Phase 3
N=3,632
Efficacy and Safety of Clesrovimab (MK-1654) in Infants (MK-1654-004)
Respiratory Syncytial Virus Infection
Bottom Line
View on ClinicalTrials.gov: NCT04767373 ↗Enrolled (actual)
3,632
Serious AEs
9.5%
Results posted
Feb 2025
Primary outcome: Primary: RSV Season 1: Number of Participants With Respiratory Syncytial Virus (RSV)-Associated Medically Attended Lower Respiratory Infection (MALRI) — 60; 74 Participants — p=<0.001
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- Clesrovimab (Biological); Placebo (Drug)
- Age
- Pediatric
- Sex
- All
- Sponsor
- Merck Sharp & Dohme LLC
- Primary completion
- Jul 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY RSV Season 1: Number of Participants With Respiratory Syncytial Virus (RSV)-Associated Medically Attended Lower Respiratory Infection (MALRI) |
60; 74 | <0.001 sig |
| PRIMARY RSV Season 1: Percentage of Participants With Solicited Injection-Site Adverse Events (AEs) |
11.4; 11.7 | — |
| PRIMARY RSV Season 1: Percentage of Participants With Fever |
0.5; 1.2 | — |
| PRIMARY RSV Season 1: Percentage of Participants With Solicited Systemic AEs |
30.1; 31.2 | — |
| PRIMARY RSV Season 1: Percentage of Participants With Anaphylaxis/Hypersensitivity AE of Special Interest (AESI) |
0.0; 0.0 | — |
| PRIMARY RSV Season 1: Percentage of Participants With Rash AESI |
0.5; 0.3 | — |
| PRIMARY RSV Season 1: Percentage of Participants With ≥1 Nonserious AE |
74.8; 75.5 | — |
| PRIMARY Percentage of Participants With Serious Adverse Events (SAEs) |
11.7; 12.6; 3.1; 4.0 | — |
| SECONDARY RSV Season 1: Number of Participants With RSV-Associated Hospitalization |
9; 28 | <0.001 sig |
| SECONDARY RSV Season 1: Number of Participants With RSV-Associated MALRI |
64; 77 | — |
Summary
The primary objectives of this phase 2b/3 double-blind, randomized, placebo-controlled study are to evaluate the efficacy and safety of clesrovimab in healthy pre-term and full-term infants. It is hypothesized that clesrovimab will reduce the incidence of respiratory syncytial virus (RSV)-associated medically attended lower respiratory infection (MALRI) from Days 1 through 150 postdose compared to placebo.
Eligibility Criteria
Key Inclusion Criteria
- Is a healthy male or female who is an early or moderate pre-term infant (≥29 to 34 weeks and 6 days gestational age) or a late pre-term or full-term infant (≥35 weeks gestational age)
- For the phase 2b cohort only: Has a chronological age >2 weeks of age up to 1 year and is entering their first respiratory syncytial virus (RSV) season at the time of obtaining documented informed consent.
- For the phase 3 cohort only: Has a chronological age from birth up to 1 year and is entering their first RSV season at the time of obtaining documented informed consent.
- For participants in South Korea only: Weighs ≥2 kg
Key Exclusion Criteria
- Is recommended to receive palivizumab per local guidelines or professional society recommendations.
- Has known hypersensitivity to any component of clesrovimab
- Has a bleeding disorder contraindicating IM administration
- Has had a recent illness with rectal temperature ≥100.5°F (≥38.1°C) or axillary temperature ≥100.0°F (≥37.8°C) within 72 hours predose
- Has received any vaccine or monoclonal antibody for the prevention of RSV
- Is currently participating in or has participated in an interventional clinical study with an investigational compound or device at any time before first dose administration or while participating in this study
Data sourced from ClinicalTrials.gov (NCT04767373). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.