A Study to Learn About the Amount of the Study Medicine (Sisunatovir) in Blood and Its Safety in Infants and Children With Pneumonia Caused by RSV

AN INTERVENTIONAL, PHASE 1b, RANDOMIZED, DOUBLE-BLIND, SPONSOR-OPEN, PLACEBO-CONTROLLED, MULTI-CENTER, DOSE-FINDING STUDY TO EVALUATE SAFETY, TOLERABILITY AND PHARMACOKINETICS OF SISUNATOVIR IN PEDIATRIC PARTICIPANTS UP TO AGE 60 MONTHS WITH RESPIRATORY SYNCYTIAL VIRUS (RSV) LOWER RESPIRATORY TRACT INFECTION (LRTI)

Status

Terminated

Phases

Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06102174

Enrollment

Registered

2023-10-26

Start date

2024-02-15

Completion date

2024-09-03

Last updated

2025-12-30

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

Conditions

Respiratory Syncytial Virus Infections

Keywords

Lower Respiratory Tract Infection

Brief summary

The purpose of the study is to learn about the safety and amount of sisunatovir in the blood of infants and children up to age 60 months. These children have Lower Respiratory Tract Infection (LRTI) caused by Respiratory Syncytial Virus (RSV). LRTI is the infection to the lower airways such as lungs. This study will help inform the amount of sisunatovir to be used in future studies of sisunatovir in children. This study is seeking for participants who: * Are 1 day to less than or equal to 60 months of age * weigh more than or equal to 2.5 kilograms to less than or equal to 23 kilograms. * Have been tested to have RSV by medical tests. * show signs of LRTI. All participants in the study will receive many amounts of sisunatovir or placebo. Placebo is a pill that does not have any medicine in it. Up to 7 visits are required for the study. Some of these visits include checking participants health over the phone and/or a visit at home. The study will compare the experiences of infants and children receiving sisunatovir to identify the amount of sisunatovir to be used in future studies in infants and children.

Interventions

DRUGPlacebo

Placebo

DRUGActive

Sisunatovir

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

OTHER

Masking

TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender

ALL

Age

1 Days to 60 Months

Healthy volunteers

Inclusion criteria

* 1 day to ≤60 months of age and weight ≥2.5 kg to ≤23 kg * Positive RSV diagnostic test, antigen or molecular test * Evidence of Lower Respiratory Tract Infection (LRTI)

Exclusion criteria

* Premature infants (gestational age less than 35 weeks) AND \<1 year of post-natal age * Neonates with intrauterine growth restriction * Expected to receive an antiviral for another viral infection within 10 days of screening * Suspected or confirmed clinically significant moderate or severe bacterial infection that may interfere with the evaluation of response to the study intervention * Known to have significant comorbidities that would limit the ability to administer the study intervention or evaluate the safety or clinical response to the study intervention

Design outcomes

Primary

Measure	Time frame	Description
Number of Participants With Treatment Emergent Adverse Events (TEAEs)	From start of study intervention on Day 1 up to 28 days after last dose of study intervention (maximum up to 33 days)	An adverse event (AE) was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE was considered a TEAE if the event started during the effective duration of treatment. All events that start on or after the first dose of study intervention, but before the end of the study were flagged as TEAEs. All AEs were included for evaluation.
Number of Participants Who Discontinued From Study Due to TEAEs	From start of study intervention on Day 1 up to 28 days after last dose of study intervention (maximum up to 33 days)	An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE was considered a TEAE if the event started during the effective duration of treatment. All events that start on or after the first dose of study intervention, but before the end of the study were flagged as TEAEs.
Number of Participants Who Discontinued From Study Due to Serious TEAEs	From start of study intervention on Day 1 up to 28 days after last dose of study intervention (maximum up to 33 days)	An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE was considered a TEAE if the event started during the effective duration of treatment. All events that start on or after the first dose of study intervention, but before the end of the study were flagged as TEAEs. A serious AE (SAE) was any untoward medical occurrence at any dose that: resulted in death; was life-threatening experience (immediate risk of death); required inpatient hospitalization or prolongation if existing hospitalization; resulted in persistent or significant disability/ incapacity; resulted in congenital anomaly/birth defect; other important event or situation as pre-specified in protocol.
Number of Participants With Clinically Significant Laboratory Abnormalities	From start of study intervention on Day 1 up to 28 days after last dose of study intervention (maximum up to 33 days)	Following parameters were analyzed for laboratory examination: hematology (hemoglobin, hematocrit, red blood cell count, platelet count, white blood cell count, mean cell volume, mean cell hemoglobin & concentration); chemistry: urea and creatinine, estimated glomerular filtration rate (eGFR), gamma-glutamyl transferase (GGT), calcium, sodium, potassium, chloride, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, alkaline phosphatase, albumin, total protein, cystatin C; urinalysis: pH, glucose, protein, blood, ketones, nitrites, leukocyte esterase, albumin, creatinine (urine), urine albumin to creatinine ratio. Clinically significant laboratory abnormalities findings were based on investigator discretion.
Number of Participants With Clinically Significant Vital Signs	From start of study intervention on Day 1 up to 28 days after last dose of study intervention (maximum up to 33 days)	Vital signs included systolic and diastolic blood pressure, pulse rate/heart rate, temperature, respiratory rate, and oxygen saturation. Clinically significance vital signs findings were based on investigator discretion.

Secondary

Measure	Time frame
Plasma Concentrations Versus Time Summary of Sisunatovir	Day 3: Pre-dose, T1 and T2 hours post-dose; Day 5: Pre-dose; where T1 is the first analysis time point post-dose while T2 is the second analysis time point post-dose

Countries

Japan, South Africa, United States

Participant flow

Recruitment details

As per plan study was to have 3 cohorts: 1, 2, and 3. Cohorts 1 and 2 was to have further 4 sub-cohorts: A, B, C and D; and Cohort 3 to have sub-cohorts: B, D, E and F. However, due to early termination of study participants were enrolled only in Cohorts 1A, 1B and 1C. No participants were enrolled in Cohort 1D, Cohort 2, and in Cohort 3; hence no results are reported for them. All results are only pertaining to Cohorts 1A, 1B and 1C in this record.

Pre-assignment details

In this study, participants aged from 1 day to \<=60 months received study intervention. Participants of Cohort 1A received study intervention at a low dose level and participants of Cohorts 1B and 1C received study treatment at high dose levels. Cohort 1A had participants of age category 1 (the lowest age category), cohort 1B had participants of age category 2 (medium age category) and cohort 1C had participants of age category 3 (the highest age category).

Participants by arm

Arm	Count
Cohort 1A: Sisunatovir Participants of age category 1 were randomized and sisunatovir was administered at low dose level orally or via nasogastric tube for 5 days.	1
Cohort 1A: Placebo Participants of age category 1 were randomized and placebo matched to sisunatovir was administered orally or via nasogastric tube for 5 days.	1
Cohort 1B: Sisunatovir Participants of age category 2 were randomized and sisunatovir was administered at high dose level orally or via nasogastric tube for 5 days.	2
Cohort 1B: Placebo Participants of age category 2 were randomized and placebo matched to sisunatovir was administered orally or via nasogastric tube for 5 days.	1
Cohort 1C: Sisunatovir Participants of age category 3 were randomized and sisunatovir was administered at high dose level orally or via nasogastric tube for 5 days.	3
Cohort 1C: Placebo Participants of age category 3 were randomized and placebo matched to sisunatovir was administered orally or via nasogastric tube for 5 days.	2
Total	10

Baseline characteristics

Characteristic	Cohort 1A: Sisunatovir	Cohort 1A: Placebo	Cohort 1B: Sisunatovir	Cohort 1B: Placebo	Cohort 1C: Sisunatovir	Cohort 1C: Placebo	Total
Age, Categorical <=18 years	1 Participants	1 Participants	2 Participants	1 Participants	3 Participants	2 Participants	10 Participants
Age, Categorical >=65 years	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Age, Categorical Between 18 and 65 years	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants	0 Participants	0 Participants	0 Participants	1 Participants	0 Participants	1 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	1 Participants	1 Participants	2 Participants	1 Participants	2 Participants	2 Participants	9 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Asian	0 Participants	1 Participants	2 Participants	1 Participants	2 Participants	2 Participants	8 Participants
Race (NIH/OMB) Black or African American	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) More than one race	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants	0 Participants	0 Participants	0 Participants	1 Participants	0 Participants	1 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) White	1 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	1 Participants
Sex: Female, Male Female	1 Participants	0 Participants	1 Participants	0 Participants	1 Participants	2 Participants	5 Participants
Sex: Female, Male Male	0 Participants	1 Participants	1 Participants	1 Participants	2 Participants	0 Participants	5 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk	EG003 affected / at risk	EG004 affected / at risk	EG005 affected / at risk
deaths Total, all-cause mortality	0 / 1	0 / 1	0 / 2	0 / 1	0 / 3	0 / 2
other Total, other adverse events	0 / 1	1 / 1	1 / 2	1 / 1	3 / 3	1 / 2
serious Total, serious adverse events	0 / 1	0 / 1	0 / 2	0 / 1	0 / 3	0 / 2

Outcome results

Primary

Number of Participants Who Discontinued From Study Due to Serious TEAEs

An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE was considered a TEAE if the event started during the effective duration of treatment. All events that start on or after the first dose of study intervention, but before the end of the study were flagged as TEAEs. A serious AE (SAE) was any untoward medical occurrence at any dose that: resulted in death; was life-threatening experience (immediate risk of death); required inpatient hospitalization or prolongation if existing hospitalization; resulted in persistent or significant disability/ incapacity; resulted in congenital anomaly/birth defect; other important event or situation as pre-specified in protocol.