COVID-19 Administration of Single-Dose Subcutaneous Anti- Spike(s) SARS-CoV-2 Monoclonal Antibodies Casirivimab and Imdevimab in High-Risk Pediatric Participants Under 12 Years of Age

October 9, 2025 updated by: Regeneron Pharmaceuticals

A Phase 2A, Open-Label Study Assessing Pharmacokinetics, Safety, Tolerability, and Immunogenicity of Single-Dose Subcutaneous Anti- Spike(s) SARS-COV-2 Monoclonal Antibodies (Casirivimab and Imdevimab) in High-Risk Pediatric Subjects Under 12 Years of Age

The primary objective of the study is to characterize the concentrations of casirivimab+imdevimab in serum over time after a single subcutaneous (SC) administration

The secondary objectives of the study are:

  • To assess the safety and tolerability of SC or single administration of casirivimab+imdevimab
  • To assess the occurrence of grade ≥3 injection site reactions and grade ≥3 hypersensitivity reactions, in participants treated with SC doses of casirivimab+imdevimab
  • To assess the immunogenicity of casirivimab+imdevimab

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
7

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Anaheim, California, United States, 92805
        • Advanced Research Center, Inc
    • Florida
      • Miami, Florida, United States, 33136
        • Batchelor's Children's Research Institute
    • New York
      • Stony Brook, New York, United States, 11794
        • Stony Brook University Hospital
      • Syracuse, New York, United States, 13210
        • SUNY Upstate Medical University
      • The Bronx, New York, United States, 10461
        • Jacobi Medical Center
    • South Carolina
      • Charleston, South Carolina, United States, 29414
        • Coastal Pediatric Research
    • Virginia
      • Richmond, Virginia, United States, 23226
        • Regeneron Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

1 minute to 12 years (Child)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. Is <12 years of age and ≥3 kg to <40 kg at the time parental/guardian consent is signed

  2. Has at least one risk factor for developing severe COVID-19 if they were to become infected, such as:

    1. Obesity (BMI [kg/m2] ≥95th percentile for age and sex based on CDC growth charts)
    2. Cardiovascular disease
    3. Chronic lung disease
    4. Type 1 or type 2 diabetes mellitus
    5. Chronic kidney disease, including those on dialysis
    6. Chronic liver disease
    7. Immunocompromised or immunodeficient, based on Investigator's assessment (examples include cancer treatment, bone marrow or organ transplantation, immune deficiencies, HIV infection, sickle cell anemia, thalassemia, and prolonged use of immune-weakening medications)
    8. Medical complexities (examples include any underlying genetic condition, neurologic condition, metabolic condition, or congenital heart disease)
    9. Any other condition deemed by the Investigator to be a risk factor for severe COVID-19

Key Exclusion Criteria:

  1. Has positive diagnostic test for SARS-CoV-2 infection from a sample collected during screening ≤7 days prior to study drug administration Note: The sample for the test should be collected ≤7 days within study drug administration, and the result should be reviewed and confirmed negative prior to dosing. Historical records will not be accepted.
  2. Has active respiratory or non-respiratory symptoms consistent with COVID-19 in the opinion of the Investigator
  3. Has subject-reported clinical history of COVID-19, as determined by Investigator, within the last 90 days
  4. Has subject-reported history of prior Emergency Use Authorization (EUA)/approved positive diagnostic test for SARSCoV-2 infection within the last 90 days
  5. Is currently hospitalized or was hospitalized for >24 hours for any reason within 14 days of the screening visit
  6. Prior use (within 90 days prior to study drug administration) or current use of any investigational, authorized, or approved passive antibody for prophylaxis of SARS-CoV-2 infection, including convalescent plasma, convalescent sera, hyperimmune globulin, or other monoclonal antibodies (eg, bamlanivimab and etesevimab, sotrovimab)
  7. Has initiated vaccination for SARS-CoV-2 with an investigational or approved vaccine, but has not completed the vaccine schedule as recommended by the vaccine manufacturer.
  8. Plans to receive an investigational or approved SARS-CoV-2 vaccine within 90 days after study drug administration, or per the recommended time frame from the current Centers for Disease Control vaccination guidelines (CDC, 2021b)

NOTE: Other protocol-defined Inclusion/ Exclusion Criteria apply

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: ≥20 kg to <40 kg
SC administration
Drug: casirivimab+imdevimab
Single dose administered based on weight
Other Names:
  • REGN-COV2
  • REGEN-COV™
  • REGN10933-10987
  • RONAPREVE™
Experimental: ≥10 kg to <20 kg
SC administration
Drug: casirivimab+imdevimab
Single dose administered based on weight
Other Names:
  • REGN-COV2
  • REGEN-COV™
  • REGN10933-10987
  • RONAPREVE™
Experimental: ≥5 kg to <10 kg
SC administration
Drug: casirivimab+imdevimab
Single dose administered based on weight
Other Names:
  • REGN-COV2
  • REGEN-COV™
  • REGN10933-10987
  • RONAPREVE™
Experimental: ≥3 kg to <5 kg
SC administration
Drug: casirivimab+imdevimab
Single dose administered based on weight
Other Names:
  • REGN-COV2
  • REGEN-COV™
  • REGN10933-10987
  • RONAPREVE™

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Concentrations of Casirivimab+Imdevimab in Serum Over Time.
Time Frame: Day 0 and Day 14
Concentrations reported in milligrams per Liter (mg/L)
Day 0 and Day 14

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
Time Frame: Through end of study, approximately 24 weeks
Through end of study, approximately 24 weeks
Number of Participants With Indicated Severity of TEAEs
Time Frame: Through end of study, approximately 24 weeks
Treatment-emergent adverse events (TEAEs) are defined as those that are not present at baseline or represent the exacerbation of a pre-existing condition during the on-treatment period. The severity of AEs were graded using version 5.0 of NCI-CTCAE.
Through end of study, approximately 24 weeks
Number of Participants With Grade ≥3 Injection Site Reactions
Time Frame: Through Day 4
Through Day 4
Number of Participants With Grade ≥3 Hypersensitivity Reactions
Time Frame: Through Day 4
Through Day 4
Number of Participants With Indicated Immunogenicity as Measured by Anti-drug Antibodies (ADA) to Casirivimab Over Time
Time Frame: Up to 24 weeks
Up to 24 weeks
Number of Participants With Indicated Immunogenicity as Measured by ADA to Imdevimab Over Time
Time Frame: Up to 24 weeks
Up to 24 weeks
Immunogenicity as Measured by Neutralizing Antibodies (NAb) to Casirivimab Over Time
Time Frame: Up to 24 weeks
Up to 24 weeks
Immunogenicity as Measured by NAb to Imdevimab Over Time
Time Frame: Up to 24 weeks
Up to 24 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Regeneron Pharmaceuticals

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Clinical Trial Management, Regeneron Pharmaceuticals

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 13, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 3, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 3, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 5, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 20, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 9, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • R10933-10987-COV-2121
  • 2021-004590-30 (EudraCT Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing

IPD Sharing Time Frame

When Regeneron has received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication, has made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry), has the legal authority to share the data, and has ensured the ability to protect participant privacy.

IPD Sharing Access Criteria

Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Drug Interventions

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