Recruiting

Phase 2

REGN7508 & REGN9933Safety in Adult Participants With Atrial Fibrillation Who Are Treated With Anticoagulation

Sponsor:

Regeneron Pharmaceuticals

Code:

NCT07175428

Conditions

Atrial Fibrillation (AF)

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

REGN7508

REGN9933

Apixaban

Study Details

Brief summary:

This study is researching experimental drugs called REGN7508 and REGN9933. The study is focused on participants who have atrial fibrillation, which means that the heart beats too fast and unevenly. REGN7508 and REGN9933 are designed to help stop blood clots forming in patients with atrial fibrillation.

The aim of the study is to see how well REGN7508 and REGN9933 work in patients that get medicine for their atrial fibrillation. The bleeding effects of REGN7508 and REGN9933 will be compared to another medicine (apixaban), which is available on the market to treat and prevent formation of blood clots.

The study is looking at several other research questions, including:

What side effects may happen from taking REGN7508 or REGN9933
How well do the study drugs reduce the risk of having a stroke
How much of REGN7508 or REGN9933 is in the blood at different times
Whether the body makes antibodies against REGN7508 or REGN9933 (which could make the drugs less effective or could lead to side effects)

Conditions

Atrial Fibrillation (AF)

Study ID

NCT07175428

Start date

Oct 20, 2025

Status verified date

Aug, 2026

Completion date

Apr 21, 2027

Anticipated

Primary completion date

Feb 9, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

1. Has AF or flutter (paroxysmal or persistent), not felt to be secondary to a reversible cause, and an indication for indefinite anticoagulation treatment as described in the protocol
2. Meets one of the following:

1. CHA2DS2-VA \[C: Congestive heart failure; H: Hypertension; A2: Age ≥75 years (double points); D: Diabetes mellitus; S2: Stroke or TIA or Thromboembolism (double points); V: Vascular disease; A: Age 65-74 years\] score ≥2 and Oral Anticoagulant (OAC) naïve or
2. CHA2DS2-VA score ≥3 or
3. CHA2DS2-VA score of 2 and at least 1 enrichment criteria as described in the protocol
3. Must have an International Normalization Ratio (INR) <2.5 at the time of randomization if taking warfarin or another Vitamin K Antagonist (VKA)

Key Exclusion Criteria:

1. Has a mechanical heart valve prosthesis (Note: transcatheter aortic valve replacement is not an exclusion)
2. Has known moderate-to-severe mitral stenosis
3. Has had successful ablation therapy or Left Atrial Appendage (LAA) occlusion/exclusion, or planned ablation or LAA occlusion/exclusion as described in the protocol
4. Had an ischemic stroke within 2 days prior to randomization
5. Has estimated Glomerular Filtration Rate (eGFR) <15 mL/min/1.73m\^2 within 30 days prior to randomization or on dialysis or expected to be started as described in the protocol
6. Has a history of central nervous system bleeding within 30 days prior to randomization

Note: Other protocol-defined Inclusion/ Exclusion criteria apply

Study Design

Enrollment

1200 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: REGN7508

experimental: REGN9933

active comparator: Apixaban

Interventions

REGN7508

Administered per the protocol

REGN9933

Administered per the protocol

Apixaban

Administered per the protocol

Primary outcome measure

Incidence of any bleeding [ Time Frame: 12 weeks ]

Central Contacts and Locations

Central contacts

Clinical Trials Administrator

844-734-6643 clinicaltrials@regeneron.com

Locations

SEC Clinical Research

Recruiting

Dothan, Alabama, United States, 36305

Eastern Shore Research Institute

Recruiting

Fairhope, Alabama, United States, 36532

Valley Clinical Trials, Inc

Recruiting

Covina, California, United States, 91723

North Coast Cardiology

Recruiting

Encinitas, California, United States, 92024

Mission Cardiovascular Research Institute

Recruiting

Fremont, California, United States, 94538

National Institute of California Heart and Vein Specialists

Recruiting

Huntington Beach, California, United States, 92648

Profound Research LLC at Southern California Heart Specialists

Recruiting

Pasadena, California, United States, 91105

Empire Clinical Research

Recruiting

Pomona, California, United States, 91767

The Cardiovascular Center

Recruiting

Redding, California, United States, 96001

Northbay Clinical Research Center

Recruiting

Santa Rosa, California, United States, 95405

Cardiology Associates Medical Group

Recruiting

Ventura, California, United States, 93003

Interventional Cardiology Medical Group

Recruiting

West Hills, California, United States, 91307

Nouvelle Clinical Research LLC

Recruiting

Cutler Bay, Florida, United States, 33189

South Florida Research Organization LLC

Recruiting

Medley, Florida, United States, 33166

Inpatient Research Clinic LLC

Recruiting

Miami Lakes, Florida, United States, 33014

Cardiovascular Center of Sarasota Foundation for Research and Education

Recruiting

Sarasota, Florida, United States, 34239

Clinical Site Partners, LLC DBA Flourish Research

Recruiting

Winter Park, Florida, United States, 32789

Grady Health System

Recruiting

Atlanta, Georgia, United States, 30303

NSC Research, Inc

Recruiting

Johns Creek, Georgia, United States, 30024

Indiana University

Recruiting

Indianapolis, Indiana, United States, 46202

Blue Coast Research Center, LLC

Recruiting

Indianapolis, Indiana, United States, 46237

Franciscan Physician Network, Indiana Heart Physicians

Recruiting

Indianapolis, Indiana, United States, 46237

Indiana Medical Research

Recruiting

Merrillville, Indiana, United States, 46410

Reid Physician Associates

Recruiting

Richmond, Indiana, United States, 47374

Monroe Research, LLC

Recruiting

West Monroe, Louisiana, United States, 71291

Anderson Medical Research

Recruiting

Ft. Washington, Maryland, United States, 20744

Beth Israel Lahey Health, Beth Israel Deaconess Medical Center (BIDMC)

Recruiting

Boston, Massachusetts, United States, 02215

Profound Research, Millennium Cardiology

Recruiting

Farmington Hills, Michigan, United States, 48334

AA Medical Research Center (MRC)

Recruiting

Flint, Michigan, United States, 48504

Fairview Health Services

Recruiting

Maplewood, Minnesota, United States, 55109

Moses Cone Hospital Operating Corporation dba Cone Health, Lebauer-Brodie Center for Cardiovascular Research

Recruiting

Greensboro, North Carolina, United States, 27401

K&R Research LLC

Recruiting

Marion, Ohio, United States, 43302

Advanced Medical Research

Recruiting

Maumee, Ohio, United States, 43537

Monument Health Clinical Research

Recruiting

Rapid City, South Dakota, United States, 57701

East Coast Institute for Research, Jefferson City

Recruiting

Jefferson City, Tennessee, United States, 37760

PharmaTex Research

Recruiting

Amarillo, Texas, United States, 79106

Complete Heart Care P.A.

Recruiting

McKinney, Texas, United States, 75071

Texas Institute of Cardiology PA

Recruiting

McKinney, Texas, United States, 75071

Synergy Group Medical, LLC

Recruiting

Missouri City, Texas, United States, 77459

Permian Research Foundation

Recruiting

Odessa, Texas, United States, 79761

Tyler Cardiovascular Consultants

Recruiting

Tyler, Texas, United States, 75701

Alpine Research TC

Recruiting

Clinton, Utah, United States, 84015

University of Alberta Hospital - Cardiology

Recruiting

Edmonton, Alberta, Canada, T6G 2G3

Victoria Cardiac Arrhythmia Trials

Recruiting

Victoria, British Columbia, Canada, V8Z 0B9

GA Research Associates Ltd.

Recruiting

Moncton, New Brunswick, Canada, E1G-1A7

Health sciences North - Cardiology

Recruiting

Greater Sudbury, Ontario, Canada, P3E 5J1

Hamilton Health Sciences Corporation

Recruiting

Hamilton, Ontario, Canada, L8L 2X2

Hamilton Medical Research Group (HMRG)

Recruiting

Hamilton, Ontario, Canada, L8L 5G4

Dr James Cha

Recruiting

Oshawa, Ontario, Canada, L1J 2K1

Heart Health Institute Research Inc. - Cardiology

Recruiting

Scarborough Village, Ontario, Canada, M1B 4Z8

Viacar Recherches Cliniques Inc. - Cardiologie

Recruiting

Longueuil, Quebec, Canada, J4H 4B9

Centre Hospitalier Universitaire De Sherbrooke (CHUS) - Cardiologie

Recruiting

Sherbrooke, Quebec, Canada, J1H 5N4

Diex Recherche Inc.

Recruiting

Sherbrooke, Quebec, Canada, J1LOK3

Diex Recherche Trois-rivieres

Recruiting

Trois-Rivières, Quebec, Canada, G9A 4P3

CHU de Quebec-Universite Laval

Recruiting

Québec, Canada, G1R 2J6

More Information

Sponsor

Regeneron Pharmaceuticals

Last update posted

Aug 20, 2026

Last verified

Aug, 2026

Keywords

Bleeding
Stroke
Systemic embolism
Blood clots

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Regeneron Pharmaceuticals on 2026-08-20.