NCT07626411 · Regeneron Pharmaceuticals
Stroke and Systemic Embolism Prevention in Adult Participants With Atrial Fibrillation
(ROXI-EVEREST)
What this study is about
This study is researching an experimental drug called REGN7508 (called "study drug") and how it compares against another treatment called apixaban. The study is focused on people who have atrial fibrillation, which means that the heart beats too fast and unevenly.
View original scientific description
This study is researching an experimental drug called REGN7508 (called "study drug") and how it compares against another treatment called apixaban. The study is focused on people who have atrial fibrillation, which means that the heart beats too fast and unevenly. The aim of the study is to see how safe and effective REGN7508 is in preventing stroke and/or systemic embolism in participants with atrial fibrillation and how it compares against participants that will receive apixaban in this study.
Interventions
DRUG
REGN7508
Administered per the protocol
DRUG
Apixaban
Administered per the protocol
DRUG
Placebo
Administered per the protocol
Primary outcome measures
Time to first occurrence of stroke (ischemic, hemorrhagic, or of unspecified type) or systemic embolism
Time frame: Approximately 36 months
Time to first occurrence of International Society on Thrombosis and Haemostasis (ISTH) major bleeding or ISTH Clinically Relevant Non-Major (CRNM) bleeding
Time frame: Approximately 36 months
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Has AF or flutter (paroxysmal or persistent), not considered to be secondary to a reversible cause, and an indication for indefinite anticoagulation treatment as described in the protocol
- Meets one of the following:
- 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 ≥2 and Oral Anticoagulant (OAC) naïve OR
- CHA2DS2-VA score ≥3 OR
- CHA2DS2-VA score of 2 AND at least 1 enrichment criteria as described in the protocol
- Must have an International Normalized Ratio (INR) \<2.5 at the time of randomization if taking warfarin or another Vitamin K Antagonist (VKA) Key
Exclusion criteria
- Has a mechanical heart valve prosthesis (Note: transcatheter aortic valve replacement is not an exclusion)
- Has known moderate-to-severe mitral stenosis
- Has had a successful ablation therapy without documented recurrent AF or a participant after Left Atrial Appendage (LAA) occlusion/exclusion or plan for ablation or LAA occlusion/exclusion within the next 6 months starting from randomization
- Had an ischemic stroke within 2 days prior to randomization
- Has persistent, uncontrolled hypertension (per investigator's discretion)
- Has estimated Glomerular Filtration Rate (eGFR) \<15 mL/min/1.73m2 within 30 days prior to randomization or is on dialysis or expected to be started on dialysis within the next 6 months starting from randomization Note: Other protocol-defined Inclusion/ Exclusion criteria apply
Where
- Dothan, Alabama
- Newport Beach, California
- Pasadena, California
- Pensacola, Florida
- West Monroe, Louisiana
- Amarillo, Texas
- Houston, Texas
- Odessa, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 25, 2026 · Source of record for eligibility and locations