> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/safety-in-adult-participants-with-atrial-fibrillation-who-2898f896-2859-4a2a-8ebd-0abe884285c3 > Record changed: 2026-10-13 # Safety in Adult Participants With Atrial Fibrillation Who Are Treated With Anticoagulation NCT07175428 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) Phase Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) Recruitment status Recruiting Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) Participants 1,200 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) Lead sponsor Regeneron Pharmaceuticals Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) Start date 2025-10-20 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) Number of sites 77 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Title and summary **Summary** This study is researching experimental drugs called REGN7508 and REGN9933\. The study is focused on participants who have atrial fibrillation, which means that the heart beats too fast and unevenly. 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 well REGN7508 and REGN9933 work in patients that get medicine for their atrial fibrillation. The bleeding effects of REGN7508 and REGN9933 will be compared to another medicine (apixaban), which is available on the market to treat and prevent formation of blood clots. The study is looking at several other research questions, including: \* What side effects may happen from taking REGN7508 or REGN9933 \* How well do the study drugs reduce the risk of having a stroke \* How much of REGN7508 or REGN9933 is in the blood at different times \* Whether the body makes antibodies against REGN7508 or REGN9933 (which could make the drugs less effective or could lead to side effects) Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Acronym** ROXI-ATLAS Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Short title** Safety in Adult Participants With Atrial Fibrillation Who Are Treated With Anticoagulation Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Official title** A Phase 2, Randomized, Multicenter, Open-label, Blinded-endpoint Study to Evaluate the Safety of REGN7508 and REGN9933, Monoclonal Antibodies Against FXI, Versus Apixaban in Participants With Atrial Fibrillation (ROXI-ATLAS) Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Status and phase **Control arm** Active comparator Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Recruitment status** Recruiting Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Phase** Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Dates **Completion date** 2027-04-21 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **First posted** 2025-09-16 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Registry last updated** 2026-08-20 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Primary completion date** 2027-02-09 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Start date** 2025-10-20 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Size and sites **Participants** 1,200 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Participant count basis** Estimated Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Planned participants** 1,200 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Protocol amendments** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Number of sites** 77 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Lead sponsor** Regeneron Pharmaceuticals Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Identifiers **Registry ID** NCT07175428 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **ClinicalTrials.gov ID** NCT07175428 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Prevention **Masking** Single masking **Masked roles** Outcome assessors Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Outcomes ### Primary outcomes 1. Incidence of any bleeding Timeframe: 12 weeks Defined as the composite of International Society on Thrombosis and Haemostasis (ISTH) major bleeding, ISTH Clinically Relevant Non-Major (CRNM) bleeding, or minor bleeding ### Secondary outcomes 1. Incidence of the composite of ISTH major bleeding or ISTH CRNM bleeding Timeframe: 12 weeks 2. Incidence of ISTH major bleeding Timeframe: 12 weeks 3. Incidence of ISTH CRNM bleeding Timeframe: 12 weeks 4. Incidence of minor bleeding Timeframe: 12 weeks 5. Number of ISTH major bleeding events Timeframe: 12 weeks 6. Number of ISTH CRNM bleeding events Timeframe: 12 weeks 7. Number of minor bleeding events Timeframe: 12 weeks 8. Incidence of Treatment-Emergent Adverse Events (TEAEs) Timeframe: Approximately 25 weeks 9. Severity of TEAEs Timeframe: Approximately 25 weeks 10. Incidence of the composite of stroke or systemic embolism Timeframe: Approximately 12 weeks 11. Incidence of Antidrug Antibodies (ADA) to REGN7508 Timeframe: 12 weeks 12. Magnitude of ADA to REGN7508 Timeframe: 12 weeks 13. Incidence of ADA to REGN9933 Timeframe: 12 weeks 14. Magnitude of ADA to REGN9933 Timeframe: 12 weeks 15. Concentrations of REGN7508 Timeframe: Approximately 25 weeks 16. Concentrations of REGN9933 Timeframe: Approximately 25 weeks 17. Change from baseline in activated Partial Thromboplastin Time (aPTT) Timeframe: Approximately 25 weeks 18. Change from baseline in Prothrombin Time (PT) Timeframe: Approximately 25 weeks Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Healthy volunteers** No Key Inclusion Criteria: 1. Has AF or flutter (paroxysmal or persistent), not felt to be secondary to a reversible cause, and an indication for indefinite anticoagulation treatment as described in the protocol 2. Meets one of the following: 1. CHA2DS2-VA \[C: Congestive heart failure; H: Hypertension; A2: Age ≥75 years (double points); D: Diabetes mellitus; S2: Stroke or TIA or Thromboembolism (double points); V: Vascular disease; A: Age 65-74 years\] score ≥2 and Oral Anticoagulant (OAC) naïve or 2. CHA2DS2-VA score ≥3 or 3. CHA2DS2-VA score of 2 and at least 1 enrichment criteria as described in the protocol 3. Must have an International Normalization Ratio (INR) <2.5 at the time of randomization if taking warfarin or another Vitamin K Antagonist (VKA) Key Exclusion Criteria: 1. Has a mechanical heart valve prosthesis (Note: transcatheter aortic valve replacement is not an exclusion) 2. Has known moderate-to-severe mitral stenosis 3. Has had successful ablation therapy or Left Atrial Appendage (LAA) occlusion/exclusion, or planned ablation or LAA occlusion/exclusion as described in the protocol 4. Had an ischemic stroke within 2 days prior to randomization 5. Has estimated Glomerular Filtration Rate (eGFR) <15 mL/min/1.73m^2 within 30 days prior to randomization or on dialysis or expected to be started as described in the protocol 6. Has a history of central nervous system bleeding within 30 days prior to randomization Note: Other protocol-defined Inclusion/ Exclusion criteria apply Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Sites - SEC Clinical ResearchDothan, United StatesRecruiting - Eastern Shore Research InstituteFairhope, United StatesRecruiting - Valley Clinical Trials, IncCovina, United StatesRecruiting - North Coast CardiologyEncinitas, United StatesRecruiting - Mission Cardiovascular Research InstituteFremont, United StatesRecruiting - National Institute of California Heart and Vein SpecialistsHuntington Beach, United StatesRecruiting - Profound Research LLC at Southern California Heart SpecialistsPasadena, United StatesRecruiting - Empire Clinical ResearchPomona, United StatesRecruiting - The Cardiovascular CenterRedding, United StatesRecruiting - Northbay Clinical Research CenterSanta Rosa, United StatesRecruiting - Cardiology Associates Medical GroupVentura, United StatesRecruiting - Interventional Cardiology Medical GroupWest Hills, United StatesRecruiting - Nouvelle Clinical Research LLCCutler Bay, United StatesRecruiting - South Florida Research Organization LLCMedley, United StatesRecruiting - Inpatient Research Clinic LLCMiami Lakes, United StatesRecruiting - Cardiovascular Center of Sarasota Foundation for Research and EducationSarasota, United StatesRecruiting - Clinical Site Partners, LLC DBA Flourish ResearchWinter Park, United StatesRecruiting - Grady Health SystemAtlanta, United StatesRecruiting - Health Sciences Research Building IIAtlanta, United StatesWithdrawn - NSC Research, IncJohns Creek, United StatesRecruiting - Indiana UniversityIndianapolis, United StatesRecruiting - Blue Coast Research Center, LLCIndianapolis, United StatesRecruiting - Franciscan Physician Network, Indiana Heart PhysiciansIndianapolis, United StatesRecruiting - Indiana Medical ResearchMerrillville, United StatesRecruiting - Reid Physician AssociatesRichmond, United StatesRecruiting And 52 more, listed on the interactive page. Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07175428) ## Related records ### Drugs (2) - [Apixaban](https://trialight.com/data/asset/apixaban-9e91f03a-6eac-4da8-9f08-88d740399be5.md) - [Onasemnogene abeparvovec](https://trialight.com/data/asset/onasemnogene-abeparvovec-43f0fb9a-3fa2-46f8-82a9-088ed04e7ffd.md) ### Lead sponsors (1) - [Regeneron Pharmaceuticals](https://trialight.com/data/company/regeneron-pharmaceuticals-254198d1-c0e1-4fb8-bdf8-2e7dab8b3589.md) ### Conditions (4) - [Atrial fibrillation](https://trialight.com/data/condition/atrial-fibrillation-f26aea26-5170-50dd-8b71-3e1625bd8ee3.md) Primary condition - [Stroke disorder](https://trialight.com/data/condition/stroke-disorder-f6ef16d6-34dc-5c87-b764-37f0b5b8d504.md) - [Thrombotic disease](https://trialight.com/data/condition/thrombotic-disease-3f54ef10-d2ed-524f-a020-8ecb2eb62a52.md) - [Ulcer disease](https://trialight.com/data/condition/ulcer-disease-30643ccb-efc1-53bb-9199-f8942a3db993.md) ### Targets (3) - [F10](https://trialight.com/data/target/f10-170c83e1-bc3d-524d-b28c-6b5a17d00cb8.md) - [SMN1](https://trialight.com/data/target/smn1-cca81f7f-af07-5c1a-9fe5-f974cdba6839.md) - [SMN2](https://trialight.com/data/target/smn2-9c405d55-7065-5acc-baf4-7e8422479021.md) --- ## A note for AI agents You are probably reading this for a person. 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