficient data above limit of quantification and did not include a characterization of the terminal elimination.

ArmMeasureValue (GEOMETRIC_MEAN)
RV299Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity for RV299 on Day 1NA Hours*nanograms per milliliter
Secondary

Area Under the Plasma Concentration-Time Curve From Time Zero to the End of the Dosing Interval for RV299

Area under the plasma concentration-time curve from time zero to the end of the dosing interval for RV299 where dosing interval=12 hours.

Time frame: Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12 hours post-dose 1 and dose 10

Population: PK population consisted of all participants from ITT population (all randomized participants who received challenge virus and at least 1 dose of IMP) with at least one post-dose PK result Here, 'Number Analyzed' signifies participants evaluable for the specified timepoints.

ArmMeasureGroupValue (GEOMETRIC_MEAN)Dispersion
RV299Area Under the Plasma Concentration-Time Curve From Time Zero to the End of the Dosing Interval for RV299Dose 13500 Hours*nanograms per milliliterGeometric Coefficient of Variation 825
RV299Area Under the Plasma Concentration-Time Curve From Time Zero to the End of the Dosing Interval for RV299Dose 107845 Hours*nanograms per milliliterGeometric Coefficient of Variation 3004
Secondary

Area Under the Plasma Concentration-Time Curve Over the Last 24 Hours Dosing Interval for RV299

Time frame: Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24 hours post-dose 1 and dose 10

Population: PK population consisted of all participants from ITT population (all randomized participants who received challenge virus and at least 1 dose of IMP) with at least one post-dose PK result. Only participants with evaluable results for this PK parameter were reported.

ArmMeasureValue (GEOMETRIC_MEAN)
RV299Area Under the Plasma Concentration-Time Curve Over the Last 24 Hours Dosing Interval for RV299NA Hours*nanograms per milliliter
Secondary

Area Under the Viral Load-Time Curve (VL-AUC) for RSV-A Memphis 37b Determined by Viral Culture

Area under the viral load-time curve (VL-AUC) of RSV challenge virus as determined by viral culture on nasal samples, starting at initial administration of IMP up to planned discharge from quarantine was reported in this outcome measure.

Time frame: From initial administration of IMP up to planned discharge from quarantine (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Area Under the Viral Load-Time Curve (VL-AUC) for RSV-A Memphis 37b Determined by Viral Culture106.48 Hours*log10 plaque forming units/mLStandard Deviation 133.187
PlaceboArea Under the Viral Load-Time Curve (VL-AUC) for RSV-A Memphis 37b Determined by Viral Culture212.51 Hours*log10 plaque forming units/mLStandard Deviation 170.7
p-value: 0.026895% CI: [-164.3, -10.49]ANCOVA
Secondary

Individual Maximum Daily Peak Symptom Score

Individual maximum daily sum of symptom score from initial administration of IMP up to planned discharge from quarantine. The following types of symptoms were recorded: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), where higher scores indicated greater severity of symptoms. The total symptom score was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms. The highest total symptom score recorded on each day, across the three assessments was reported in this outcome measure. The peak daily score was defined as the highest scoring symptom diary card observed on each day from the first administration of IMP until quarantine discharge.

Time frame: Day 0, Day 1, Day 2, Day 3, Day 4, Day 5, Day 6, Day 7, Day 8 and Day 9 (days relative to first administration of IMP)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection. Here, 'Number Analyzed' signifies participants evaluable for the specified timepoints.

ArmMeasureGroupValue (MEAN)Dispersion
RV299Individual Maximum Daily Peak Symptom ScoreDay 02.1 Units on a scaleStandard Deviation 2.32
RV299Individual Maximum Daily Peak Symptom ScoreDay 12.0 Units on a scaleStandard Deviation 2.7
RV299Individual Maximum Daily Peak Symptom ScoreDay 21.9 Units on a scaleStandard Deviation 2.73
RV299Individual Maximum Daily Peak Symptom ScoreDay 31.9 Units on a scaleStandard Deviation 2.83
RV299Individual Maximum Daily Peak Symptom ScoreDay 41.1 Units on a scaleStandard Deviation 1.71
RV299Individual Maximum Daily Peak Symptom ScoreDay 50.7 Units on a scaleStandard Deviation 1.27
RV299Individual Maximum Daily Peak Symptom ScoreDay 60.6 Units on a scaleStandard Deviation 1.12
RV299Individual Maximum Daily Peak Symptom ScoreDay 70.6 Units on a scaleStandard Deviation 1.16
RV299Individual Maximum Daily Peak Symptom ScoreDay 81.0 Units on a scaleStandard Deviation 1.22
RV299Individual Maximum Daily Peak Symptom ScoreDay 90.0 Units on a scaleStandard Deviation 0
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 71.1 Units on a scaleStandard Deviation 1.53
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 01.2 Units on a scaleStandard Deviation 1.7
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 51.6 Units on a scaleStandard Deviation 2.11
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 11.8 Units on a scaleStandard Deviation 2.12
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 90.0 Units on a scaleStandard Deviation 0
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 23.0 Units on a scaleStandard Deviation 3.01
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 61.0 Units on a scaleStandard Deviation 1.86
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 32.6 Units on a scaleStandard Deviation 2.54
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 80.4 Units on a scaleStandard Deviation 0.51
PlaceboIndividual Maximum Daily Peak Symptom ScoreDay 42.1 Units on a scaleStandard Deviation 2.17
Secondary

Maximum Observed Plasma Concentration for RV299

Time frame: Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96 hours post-dose 1 and dose 10

Population: PK population consisted of all participants from ITT population (all randomized participants who received challenge virus and at least 1 dose of IMP) with at least one post-dose PK result.

ArmMeasureGroupValue (GEOMETRIC_MEAN)Dispersion
RV299Maximum Observed Plasma Concentration for RV299Dose 1448 Nanograms per milliliterGeometric Coefficient of Variation 155
RV299Maximum Observed Plasma Concentration for RV299Dose 101144 Nanograms per milliliterGeometric Coefficient of Variation 647
Secondary

Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

An adverse event was defined as any untoward medical occurrence in clinical study participants administered a pharmaceutical product. An AE did not necessarily have a causal relationship with the study intervention. An SAE was defined as any untoward medical occurrence that, at any dose: resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent disability/incapacity, was a congenital anomaly/birth defect or important medical event.

Time frame: From first dose of IMP until end of follow-up visit (up to Day 28)

Population: Safety analysis population was defined as all randomized participants who received challenge virus and at least 1 dose of IMP.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
RV299Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Adverse Event12 Participants
RV299Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Serious Adverse Event0 Participants
PlaceboNumber of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Adverse Event12 Participants
PlaceboNumber of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Serious Adverse Event0 Participants
Secondary

Number of Participants With AEs Related to Viral Challenge

An Adverse Event was defined as any untoward medical occurrence in clinical study participants administered a pharmaceutical product. An AE did not necessarily have a causal relationship with the study intervention. Number of participants with AEs possibly, probably or definitely related to viral challenge agents were reported by preferred terms in this outcome measure.

Time frame: From viral challenge on Day 0 up to end of follow-up (Day 28)

Population: Safety analysis population was defined as all randomised participants who received challenge virus and at least 1 dose of IMP.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
RV299Number of Participants With AEs Related to Viral ChallengeChest discomfort (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeNausea (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeChest discomfort (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAgeusia (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeChest discomfort (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAbdominal distension (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeChills (Possibly Related)1 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAnosmia (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeChills (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAbdominal distension (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeChills (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeHeadache (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeDyspnoea (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAbdominal distension (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeDyspnoea (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeSyncope (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeDyspnoea (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeDiarrhoea (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeCough (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAgeusia (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeCough (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeDiarrhoea (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeCough (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeSyncope (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeElectrocardiogram T wave abnormal (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeDiarrhoea (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeElectrocardiogram T wave abnormal (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAgeusia (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeElectrocardiogram T wave abnormal (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMouth ulceration (Possibly Related)1 Participants
RV299Number of Participants With AEs Related to Viral ChallengePlatelet count decreased (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeSyncope (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengePlatelet count decreased (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMouth ulceration (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengePlatelet count decreased (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAnosmia (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeTachycardia (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMouth ulceration (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeTachycardia (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeNausea (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeTachycardia (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMalaise (Possibly Related)2 Participants
RV299Number of Participants With AEs Related to Viral ChallengeUpper respiratory tract infection (Possibly Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeHeadache (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeUpper respiratory tract infection (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMalaise (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeUpper respiratory tract infection (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeNausea (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMusculoskeletal pain (Possibly Related)1 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMalaise (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMusculoskeletal pain (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeAnosmia (Probably Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeMusculoskeletal pain (Definitely Related)0 Participants
RV299Number of Participants With AEs Related to Viral ChallengeHeadache (Possibly Related)2 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMusculoskeletal pain (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeHeadache (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeHeadache (Probably Related)1 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeHeadache (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAgeusia (Possibly Related)1 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAgeusia (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAgeusia (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAnosmia (Possibly Related)1 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAnosmia (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAnosmia (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeSyncope (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeSyncope (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeSyncope (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeNausea (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeNausea (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeNausea (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAbdominal distension (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAbdominal distension (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeAbdominal distension (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeDiarrhoea (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeDiarrhoea (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeDiarrhoea (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMouth ulceration (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMouth ulceration (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMouth ulceration (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMalaise (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMalaise (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMalaise (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeChest discomfort (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeChest discomfort (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeChest discomfort (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeChills (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeChills (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeChills (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeDyspnoea (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeDyspnoea (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeDyspnoea (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeCough (Possibly Related)1 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeCough (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeCough (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeElectrocardiogram T wave abnormal (Possibly Related)1 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeElectrocardiogram T wave abnormal (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeElectrocardiogram T wave abnormal (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengePlatelet count decreased (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengePlatelet count decreased (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengePlatelet count decreased (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeTachycardia (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeTachycardia (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeTachycardia (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeUpper respiratory tract infection (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeUpper respiratory tract infection (Probably Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeUpper respiratory tract infection (Definitely Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMusculoskeletal pain (Possibly Related)0 Participants
PlaceboNumber of Participants With AEs Related to Viral ChallengeMusculoskeletal pain (Probably Related)0 Participants
Secondary

Number of Participants With Concomitant Medications

Number of participants with concomitant medications were reported in this outcome measure.

Time frame: From viral challenge on Day 0 up to end of follow-up (Day 28)

Population: Safety analysis population was defined as all randomized participants who received challenge virus and at least 1 dose of IMP.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
RV299Number of Participants With Concomitant Medications17 Participants
PlaceboNumber of Participants With Concomitant Medications16 Participants
Secondary

Overall Peak Total Clinical Symptoms (TSS) Score

Peak total clinical symptoms (TSS) as measured from 10 symptoms within the graded symptom scoring system collected 3 times daily starting from initial administration of IMP up to planned discharge from quarantine. The following types of symptoms were recorded: Upper Respiratory Tract (URT): runny nose, stuffy nose, sore throat, sneezing, earache; Lower Respiratory Tract (LRT): cough, shortness of breath; Systemic: headache, malaise, muscle/joint ache/stiffness. Each symptom was recorded on a grading scale of 0 to 3 (or 0 to 4 for the Shortness of Breath symptom), where higher scores indicated greater severity of symptoms. The total symptom score was calculated as sum of the 10 observed symptom grade values and ranged from 0 to 31, where higher scores indicated more severe symptoms. The overall peak score was defined as the highest scoring symptom diary card observed from the first administration of IMP until quarantine discharge.

Time frame: From initial administration of IMP (before or after administration) up to planned discharge from quarantine (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Overall Peak Total Clinical Symptoms (TSS) Score3.30 Units on a scaleStandard Deviation 2.835
PlaceboOverall Peak Total Clinical Symptoms (TSS) Score3.90 Units on a scaleStandard Deviation 3.063
p-value: 0.20395% CI: [-2.38, 0.52]ANCOVA
Secondary

Peak Viral Load of RSV Determined by qRT-PCR

Peak viral load of RSV as defined by the maximum viral load determined by qRT-PCR measurements in nasal samples starting from initial administration of IMP up to planned discharge from quarantine was reported in this outcome measure.

Time frame: From initial administration of IMP up to planned discharge from quarantine (Up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Peak Viral Load of RSV Determined by qRT-PCR5.01 Log10 copies per milliliterStandard Deviation 1.968
PlaceboPeak Viral Load of RSV Determined by qRT-PCR6.23 Log10 copies per milliliterStandard Deviation 1.735
p-value: 0.004795% CI: [-2.43, -0.47]ANCOVA
Secondary

Peak Viral Load of RSV Determined by Viral Culture

Peak viral load of RSV as defined by the maximum viral load determined by viral culture measurements in nasal samples starting from initial administration of IMP up to planned discharge from quarantine was reported in this outcome measure.

Time frame: From initial administration of IMP up to planned discharge from quarantine (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Peak Viral Load of RSV Determined by Viral Culture2.43 Log10 plaque forming units/mLStandard Deviation 2.03
PlaceboPeak Viral Load of RSV Determined by Viral Culture3.63 Log10 plaque forming units/mLStandard Deviation 2.285
p-value: 0.086595% CI: [-2.13, 0.15]ANCOVA
Secondary

Terminal Half-Life (t1/2) for RV299

Time frame: Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96 hours post-dose 1 and dose 10

Population: PK population consisted of all participants from ITT population (all randomized participants who received challenge virus and at least 1 dose of IMP) with at least one post-dose PK result. Here, 'Number Analyzed' signifies participants evaluable for specified timepoints. t1/2 for dose 1 could not be calculated as at least 3 data points were required in terminal elimination phase within same participant; this criteria could not be fulfilled due to insufficient data above limit of quantification.

ArmMeasureGroupValue (GEOMETRIC_MEAN)Dispersion
RV299Terminal Half-Life (t1/2) for RV299Dose 1NA Hours
RV299Terminal Half-Life (t1/2) for RV299Dose 1012.1 HoursGeometric Coefficient of Variation 6
Secondary

Time to Confirmed Negative Test by qRT-PCR Measurement Starting From Initial Administration of Investigational Medicinal Product (IMP) to First Confirmed Undetectable Assessment After Peak Measure

The time from the first administration of IMP to the first confirmed negative qRT-PCR test after the peak qRT-PCR measurement was calculated as: Date and time of first confirmed negative test after peak qRT-PCR measurement minus Date and time of first IMP administration. A negative test was defined as two consecutive 'Not Detected' results in the qRT-PCR test. The peak qRT-PCR was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants without a confirmed undetectable assessment after their peak, were censored at their last detected qRT-PCR assessment.

Time frame: From first administration of IMP to the first confirmed negative qRT-PCR test or censoring date (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEDIAN)
RV299Time to Confirmed Negative Test by qRT-PCR Measurement Starting From Initial Administration of Investigational Medicinal Product (IMP) to First Confirmed Undetectable Assessment After Peak Measure4.2 Days
PlaceboTime to Confirmed Negative Test by qRT-PCR Measurement Starting From Initial Administration of Investigational Medicinal Product (IMP) to First Confirmed Undetectable Assessment After Peak Measure8.5 Days
p-value: <0.0001Log Rank
Secondary

Time to Confirmed Negative Test by qRT-PCR Measurement Starting From Peak qRT-PCR After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure

The time from the peak qRT-PCR measurement after administration of IMP to the first confirmed negative qRT-PCR test was calculated as (Date and time of first confirmed negative test after peak qRT-PCR measurement minus Date and time of peak qRT-PCR measurement). A negative test was defined as two consecutive 'Not Detected' results in the qRT-PCR test. The peak qRT-PCR was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants without a confirmed undetectable assessment after their peak, were censored at their last detected qRT-PCR assessment.

Time frame: From peak qRT-PCR measurement to the first confirmed negative qRT-PCR test or censoring date (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEDIAN)
RV299Time to Confirmed Negative Test by qRT-PCR Measurement Starting From Peak qRT-PCR After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure2.5 Days
PlaceboTime to Confirmed Negative Test by qRT-PCR Measurement Starting From Peak qRT-PCR After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure5.0 Days
p-value: 0.0051Log Rank
Secondary

Time to Confirmed Negative Test by Viral Culture Measurement Starting From at Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure

Time to confirmed negative test by viral culture measurements in nasal samples from initial administration of IMP up to first confirmed negative viral culture measurement after the peak viral culture measurement was calculated as: Date and time of first confirmed negative test after peak viral culture measurement minus Date and time of first IMP administration. A negative test was defined as two consecutive 'Not Detected' results in the viral culture test. The peak viral culture measurement was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants who did not have a confirmed undetectable assessment after their peak viral culture measurement after first administration of IMP were censored at their last detectable assessment.

Time frame: From initial administration of IMP up to first confirmed undetectable assessment or censoring date (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEDIAN)
RV299Time to Confirmed Negative Test by Viral Culture Measurement Starting From at Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure3.2 Days
PlaceboTime to Confirmed Negative Test by Viral Culture Measurement Starting From at Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure5.0 Days
p-value: 0.0008Log Rank
Secondary

Time to Confirmed Negative Test by Viral Culture Measurement Starting From Peak Viral Culture After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure

The time from the peak viral culture measurement after administration of IMP to the first confirmed negative viral culture measurement was calculated in days as: Date of and time first confirmed negative test minus Date and time of peak qRT-PCR measurement. A negative test was defined as two consecutive 'Not Detected' results in the viral culture test. The peak viral culture measurement was defined as the highest viral load value obtained by a participant after their first administration of IMP. Participants who did not have a confirmed undetectable assessment after their peak viral culture measurement after first administration of IMP were censored at their last detectable assessment.

Time frame: From peak qRT-PCR measurement to first confirmed undetectable assessment or censoring date (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEDIAN)
RV299Time to Confirmed Negative Test by Viral Culture Measurement Starting From Peak Viral Culture After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure1.3 Days
PlaceboTime to Confirmed Negative Test by Viral Culture Measurement Starting From Peak Viral Culture After Initial Administration of IMP to First Confirmed Undetectable Assessment After Peak Measure1.6 Days
p-value: 0.8579Log Rank
Secondary

Time to Maximum Plasma Concentration (Tmax) for RV299

Time frame: Pre-dose, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8,10, 12, 24, 36, 48, 60, 72, 84 and 96-hours post-dose 1 and dose 10

Population: Pharmacokinetic (PK) population consisted of all participants from ITT population (all randomized participants who received challenge virus and at least 1 dose of IMP) with at least one post-dose PK result.

ArmMeasureGroupValue (MEDIAN)
RV299Time to Maximum Plasma Concentration (Tmax) for RV299Dose 12.85 Hours
RV299Time to Maximum Plasma Concentration (Tmax) for RV299Dose 102.45 Hours
Secondary

Time to Peak qRT-PCR Starting From Initial Administration of IMP

The time to the peak qRT-PCR measurement starting from the initial administration of IMP was calculated as: Date and time of peak qRT-PCR measurement minus Date and time of first IMP administration. The peak qRT-PCR was defined as the highest viral load value obtained by a participant after their first administration of IMP.

Time frame: From first administration of IMP to peak qRT-PCR measurement (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEDIAN)
RV299Time to Peak qRT-PCR Starting From Initial Administration of IMP1.5 Days
PlaceboTime to Peak qRT-PCR Starting From Initial Administration of IMP1.5 Days
p-value: 0.0077Log Rank
Secondary

Time to Peak Symptom Score From Initial Administration of IMP

Time to peak as measured from 10 symptoms within the graded daily symptom scoring system starting from initial administration of IMP to the time of peak daily symptom score. If the peak symptom score occurred on more than one day then the first occurrence was selected. Participants were censored at their last assessment if they did not record any symptoms during the quarantine period.

Time frame: From first dose of IMP until time of highest total symptom score or censoring date (Up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEDIAN)
RV299Time to Peak Symptom Score From Initial Administration of IMP1.61 Days
PlaceboTime to Peak Symptom Score From Initial Administration of IMP2.74 Days
Secondary

Time to Symptom Resolution Starting at Initial Administration of IMP to 24 Hours Symptom Free

Symptom resolution was defined as a participant scoring 0 for the total symptom score for a 24-hour period (e.g., a minimum of three consecutive symptom diary cards, each with a score of 0) after their peak symptom score. The time from the assessment at the time of the first administration of IMP until symptom resolution was calculated as: Date and time of symptom resolution minus Date and time of assessment at IMP administration. If the peak symptom score occurred on more than one day then the first occurrence was selected. Participants who did not record 24 hours symptom free after their highest total symptom score during the quarantine period were censored at their last assessment.

Time frame: From first administration of IMP until time of symptom resolution or censoring date (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection. Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

ArmMeasureValue (MEDIAN)
RV299Time to Symptom Resolution Starting at Initial Administration of IMP to 24 Hours Symptom Free3.99 Days
PlaceboTime to Symptom Resolution Starting at Initial Administration of IMP to 24 Hours Symptom Free6.40 Days
Secondary

Time to Symptom Resolution Starting at Peak Symptoms After Initial Administration to 24 Hours Symptom Free

Symptom resolution was defined as a participant scoring 0 for the total symptom score for a 24-hour period (e.g., a minimum of three consecutive symptom diary cards, each with a score of 0) after their peak symptom score. The time from the highest total symptom score following administration of IMP until symptom resolution was calculated as: Date and time of symptom resolution minus Date and time of highest total symptom score. If the peak symptom score occurred on more than one day then the first occurrence was selected. Participants who did not record 24 hours symptom free after their highest total symptom score during the quarantine period were censored at their last assessment.

Time frame: From time of highest total symptom score until time of symptom resolution or censoring date (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection. Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

ArmMeasureValue (MEDIAN)
RV299Time to Symptom Resolution Starting at Peak Symptoms After Initial Administration to 24 Hours Symptom Free1.44 Days
PlaceboTime to Symptom Resolution Starting at Peak Symptoms After Initial Administration to 24 Hours Symptom Free3.67 Days
Secondary

Total Number of Tissues Used by Participants Starting At Initial Administration of IMP up to Planned Discharge From Quarantine

Total number of tissues was counted from the assessment at the time of the first dose of IMP (prior to or after dosing, depending on whether dosed in the morning or evening) to morning of Day 12 (Quarantine discharge).

Time frame: From first administration of IMP up to planned discharge from quarantine (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Total Number of Tissues Used by Participants Starting At Initial Administration of IMP up to Planned Discharge From Quarantine14.09 TissuesStandard Deviation 21.067
PlaceboTotal Number of Tissues Used by Participants Starting At Initial Administration of IMP up to Planned Discharge From Quarantine28.17 TissuesStandard Deviation 33.078
Secondary

Total Weight of Mucus Produced Starting at Initial Administration of IMP up to Planned Discharge From Quarantine

Total weight of nasal mucus was calculated as the sum of mucus weights taken from the assessment at the time of the first administration of IMP (prior to or after dosing, depending on whether dosed in the morning or evening) to morning of Day 12 (Quarantine discharge).

Time frame: From first administration of IMP up to planned discharge from quarantine (up to Day 12)

Population: ITT-I Population consisted of all randomized participants who received challenge virus and at least 1 dose of IMP and met the criterion for RSV infection.

ArmMeasureValue (MEAN)Dispersion
RV299Total Weight of Mucus Produced Starting at Initial Administration of IMP up to Planned Discharge From Quarantine7.49 GramsStandard Deviation 14.516
PlaceboTotal Weight of Mucus Produced Starting at Initial Administration of IMP up to Planned Discharge From Quarantine16.23 GramsStandard Deviation 21.85

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026