REGN7508 and REGN9933 for stroke prevention in atrial fibrillation when blood thinners are unsuitable
Tests REGN7508 and REGN9933 against placebo 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 for Whom Oral Anticoagulation is Unsuitable
Key facts
- Where
- Bucharest, Craiova, Dobrosloveni, Jud. Maramures, Mures County, Pitesti, Rosu, and Târgu Mureş, RomaniaSee the 8 sites
- Phase
- Phase 3
Where in Romania
- Spitalul Universitar de Urgență BucureștiBucharest, RomaniaNot yet recruiting
- Spitalul Clinic Județean de Urgență CraiovaCraiova, RomaniaNot yet recruiting
- Clintrial Medical Center S.R.L.Dobrosloveni, RomaniaNot yet recruiting
- Cabinet de Cardiologie CMI Dr. Calin PopJud. Maramures, RomaniaNot yet recruiting
- Cabinet de Cardiologie CMI Dr. Cristian PodoleanuMures County, RomaniaNot yet recruiting
- Sal Med S.R.L.Pitesti, RomaniaNot yet recruiting
- Vivamed Clinic S.R.L.Rosu, RomaniaNot yet recruiting
- Spitalul Clinic Judetean de Urgenta Targu MuresTârgu Mureş, RomaniaNot 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
- NCT07430956EU 2025-521618-25-00
- Record updated
- 10 November 2026
- Original description
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.Read full original descriptionShow less
A Master Protocol for a Phase 3, Randomized, Multicenter, Double-blind Study to Assess Stroke and Systemic Embolism Prevention With REGN7508 and REGN9933, Monoclonal Antibodies Against Factor XI, Versus Placebo in Participants With Atrial Fibrillation for Whom Oral Anticoagulation is Unsuitable (ROXI-INCLINE)
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)
Inclusion: Has AF or flutter (paroxysmal or persistent), not considered to be secondary to a reversible cause; At moderate to high risk for stroke defined as:; 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; CHA2DS2-VA score of 3 AND at least 1 enrichment criteria as described in the protocol; 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: Had an ischemic stroke within 2 days prior to randomization; Has a history of Central Nervous System (CNS) bleeding within 30 days prior to randomization; Has participated in a prior Factor XI (FXI) inhibitor study; Note: Other protocol-defined Inclusion/ Exclusion criteria apply; Has a mechanical heart valve prosthesis (Note: transcatheter aortic valve replacement is not an exclusion); Has persistent, uncontrolled hypertension (per investigator's discretion); Has a life expectancy less than 12 months.