A Study of Rilematovir in Infants and Children and Subsequently in Neonates Hospitalized With Acute Respiratory Tract Infection Due to Respiratory Syncytial Virus (RSV)
Condition: Respiratory Tract Infections
MeSH terms: Infections; Communicable Diseases; Respiratory Tract Infections
Intervention: Rilematovir; Rilematovir X mg/kg; Placebo
Intervention description: Participants of age group greater than or equal to (>=) 28 days to less than (<) 3 months (age group 1) or >= 3 months to < 6 months (age group 2) or >= 6 months to less than or equal to (<=) 5 years (age group 3) will receive rilematovir orally twice a day (BID) from Days 1 to Day 7 or Day 8.; Participants of age group birth at term (after at least 37 weeks of gestation) to < 28 days (age group 4) will receive rilematovir orally BID from Days 1 to Day 7 or Day 8. The dose is dependent on outcome of the substudy in neonates and following independent data monitoring (IDMC) review and recommendation.; Participant of age group 1, 2, 3 and 4 will receive matching placebo of rilematovir BID from Days 1 to Day 7 or Day 8 as per assigned age group.
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 28.0
Sex: All
Minimum age: 1 Day
Maximum age: 5 Years
Healthy volunteers: No

Summary:

      The purpose of the study is to evaluate the efficacy of rilematovir compared to placebo
      treatment with respect to the clinical outcome on the RSV Recovery Scale (RRS).
    

Eligibility criteria:

        Inclusion criteria:

          -  The participant weighs within greater than or equal to (>=) 2.4 kilograms (kg) and
             less than or equal to (<=) 24.6 kg

          -  Each participant's parent(s) (preferably both if available or as per local
             requirements) or their legally acceptable representative(s) has/have signed an
             informed consent form (ICF) indicating that (s)he understands the purpose of, and
             procedures required for, the study; is willing for their child to participate in the
             study; with regards to the concomitant medication, the lifestyle consideration and
             study procedures and assessments to be performed by the parent(s)/caregiver(s) as well
             as those by the investigator/study site personnel

          -  The participant has an acute respiratory illness with at least 1 of the signs/symptoms
             within 24 hours prior to start of screening and at screening, as evaluated by the
             investigator in Upper respiratory tract infection: nasal congestion or rhinorrhea; and
             Lower respiratory tract infection: increased respiratory effort (as evidenced by
             subcostal, intercostal or tracheosternal retractions, grunting, head bobbing, nasal
             flaring, or tachypnea), wheezing, cough, cyanosis, or apnea; and systemic/general:
             feeding difficulties (defined as <75 percent [%] intake of normal food amounts);
             dehydration; fever; disturbed sleep, or disturbed activity level
             (irritable/restless/agitated/less responsive). Cough or wheezing cannot be the only
             LRTI sign/symptom present, that is, at least one other LRTI sign/symptom needs to be
             present for eligibility

          -  The time of onset of RSV signs/symptoms to the anticipated time of randomization must
             be less than or equal to (<=) 3 days. Onset of signs/symptoms is defined as the time
             of the day (or part of the day if time of the day cannot be specified) the
             parent(s)/caregiver(s) became aware of the first sign and/or symptom consistent with
             respiratory or systemic/general manifestation of signs/symptoms of RSV infection. The
             time of sign/symptom onset has to be assessed as accurately as possible

          -  Participants are otherwise healthy or have (a) risk factor(s) for severe RSV disease

        Exclusion criteria:

          -  The participant has had either confirmed severe acute respiratory syndrome
             coronavirus-2 (SARS-CoV-2) infection (test positive) during the four weeks prior to
             randomization, or close contact with a person with COVID-19 (test confirmed or
             suspected SARS CoV-2 infection) within 14 days prior to randomization

          -  Confirmed QT interval corrected for heart rate according to Fridericia's formula
             (QTcF) interval greater than (>) 450 milliseconds (msec) per the machine read
             parameter result at screening. Presence of an abnormal QTcF interval should be
             confirmed by repeat electrocardiogram (ECG) recording during screening

          -  Known personal or family history of Long QT Syndrome or sudden cardiac death

          -  Presence of repetitive ventricular premature contractions (>10/minutes [min]), second-
             or third-degree heart block, or complete or incomplete left bundle branch block, or
             complete right bundle branch block per the machine read ECG result at screening.
             Presence of any of the above abnormalities should be confirmed by repeat ECG recording
             during screening