Purpose

This study is researching 2 different experimental drugs called REGN7508 and REGN9933 (called "study drugs"). The study is focused on people who have atrial fibrillation, which means that the heart beats too fast and unevenly. When this happens, blood cannot move smoothly through the heart; it can slow down or pool in one spot, which can lead to the formation of blood clots. 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 effective and safe REGN7508 and REGN9933, individually, are in preventing ischemic stroke or systemic embolism in people with atrial fibrillation who cannot or may choose to not take blood thinners. The study is looking at several other research questions, including: - What side effects may happen from taking REGN7508 or REGN9933 - How well does REGN7508 or REGN9933 lower the risk of having an ischemic stroke and/or systemic embolism compared to the placebo - How well does REGN7508 or REGN9933 lower the risk of having a major health problem affecting heart and blood circulation compared to placebo - How well does REGN7508 or REGN9933 lower the risk of death compared to placebo - How much REGN7508 or REGN9933 is in the blood at different times - Whether the body makes antibodies against REGN7508 or REGN9933 (which could make the study drugs less effective or could lead to side effects)

Condition

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  1. Has AF or flutter (paroxysmal or persistent), not considered to be secondary to a reversible cause 2. At moderate to high risk for stroke defined as: 1. CHA2DS2-VA [C: Congestive heart failure; H: Hypertension; A2: Age ≥75 years (double points); D: Diabetes mellitus; S2: Stroke or TIA or Systemic embolism (double points); V: Vascular disease; A: Age 65-74 years] score ≥4 OR 2. CHA2DS2-VA score of 3 AND at least 1 enrichment criteria as described in the protocol 3. Shared decision making between the participant and provider determining that the bleeding risk of Oral Anticoagulant (OAC) therapy outweighs the benefits, making the participant unsuitable for OAC therapy as described in the protocol

Exclusion Criteria

  1. Has a mechanical heart valve prosthesis (Note: transcatheter aortic valve replacement is not an exclusion) 2. Had an ischemic stroke within 2 days prior to randomization 3. Has persistent, uncontrolled hypertension (per investigator's discretion) 4. Has a history of Central Nervous System (CNS) bleeding within 30 days prior to randomization 5. Has a life expectancy less than 12 months 6. Has participated in a prior Factor XI (FXI) inhibitor study Note: Other protocol-defined Inclusion/ Exclusion criteria apply

Study Design

Phase
Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Prevention
Masking
Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
REGN7508
  • Drug: REGN7508
    Administered per the protocol
    Other names:
    • cenvacibart
Experimental
REGN9933
  • Drug: REGN9933
    Administered per the protocol
    Other names:
    • amrecibart
Placebo Comparator
Placebo
  • Drug: Placebo
    Administered per the protocol

Recruiting Locations

SEC Clinical Research
Dothan, Alabama 36305

Mission Cardiovascular Research Institute
Fremont, California 94538

National Institute of California Heart and Vein Specialists
Huntington Beach, California 92648

Profound Research LLC at Southern California Heart Specialists
Pasadena, California 91105

Cardiology Associates Medical Group
Ventura, California 93003

Interventional Cardiology Medical Group
West Hills, California 91307

South Florida Research Organization LLC
Medley, Florida 33166

Clinical Site Partners, LLC DBA Flourish Research
Winter Park, Florida 32789

NSC Research, Inc
Johns Creek, Georgia 30024

Monroe Research, LLC
West Monroe, Louisiana 71291

AA Medical Research Center (MRC)
Flint, Michigan 48504

K&R Research LLC
Marion, Ohio 43302

PharmaTex Research
Amarillo, Texas 79106

More Details

Status
Recruiting
Sponsor
Regeneron Pharmaceuticals

Study Contact

Clinical Trials Administrator
844-734-6643
clinicaltrials@regeneron.com

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.