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OpenTrials
Completed

NCT Number: NCT04852978

COVID-19 Study to Assess Immunogenicity, Safety, and Tolerability of Moderna mRNA-1273 Vaccine Administered With Casirivimab+Imdevimab in Healthy Adult Volunteers

The primary objectives of the study are:

* To evaluate the extent of effect, if any, of REGN10933+REGN10987 administration on vaccine-induced neutralizing antibody responses to SARS-CoV-2 by Moderna mRNA-1273 * To evaluate the time interval required between REGN10933+REGN10987 administration and Moderna mRNA-1273 vaccination, to ensure no meaningful impact on vaccine-induced neutralizing antibody responses to SARS-CoV-2

The secondary objectives of the study are:

* To quantify the alteration of antigen specificity of vaccine-induced SARS-CoV-2 antibody responses when administered with different dose regimens of REGN10933+REGN10987 * To evaluate the safety and tolerability of REGN10933+REGN10987 and Moderna mRNA-1273 vaccine when administered in close succession * To assess the concentrations of REGN10933 and REGN10987 in serum over time in participants who receive REGN10933+REGN10987 and Moderna mRNA-1273 vaccine * To evaluate the immunogenicity of REGN10933 and REGN10987 over time

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Key information

Conditions

Healthy Chronic Stable Illness

Age range

18 year–90 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Regeneron Research Site, Little Rock, Arkansas, United States

Loading trial locations.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Key Inclusion Criteria:

  • Healthy or has chronic medical condition(s) that are stable and well-controlled in the opinion of the investigator and that are not likely to require significant medical intervention through the end of study
  • Willing and able to comply with study visits and study-related procedures, including compliance with site precautionary requirements related to SARS-CoV-2 infection and transmission

Key Exclusion Criteria:

  • Positive RT-PCR test result for SARS-CoV-2 infection at screening or baseline
  • Positive serology test result for anti-SARS-CoV-2 antibodies at screening or baseline
  • COVID-19 diagnosis, positive SARS-CoV-2 infection, or positive SARS-CoV-2 serology at any time prior to screening
  • Previously received an investigational, authorized, or approved coronavirus vaccine (eg, SARS-CoV-2 vaccine, MERS-CoV vaccine)
  • Currently enrolled in, or has plans to enroll in, any interventional study to prevent or treat COVID-19
  • Received investigational or approved passive antibodies for SARS-CoV-2 infection prophylaxis ad defined in the protocol
  • Received intravenous immunoglobulin (IVIG) or blood products in the last 3 months
  • Any physical examination findings and/or history of any illness that, in the opinion of the study investigator, might confound the results of the study or pose an additional risk to the subject by study participation
  • History of clinically significant cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, psychiatric or neurological disease, as assessed by the investigator, that may confound the results of the study or pose an additional risk to the subject by study participation
  • Medically attended acute illness or hospitalization (ie, >24 hours) for any reason within 30 days prior to screening
  • Clinical history of myocarditis and/or pericarditis

Note: Other protocol-defined Inclusion/ Exclusion Criteria apply

Treatment and study plan

casirivimab+imdevimab

Drug

Wave 1 Intravenous (IV) administration Wave 2 Subcutaneous administration

Other names: REGN10933, REGN10987, REGN-COV2, REGEN-COV™, Ronapreve™

Moderna mRNA-1273 vaccine

Biological

Single intramuscular (IM) injection

Primary outcomes

  1. 50% Inhibitory Dilution (ID50) Titers of Vaccine-induced Neutralizing Antibodies to the SARS-CoV-2 S Protein in Individuals Who Received High Dose REGN10933+REGN10987 (1200 mg)

    Time frame: 56 days after first dose of vaccine

    High dose - (1200 mg arms)

  2. 50% Inhibitory Dilution (ID50) Titers of Vaccine-induced Neutralizing Antibodies to the SARS-CoV-2 S Protein in Individual Who Received Submaximal Dose Levels of REGN10933+REGN10987 (Less Than 1200 mg)

    Time frame: 56 days after first dose of vaccine

    Submaximal dose - (150 mg, 300 mg, 600 mg, 48 mg, and 12 mg)

Secondary outcomes

  1. Absolute Values in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgA)

    Time frame: Up to 365 Days from 1st dose of Vaccination

    Anti-S1-RBD protein

  2. Median Fold Change of Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgA)

    Time frame: Up to 365 Days from 1st dose of Vaccination

    Anti-S1-RBD protein. Fold Change based on medians = (median value in vaccine only arm / median value in the active arm)

  3. Relative Difference Expressed as a Percent in Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgA)

    Time frame: Up to 365 Days from 1st dose of Vaccination

    Anti-S1-RBD protein. Relative difference is calculated as: [(LS Geometric Mean Active Arm - LS Geometric Mean Vaccine Alone Arm) / LS Geometric Mean Vaccine Alone Arm] x 100%

  4. Absolute Values in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgA)

    Time frame: Up to 365 Days from 1st dose of Vaccination

    • Anti-S protein (Spike protein)

  5. Fold Change of Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgA)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein Fold Change based on medians = (median value in vaccine only arm / median value in the active arm)

  6. Relative Difference Expressed as a Percent in Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgA)

    Time frame: Up to 365 Days from 1st dose of Vaccination

    Anti-S protein Relative difference is calculated as: [(LS Geometric Mean Active Arm - LS Geometric Mean Vaccine Alone Arm) / LS Geometric Mean Vaccine Alone Arm] x 100%

  7. Absolute Values in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgG)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein

  8. Fold Change of Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgG)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein Fold Change based on medians = (median value in vaccine only arm / median value in the active arm)

  9. Relative Difference Expressed as a Percent in Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgG)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein (Spike) Relative difference is calculated as: [(LS Geometric Mean Active Arm - LS Geometric Mean Vaccine Alone Arm) / LS Geometric Mean Vaccine Alone Arm] x 100%

  10. Absolute Values in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgG)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S1-RBD

  11. Fold Change of Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgG)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S1-RBD protein Fold Change based on medians = (median value in vaccine only arm / median value in the active arm)

  12. Relative Difference Expressed as a Percent in Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgG)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S1-RBD protein Relative difference is calculated as: [(LS Geometric Mean Active Arm - LS Geometric Mean Vaccine Alone Arm) / LS Geometric Mean Vaccine Alone Arm] x 100%

  13. Absolute Values in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgM)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S1-RBD

  14. Relative Difference Expressed as a Percent in Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgM)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S1-RBD protein Relative difference is calculated as: [(LS Geometric Mean Active Arm - LS Geometric Mean Vaccine Alone Arm) / LS Geometric Mean Vaccine Alone Arm] x 100%

  15. Fold Change of Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S1-RBD IgM)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S1-RBD protein Fold Change based on medians = (median value in vaccine only arm / median value in the active arm)

  16. Absolute Values in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgM)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein (Spike protein)

  17. Relative Difference Expressed as a Percent in Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgM)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein (Spike protein) Relative difference is calculated as: [(LS Geometric Mean Active Arm - LS Geometric Mean Vaccine Alone Arm) / LS Geometric Mean Vaccine Alone Arm] x 100%

  18. Fold Change of Concentrations of Vaccine-induced Antibodies to SARS-CoV-2 Antigens Over Time (S-IgM)

    Time frame: Up to 365 Days from 1st dose of vaccination

    Anti-S protein (Spike protein) Fold Change based on medians = (median value in vaccine only arm / median value in the active arm)

  19. 50% Inhibitory Dilution (ID50) Titers of Vaccine-induced Neutralizing Antibodies to SARS-CoV-2 S Protein Assessed Over Time After the First Dose of Moderna mRNA-1273 Vaccine

    Time frame: Up to 365 Days from 1st dose of vaccination

  20. Number of Participants With Treatment-emergent Adverse Events (TEAEs) Throughout the Study

    Time frame: Up to 401 Days

  21. Number of Participants With Treatment-emergent Serious Adverse Events (SAEs) Throughout the Study

    Time frame: Up to 401 Days

  22. Number of Participants With Infusion-related Reactions (Grade ≥2) to REGN10933+REGN10987

    Time frame: Through Day 4 post-infusion

  23. Number of Participants With Injection Site Reactions (Grade ≥3) to REGN10933+REGN10987

    Time frame: Through Day 4 post-infusion

  24. Number of Participants With Injection Site Reactions (Grade ≥3) to Moderna mRNA-1273 Vaccine

    Time frame: Through Day 4 post-infusion

  25. Number of Participants With Hypersensitivity Reactions (Grade ≥2) to REGN10933+REGN10987 or Each Dose of Moderna mRNA-1273 Vaccine

    Time frame: Through Day 29 post-infusion or post-injection

    Grade 2 - characterized by an adverse local or general response from exposure and oral intervention indicated Grade 3 - hospitalization indicated and intravenous response required Grade 4 - Life Threatening consequence and urgent intervention indicated Grade 5 - Death

  26. Concentrations of REGN10933 in Serum Over Time

    Time frame: Up to 182 Days

  27. Concentrations of REGN10987 in Serum Over Time

    Time frame: Up to 182 Days

  28. Immunogenicity, as Measured by Anti-drug Antibodies (ADA) to REGN10987

    Time frame: Up to Day 183

  29. Immunogenicity, as Measured by Anti-drug Antibodies (ADA) to REGN10933

    Time frame: Up to Day 183

  30. Immunogenicity, as Measured by Neutralizing Antibodies (NAb) to REGN10987

    Time frame: Up to Day 183

  31. Immunogenicity, as Measured by Neutralizing Antibodies (NAb) to REGN10933

    Time frame: Up to Day 183

Sponsors and collaborators

Lead sponsor

Regeneron Pharmaceuticals

Industry

Registry information

Official study title

A Phase 2 Randomized, Open-Label, Parallel Group Study to Assess the Immunogenicity, Safety, and Tolerability of Moderna mRNA-1273 Vaccine Administered With Casirivimab+Imdevimab in Healthy Adult Volunteers

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Apr 21, 2021
Registry last updated
Oct 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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