COVID-19Phase 2NCT04992273
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
A Phase 2 study testing casirivimab+imdevimab in people with COVID-19, run by Regeneron Pharmaceuticals at 7 sites in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 1 minute to 12 years
- Conditions the study is for
- COVID-19
- What is being tested?
- casirivimab+imdevimab
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 7 participants
- Where
- 7 sitesUnited States
- Study dates
- 13 Sep 2021to 1 Jun 2022
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 minute to 12 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Is <12 years of age and ≥3 kg to <40 kg at the time parental/guardian consent is signed
- Has at least one risk factor for developing severe COVID-19 if they were to become infected, such as:
- Obesity (BMI [kg/m2] ≥95th percentile for age and sex based on CDC growth charts)
- Cardiovascular disease
- Chronic lung disease
- Type 1 or type 2 diabetes mellitus
Show all 11Show fewer
- Chronic kidney disease, including those on dialysis
- Chronic liver disease
- 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)
- Medical complexities (examples include any underlying genetic condition, neurologic condition, metabolic condition, or congenital heart disease)
- Any other condition deemed by the Investigator to be a risk factor for severe COVID-19
Who cannot join
- 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.
- Has active respiratory or non-respiratory symptoms consistent with COVID-19 in the opinion of the Investigator
- Has subject-reported clinical history of COVID-19, as determined by Investigator, within the last 90 days
- Has subject-reported history of prior Emergency Use Authorization (EUA)/approved positive diagnostic test for SARSCoV-2 infection within the last 90 days
- Is currently hospitalized or was hospitalized for >24 hours for any reason within 14 days of the screening visit
- 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)
Show all 9Show fewer
- 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.
- 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
Trial locations and contacts
7 sites in 1 country.
7 sites in 1 country
United States7 sites
Advanced Research Center, Inc
Anaheim, California, 92805
Coastal Pediatric Research
Charleston, South Carolina, 29414
Batchelor's Children's Research Institute
Miami, Florida, 33136
Regeneron Research Site
Richmond, Virginia, 23226
Stony Brook University Hospital
Stony Brook, New York, 11794
SUNY Upstate Medical University
Syracuse, New York, 13210
Jacobi Medical Center
The Bronx, New York, 10461
About this study
Official title: 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
- Conditions
- COVID-19
- Being tested
- casirivimab+imdevimab
- Keywords
- Coronavirus disease 2019 (COVID-19), Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), coronavirus
- Medical subject headings
- COVID-19, Coronavirus Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
casirivimab+imdevimabDrug
Also called REGN10933-10987, REGN-COV2, REGEN-COV™, RONAPREVE™
Single dose administered based on weight
| Study group | Role | What they receive |
|---|---|---|
| ≥20 kg to <40 kg | Experimental | SC administration Receives: Drug: casirivimab+imdevimab |
| ≥10 kg to <20 kg | Experimental | SC administration Receives: Drug: casirivimab+imdevimab |
| ≥5 kg to <10 kg | Experimental | SC administration Receives: Drug: casirivimab+imdevimab |
| ≥3 kg to <5 kg | Experimental | SC administration Receives: Drug: casirivimab+imdevimab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Concentrations of Casirivimab+Imdevimab in Serum Over Time.
Concentrations reported in milligrams per Liter (mg/L)
Measured: Day 0 and Day 14
Secondary outcomes (8)
Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
Measured: Through end of study, approximately 24 weeks
Number of Participants With Indicated Severity of TEAEs
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.
Measured: Through end of study, approximately 24 weeks
Number of Participants With Grade ≥3 Injection Site Reactions
Measured: Through Day 4
Number of Participants With Grade ≥3 Hypersensitivity Reactions
Measured: Through Day 4
Number of Participants With Indicated Immunogenicity as Measured by Anti-drug Antibodies (ADA) to Casirivimab Over Time
Measured: Up to 24 weeks
Number of Participants With Indicated Immunogenicity as Measured by ADA to Imdevimab Over Time
Measured: Up to 24 weeks
Immunogenicity as Measured by Neutralizing Antibodies (NAb) to Casirivimab Over Time
Measured: Up to 24 weeks
Immunogenicity as Measured by NAb to Imdevimab Over Time
Measured: Up to 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2021
- Study start13 Sep 2021
- Primary completion1 Jun 2022
- Study completion1 Jun 2022
Why it stopped: Emerging SARS-CoV-2 variants impacting susceptibility to study drug
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by Regeneron PharmaceuticalsThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 7 participants (actual)
Sponsor and investigators
- Lead sponsor
- Regeneron Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Clinical Trial Management, Study director, Regeneron Pharmaceuticals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04992273
- Sponsor's protocol ID
- R10933-10987-COV-2121
- Other IDs
- 2021-004590-30
- Status last verified
- Oct 2025
- First submitted
- 3 Aug 2021
- Last updated
- 20 Oct 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT04992273
- Acronym / sponsor ID
- R10933-10987-COV-2121
- Conditions
- COVID-19
- Keywords
- Coronavirus disease 2019 (COVID-19), Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), coronavirus
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Emerging SARS-CoV-2 variants impacting susceptibility to study drug
- Enrolment
- 7 participants (actual)
- Lead sponsor
- Regeneron PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 13 Sep 2021 (actual)
- Primary completion
- 1 Jun 2022 (actual)
- Study completion
- 1 Jun 2022 (actual)
- First posted
- 5 Aug 2021 (actual)
- Results
- Posted 6 Mar 2023
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| ≥20 kg to <40 kg | Experimental | Drug: casirivimab+imdevimabSC administration |
| ≥10 kg to <20 kg | Experimental | Drug: casirivimab+imdevimabSC administration |
| ≥5 kg to <10 kg | Experimental | Drug: casirivimab+imdevimabSC administration |
| ≥3 kg to <5 kg | Experimental | Drug: casirivimab+imdevimabSC administration |
Who may qualify
- Ages
- 1 minute to 12 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (11 listed)
- Is <12 years of age and ≥3 kg to <40 kg at the time parental/guardian consent is signed
- Has at least one risk factor for developing severe COVID-19 if they were to become infected, such as:
Key exclusion criteria (9 listed)
- 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.
- Has active respiratory or non-respiratory symptoms consistent with COVID-19 in the opinion of the Investigator
- Has subject-reported clinical history of COVID-19, as determined by Investigator, within the last 90 days
- Has subject-reported history of prior Emergency Use Authorization (EUA)/approved positive diagnostic test for SARSCoV-2 infection within the last 90 days
- Is currently hospitalized or was hospitalized for >24 hours for any reason within 14 days of the screening visit
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| casirivimab+imdevimabAlso: REGN10933-10987, REGN-COV2, REGEN-COV™, RONAPREVE™Single dose administered based on weight | Drug | ≥10 kg to <20 kg, ≥20 kg to <40 kg, ≥3 kg to <5 kg, ≥5 kg to <10 kg |
Primary outcome
Concentrations of Casirivimab+Imdevimab in Serum Over Time.
Time frame: Day 0 and Day 14
Concentrations reported in milligrams per Liter (mg/L)
8 secondary outcomes
Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
Time frame: Through end of study, approximately 24 weeks
Number of Participants With Indicated Severity of TEAEs
Time frame: Through end of study, approximately 24 weeks
Number of Participants With Grade ≥3 Injection Site Reactions
Time frame: Through Day 4
Number of Participants With Grade ≥3 Hypersensitivity Reactions
Time frame: 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
Number of Participants With Indicated Immunogenicity as Measured by ADA to Imdevimab Over Time
Time frame: Up to 24 weeks
Immunogenicity as Measured by Neutralizing Antibodies (NAb) to Casirivimab Over Time
Time frame: Up to 24 weeks
Immunogenicity as Measured by NAb to Imdevimab Over Time
Time frame: Up to 24 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Related trials for COVID-19
Not yet recruitingPhase 1
Phase I Open-Label Safety Trial of Pembrolizumab for Neurological Post- Acute Sequelae of SARS-CoV-2 (PD1-PASC I)
Post-Acute COVID-19 Syndrome
Active, not recruitingPhase 1
A Safety and Immunogenicity Trial of OCU500, ChAd36 Vector Encoding SARS-CoV-2 Spike Vaccine Via Intranasal and Inhalational Routes in Previously Vaccinated Adults
COVID-19
Active, not recruiting
Intervention to Address Disparate Mental Health Consequences of COVID-19 Pandemic on Latinx and African Newcomers
Mental Health Issue, Mental Health Disorder
Recruiting
Home-Based Exercise Tele-Rehabilitation After COVID-19
Post SARS-CoV2 (COVID-19)
Not yet recruitingPhase 1
A Safety, Reactogenicity and Immunogenicity Trial of RVX-sCPD9 Booster Intranasal COVID-19 Vaccine
COVID -19
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Clinical Trial Management study director
Regeneron Pharmaceuticals
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing casirivimab+imdevimab in people with COVID-19, run by Regeneron Pharmaceuticals at 7 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 20 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 6 Mar 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Concentrations of Casirivimab+Imdevimab in Serum Over Time. (time frame: Day 0 and Day 14). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2025.