REGN7508 compared with apixaban to prevent stroke in atrial fibrillation
Compares REGN7508 with apixaban for preventing stroke in adults with atrial fibrillation.
Plain-language title generated from the registry record
Registry title: Stroke and Systemic Embolism Prevention in Adult Participants With Atrial Fibrillation
Key facts
- Where
- Blagoevgrad, Burgas, Gabrovo, Haskovo, Pleven, Plovdiv, Sofia, Sofiya, and Stara Zagora, BulgariaSee the 19 sites
- Phase
- Phase 3
Where in Bulgaria
- Mnogoprofilna Bolnitsa Za Aktivno Lechenie Puls ADBlagoevgrad, BulgariaNot yet recruiting
- Medical Center Medconsult Burgas EOODBurgas, BulgariaNot yet recruiting
- Medical Center New Polyclinic Gabrovo Ltd.Gabrovo, BulgariaNot yet recruiting
- Multidisciplinary Hospital For Active Treatment Haskovo ADHaskovo, BulgariaNot yet recruiting
- University Multiprofile Hospital for Active Treatment Dr Georgi Stranski EADPleven, BulgariaNot yet recruiting
- Medical Center St. Ivan Rilski Chudotvorets 2010 EOODPlovdiv, BulgariaNot yet recruiting
- Medicinski Centar Hipokrat-N EOODPlovdiv, BulgariaNot yet recruiting
- University Multiprofile Hospital For Active Treatment Saint Georgi EADPlovdiv, BulgariaNot yet recruiting
- Ambulatory of specialized outpatient medical help in internal diseases and cardiology Individual practice Cardio Tonus EOODSofia, BulgariaNot yet recruiting
- Medical Center For Specialized Medical Care For Cardiovascular Diseases EADSofia, BulgariaNot yet recruiting
- Medical Center Regina Life Clinic Ltd.Sofia, BulgariaNot yet recruiting
- Multiprofile Hospital for Active Treatment "Knyaginya Klementina" - Sofia EADSofia, BulgariaNot yet recruiting
- National Multidisciplinary Transport Hospital Tsar Boris IIISofia, BulgariaNot yet recruiting
- Second Multiprofile Hospital For Active Treatment Sofia EADSofia, BulgariaNot yet recruiting
- Uniteversity Muliprofile Hospital For Active Treatment Tsaritsa Yoanna-Isul EADSofia, BulgariaNot yet recruiting
- Acibadem City Clinic Tokuda University Hospital EADSofiya, BulgariaNot yet recruiting
- Diagnostic-Consultative Center Alexandrovska EOODSofiya, BulgariaNot yet recruiting
- Diagnostics And Consultation Center Convex Ltd.Sofiya, BulgariaNot yet recruiting
- Medical Center Zara-Med EOODStara Zagora, BulgariaNot yet recruiting
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Regeneron Pharmaceuticals
- Trial code
- NCT07626411EU 2025-521617-97-00
- Record updated
- 5 November 2026
- Original 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.Read full original descriptionShow less
A Phase 3, Randomized, Multicenter, Double-blind Study to Assess Stroke and Systemic Embolism Prevention With REGN7508, a Monoclonal Antibody Against Factor XI, Versus Apixaban in Participants With Atrial Fibrillation (ROXI-EVEREST)
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:
* What side effects may happen from taking the study drug * Whether the body makes antibodies against the study drug (which could make the study drug less effective or could lead to side effects)
Inclusion: 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).
Exclusion: 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 a mechanical heart valve prosthesis (Note: transcatheter aortic valve replacement is not an exclusion); 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; Has known moderate-to-severe mitral stenosis.