A Phase 3 interventional study of REGN7508 and Apixaban in Atrial Fibrillation (AF), sponsored by Regeneron Pharmaceuticals. Recruiting at 66 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Regeneron Pharmaceuticals · Phase 3, Interventional, and Prevention
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.
The study is looking at several other research questions, including:
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 15,364 is above the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Regeneron Pharmaceuticals is the lead sponsor of 411 studies on the registry; 90 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 79 (63%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Meets one of the following:
Key Exclusion Criteria:
Note: Other protocol-defined Inclusion/ Exclusion criteria apply
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: REGN7508 · Drug: Placebo
Drug: Apixaban · Drug: Placebo
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
Time to first occurrence of stroke (ischemic, hemorrhagic, or of unspecified type), systemic embolism, ISTH major bleeding, or ISTH CRNM bleeding
Time frame: Approximately 36 months
Time to first occurrence of stroke (ischemic, hemorrhagic, or of unspecified type), systemic embolism, or ISTH major bleeding
Time frame: Approximately 36 months
Time to first occurrence of stroke (ischemic, hemorrhagic, or of unspecified type), systemic embolism, ISTH major bleeding, or all-cause death
Time frame: Approximately 36 months
Time to first occurrence of ISTH major bleeding
Time frame: Approximately 36 months
Time to first occurrence of hemorrhagic stroke, intracerebral hemorrhage, or hemorrhagic transformation of an ischemic stroke
Time frame: Approximately 36 months
Time to occurrence of fatal bleeding
Time frame: Approximately 36 months
Number of ISTH major bleeding events
Time frame: Approximately 36 months
Number of ISTH CRNM bleeding events
Time frame: Approximately 36 months
Number of minor bleeding events
Time frame: Approximately 36 months
Time to all-cause death
Time frame: Approximately 36 months
Occurrence of Treatment-Emergent Adverse Events (TEAEs)
Time frame: Approximately 39 months
Severity of TEAEs
Time frame: Approximately 39 months
Occurrence of Anti-Drug Antibodies (ADA) to REGN7508
Time frame: Approximately 36 months
Magnitude of ADA to REGN7508
Time frame: Approximately 36 months
Plan to share: Yes — All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, 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 or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry) the legal authority to share the data, and 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
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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