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Monoclonal Antibodies

Clesrovimab for Respiratory Syncytial Virus

Phase 2 & 3
Waitlist Available
Research Sponsored by Merck Sharp & Dohme Corp.
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
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.
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)
Must not have
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
Timeline
Screening 3 weeks
Treatment Varies
Follow Up from day 1 (postdose) to day 180

Summary

This trial is testing a medication called clesrovimab in healthy pre-term and full-term infants. The goal is to see if it can prevent serious lung infections caused by the RSV virus. Clesrovimab works by helping the immune system fight off the virus more effectively.

Who is the study for?
This trial is for healthy pre-term and full-term infants up to 1 year old, entering their first RSV season. It includes early or moderate pre-term infants (≥29 weeks) and excludes those with hypersensitivity to clesrovimab, bleeding disorders, recent high fever, prior RSV vaccines or treatments, or involvement in other drug/device trials.
What is being tested?
The study tests the effectiveness of Clesrovimab against a placebo in preventing medically attended lower respiratory infections caused by RSV in infants. This phase 2b/3 trial randomly assigns participants to receive either the medication or a placebo.
What are the potential side effects?
While specific side effects are not listed here, potential risks may include reactions at the injection site, allergic responses due to sensitivity to clesrovimab's components, and general side effects typically monitored in infant clinical trials.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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My child is under 1 year old and facing their first RSV season.
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I am a healthy infant born between 29 weeks and full-term.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
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I have a bleeding disorder that prevents me from getting shots in my muscles.
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I have had a fever of 100.5°F or higher in the last 3 days.
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I have received a vaccine or antibody for RSV prevention.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~from day 1 (postdose) to day 180
This trial's timeline: 3 weeks for screening, Varies for treatment, and from day 1 (postdose) to day 180 for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Percentage of participants with anaphylaxis/hypersensitivity AE of special interest (AESI)
Percentage of participants with fever
Percentage of participants with rash AESI
+4 more
Secondary study objectives
Percentage of participants with RSV-associated MALRI
Percentage of participants with RSV-associated hospitalization

Side effects data

From 2020 Phase 2 trial • 80 Patients • NCT04086472
38%
Headache
13%
Odynophagia
13%
Rhinorrhoea
6%
Nausea
6%
Upper respiratory tract infection
6%
Nasal injury
6%
C-reactive protein increased
6%
Musculoskeletal pain
6%
Cough
6%
Phlebitis
6%
Neck pain
6%
Oropharyngeal pain
6%
Contusion
6%
Epistaxis
6%
Gastroenteritis
6%
Oral herpes
100%
80%
60%
40%
20%
0%
Study treatment Arm
MK-1654 100 mg
MK-1654 300 mg
MK-1654 200 mg
MK-1654 900 mg
Placebo

Trial Design

2Treatment groups
Experimental Treatment
Placebo Group
Group I: ClesrovimabExperimental Treatment1 Intervention
Participants receive a single intramuscular (IM) administration of clesrovimab on Day 1.
Group II: PlaceboPlacebo Group1 Intervention
Participants receive a single IM administration of placebo on Day 1.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
Clesrovimab
2019
Completed Phase 3
~3900

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.
Mechanism Of Action
Side Effect Profile
Prior Approvals
Other Research
The most common treatments for Respiratory Syncytial Virus (RSV) primarily include supportive care, as there are no curative therapies currently available. However, monoclonal antibodies, such as Clesrovimab, are being studied for their potential to reduce the incidence of RSV-associated lower respiratory infections. These antibodies work by targeting specific proteins on the RSV virus, neutralizing its ability to infect host cells and thereby reducing the severity and duration of the infection. Understanding these mechanisms is crucial for RSV patients because it offers a targeted approach to prevent severe respiratory complications, potentially reducing hospitalizations and improving overall outcomes.
New therapies for acute RSV infections: where are we?

Find a Location

Who is running the clinical trial?

Merck Sharp & Dohme Corp.Lead Sponsor
2,286 Previous Clinical Trials
4,578,864 Total Patients Enrolled
Merck Sharp & Dohme LLCLead Sponsor
4,000 Previous Clinical Trials
5,178,200 Total Patients Enrolled
Medical DirectorStudy DirectorMerck Sharp & Dohme LLC
2,880 Previous Clinical Trials
8,081,488 Total Patients Enrolled

Media Library

Clesrovimab (Monoclonal Antibodies) Clinical Trial Eligibility Overview. Trial Name: NCT04767373 — Phase 2 & 3
Respiratory Syncytial Virus Research Study Groups: Clesrovimab, Placebo
Respiratory Syncytial Virus Clinical Trial 2023: Clesrovimab Highlights & Side Effects. Trial Name: NCT04767373 — Phase 2 & 3
Clesrovimab (Monoclonal Antibodies) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04767373 — Phase 2 & 3
Respiratory Syncytial Virus Patient Testimony for trial: Trial Name: NCT04767373 — Phase 2 & 3
~807 spots leftby Nov 2025