A Study to Evaluate Efficacy and Safety of Casirivimab+Imdevimab (Monoclonal Antibodies) for Prevention of COVID-19 in Immunocompromised Adolescents and Adults

NCT05074433 | Terminated Phase 3 Results DMC FDA Drug

• 2 other identifiers: R10933-10987-COV-21762021-005222-14
• Study Type: interventional
• Target: 66
• Locations: 2 countries
• Sites: 67

Brief Summary

The primary objective of the study is to evaluate the effect of casirivimab+imdevimab, compared with placebo, in preventing symptomatic SARS-CoV-2 infection in immunocompromised participants. The secondary objectives of the study are:

• To evaluate the safety and tolerability of repeated SC injections of casirivimab+imdevimab in the study population
• To characterize concentrations of casirivimab and imdevimab in serum over time
• To assess the immunogenicity of casirivimab and imdevimab

Conditions

Immunocompromised

Keywords

Non-response to COVID-19 vaccination; COVID-19; Immunocompromised, weakened immune system

Outcome Measures

Primary Outcomes (1)

• Cumulative Incidence of Symptomatic (Broad Term), RT-PCR-confirmed SARS-CoV-2 Infection Cases During the EAP

  Cumulative incidence of symptomatic (broad term), RT-PCR-confirmed SARS-CoV-2 infection cases during the Efficacy Assessment Period (EAP)

  The EAP was defined as the day from first dose of study drug to day 169 +/- 7 days

Secondary Outcomes (11)

• Number of Participants With Grade ≥3 Treatment-emergent Adverse Events (TEAEs) During the EAP

  The EAP was defined as the day from first dose of study drug to day 169 +/- 7 days

• Number of Participants With Grade ≥3 Treatment-emergent Adverse Events (TEAEs) During the Follow-Up Period

  End of EAP to the end of the Follow-Up Period (Day 169 to 205, approximately ~1 months)

• Number of Participants With TEAEs Leading to Study Drug Discontinuation During the EAP

  The EAP was defined as the day from first dose of study drug to day 169 +/- 7 days

• Number of Participants With TEAEs Leading to Study Drug Discontinuation During the Follow-Up Period

  End of EAP to the end of the Follow-Up Period (Day 169 to 205, approximately ~1 months)

• Number of Participants With Treatment-emergent Serious Adverse Events (SAEs) During the EAP

  The EAP was defined as the day from first dose of study drug to day 169 +/- 7 days

Study Arms (4)

casirivimab+imdevimab Initial + Q4W

EXPERIMENTAL

Initial subcutaneous (SC) dose, then SC dose every 4 weeks (Q4W)

Drug: casirivimab+imdevimab

casirivimab+imdevimab Q4W

EXPERIMENTAL

SC dose Q4W

Drug: casirivimab+imdevimab

casirivimab+imdevimab Q12W

EXPERIMENTAL

SC dose every 12 weeks (Q12W)

Drug: casirivimab+imdevimab

Placebo

PLACEBO COMPARATOR

SC dose Q4W

Drug: Placebo

Interventions

casirivimab+imdevimab DRUG

Co-administered sequentially subcutaneous (SC)

Also known as: REGN-COV2, REGN10933, REGN10987, REGEN-COV™, Ronapreve™

casirivimab+imdevimab Initial + Q4W; casirivimab+imdevimab Q12W; casirivimab+imdevimab Q4W

Placebo DRUG

Administered SC

Placebo

Eligibility Criteria

• Age: 12 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Meets ≥1 of the following criteria:
• Is immunocompromised, including people with transplant, who have cancer, primary immunodeficiencies, HIV, rheumatological disease, autoimmune disease, multiple sclerosis OR
• Currently taking immunosuppressant drugs
• Have been fully vaccinated against COVID-19 or deemed medically ineligible to receive full course of vaccine
• Has documented negative serology/antibody response in an anti-SARS-CoV-2 spike protein IgG clinical test or ≤50 U/mL on the Elecsys® SARS-CoV-2 S Total Ig test
• Tested negative for the COVID-19 virus within 72 hours prior to randomization

You may not qualify if:

• Weighs \<40 kg (only applies to participants ≥12 to \<18 years of age)
• Has any signs or symptoms consistent with COVID-19
• Past COVID-19 infection within 90 days prior to randomization
• Planned use of any investigational, authorized, or approved vaccine for COVID-19 within 90 days of the last dose of study drug
• Prior, current, or planned use of any of COVID-19 convalescent plasma, other monoclonal antibodies against SARS-CoV-2 or any COVID-19 treatment
• Is planned to begin immunoglobulin (IVIG) or immunoglobulin (SCIG) therapy, is planned to have a change to existing IVIG or SCIG, or has been on a chronic stable dose of their IVIG or SCIG regimen for less than 90 days prior to screening
• Has any known active acute respiratory infection
• Has persistent (refractory to treatment for ≥14 days) bacterial or fungal infection
• Has known allergy or hypersensitivity to components of the study drugs

Sponsors & Collaborators

• Regeneron Pharmaceuticals: lead

Study Sites (67)

Central Alabama Research

Birmingham, Alabama, 35205, United States

Location

Baptist Health Center for Clinical Research

Little Rock, Arkansas, 72205, United States

Location

Regeneron Study Site

Long Beach, California, 90806, United States

Location

Regeneron Study Site

Los Angeles, California, 90033, United States

Location

Cedars-Sinai Medical Center

Los Angeles, California, 90048, United States

Location

Stanford University

Palo Alto, California, 94304, United States

Location

University of California

Sacramento, California, 95817, United States

Location

Regeneron Study Site

Stanford, California, 94305, United States

Location

James R Berenson MD Inc.

West Hollywood, California, 90069, United States

Location

University Of Colorado

Aurora, Colorado, 80045, United States

Location

Regeneron Study Site

North Haven, Connecticut, 06473-2195, United States

Location

Georgetown University

Washington D.C., District of Columbia, 20007, United States

Location

Arthritis and Rheumatic Disease Specialties

Aventura, Florida, 33180, United States

Location

Innovative Research of West Florida, Inc.

Clearwater, Florida, 33756, United States

Location

Midway Immunology and Research Center

Ft. Pierce, Florida, 34982, United States

Location

Elixia COVID-19

Hollywood, Florida, 33024, United States

Location

AppleMed Research Group, LLC

Miami, Florida, 33126, United States

Location

De La Cruz Research Center, LLC

Miami, Florida, 33184, United States

Location

University of South Florida

Tampa, Florida, 33606, United States

Location

Florida Medical Clinic, LLC

Zephyrhills, Florida, 33542, United States

Location

Regeneron Study Site

Atlanta, Georgia, 30322, United States

Location

Regeneron Study Site

Marietta, Georgia, 30060, United States

Location

Great Lakes Clinical Trials - Ravenswood

Chicago, Illinois, 60625, United States

Location

University of Iowa

Iowa City, Iowa, 52242, United States

Location

Tulane University

New Orleans, Louisiana, 70112, United States

Location

Institute of Human Virology

Baltimore, Maryland, 21201, United States

Location

Johns Hopkins Hospital

Baltimore, Maryland, 21287, United States

Location

Laboratory of Clinical Immunology and Microbiology, NIAID

Bethesda, Maryland, 20892, United States

Location

Tufts Medical Center

Boston, Massachusetts, 02111, United States

Location

Regeneron Study Site

Boston, Massachusetts, 02115, United States

Location

Beth Israel Deaconess Medical Center

Boston, Massachusetts, 02215, United States

Location

University of Michigan

Ann Arbor, Michigan, 48109, United States

Location

Spectrum Health

Grand Rapids, Michigan, 49503, United States

Location

Mayo Clinic

Rochester, Minnesota, 55905, United States

Location

University of Nebraska Medical Center

Omaha, Nebraska, 68198, United States

Location

Jersey Shore University Medical Center

Neptune City, New Jersey, 07753, United States

Location

Holy Name

Teaneck, New Jersey, 07666, United States

Location

Maimonides Cancer Center

Brooklyn, New York, 11220, United States

Location

Icahn School of Medicine at Mount Sinai

New York, New York, 10029, United States

Location

Regeneron Study Site

New York, New York, 10032-3729, United States

Location

Memorial Sloan Kettering Cancer Center

New York, New York, 10065, United States

Location

Regeneron Study Site 2

New York, New York, 10065, United States

Location

Regeneron Study Site

Rochester, New York, 14642, United States

Location

Regeneron Study Site

Syracuse, New York, 13210, United States

Location

SUNY Upstate Medical University

Syracuse, New York, 13215, United States

Location

Montefiore Medical Center

The Bronx, New York, 10467, United States

Location

Burke Primary Care

Morganton, North Carolina, 28655, United States

Location

Gabrail Cancer Center Research

Canton, Ohio, 44718, United States

Location

Regeneron Study Site

Cleveland, Ohio, 44195, United States

Location

Miami Valley Hospital

Dayton, Ohio, 45409, United States

Location

Altoona Center for Clinical Research

Duncansville, Pennsylvania, 16635, United States

Location

Penn Prevention Clinical Research Site

Philadelphia, Pennsylvania, 19104, United States

Location

Temple University

Philadelphia, Pennsylvania, 19140, United States

Location

Regeneron Study Site

Providence, Rhode Island, 02903, United States

Location

West Tennessee Research Institute

Jackson, Tennessee, 38305, United States

Location

PharmaTex Research, LLC

Amarillo, Texas, 79109, United States

Location

Central Texas Clinical Research

Austin, Texas, 78705, United States

Location

Therapeutic Concepts, PA

Houston, Texas, 77004, United States

Location

Houston Methodist Hospital

Houston, Texas, 77030, United States

Location

MD Anderson Cancer Center

Houston, Texas, 77030, United States

Location

Synergy Group Medical,LLC

Houston, Texas, 77087, United States

Location

Regeneron Study Site

Richmond, Virginia, 23219, United States

Location

Fred Hutchinson Cancer Research Center

Seattle, Washington, 98109, United States

Location

Regeneron Study Site

Seattle, Washington, 98109, United States

Location

Swedish Medical Center- First Hill

Seattle, Washington, 98122, United States

Location

University of Wisconsin - Madison

Madison, Wisconsin, 53792, United States

Location

Regeneron Study Site

Cuauhtémoc, Mexico City, 6700, Mexico

Location

MeSH Terms

Conditions

COVID-19

Interventions

casirivimab and imdevimab drug combination; casirivimab; imdevimab

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Results Point of Contact

• Title: Clinical Trials Administrator
• Organization: Regeneron Pharmaceuticals, Inc.

clinicaltrials@regeneron.com

8447346643

Study Officials

• Clinical Trial Management

  Regeneron Pharmaceuticals

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 8, 2021
• First Posted: October 12, 2021
• Study Start: October 25, 2021
• Primary Completion: May 18, 2022
• Study Completion: May 18, 2022
• Last Updated: October 20, 2025
• Results First Posted: July 24, 2023

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• 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.
• 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

Locations

ME (1); US (66)