REGN7508 Versus Apixaban and Enoxaparin for Thromboprophylaxis After Total Knee Arthroplasty in Adults
A Phase 3, Multicenter, Randomized, Open-Label, Study to Evaluate REGN7508, A Factor XI Monoclonal Antibody, Versus Apixaban and Enoxaparin for Prophylaxis of Venous Thromboembolism After Elective Total Knee Arthroplasty (ROXI-APEX)
- Venous Thromboembolism (VTE)
At a glance
- Phase
- Phase 3
- Study type
- Interventional
- Sponsor
- Regeneron Pharmaceuticals
- Enrolment target
- 2,000
- Started
- 25 June 2025
- Main results due
- 20 February 2027
- Study sites
- 47
- Registry updated
- 28 September 2026
Can you take part?
- Aged 18 years and over.
- Open to any sex.
- You need the condition being studied — healthy volunteers are not accepted.
These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.
Read the full eligibility criteria
Key Inclusion Criteria: 1. Is undergoing a primary elective unilateral TKA 2. Is in good health based on laboratory safety testing as described in the protocol 3. Body weight ≤130 kg at screening visit as described in the protocol Key Exclusion Criteria: 1. Any condition that, as assessed by the investigator, may confound the results of the study or pose an additional risk to the participant by study participation 2. History of bleeding in the 6 months prior to randomization requiring hospitalization or transfusion as described in the protocol 3. History of thromboembolic disease or thrombophilia 4. History of major surgery, including brain, spinal, or ocular, or major trauma within approximately the past 6 months prior to randomization 5. Has an estimated Glomerular Filtration Rate (GFR) of \<30 mL/min/1.73 m2 at the screening visit as described in the protocol Note: Other protocol-defined Inclusion/ Exclusion Criteria apply
What this study is about
In the sponsor’s own words, from the registry.
This study is researching an experimental drug called REGN7508 (called "study drug"). The study is focused on adults undergoing elective, unilateral (one side) total knee replacement surgery.
The aim of the study is to see how effective the study drug is at preventing Venous Thromboembolism (VTE) and other related diseases after total knee replacement surgery.
The study is looking at several other research questions, including:
* What side effects may happen from taking the study drug * How much study drug is in the blood at different times * Whether the body makes antibodies against the study drug (which could make the study drug less effective or could lead to side effects)
Study sites(47)
Shoals Medical Trials, Inc.
Sheffield, Alabama, United States
Recruiting
CARI Clinical Trials
Riverside, California, United States
Recruiting
Denver Metro Orthopedics, P.C. Englewood Location
Englewood, Colorado, United States
Recruiting
Delray Physician Care Center
Delray Beach, Florida, United States
Recruiting
Bioresearch Partner
Miami, Florida, United States
Recruiting
Sacred Heart Health System Inc
Pensacola, Florida, United States
Recruiting
Gulfcoast Research Institute
Sarasota, Florida, United States
Recruiting
Phoenix Clinical Research
Tamarac, Florida, United States
Recruiting
Sinai Hospital of Baltimore, Inc.
Baltimore, Maryland, United States
Recruiting
Brigham and Women's Hospital
Boston, Massachusetts, United States
Recruiting
Curalta Clinical Trials
Westwood, New Jersey, United States
Recruiting
Duke University Health System (Duke Health), Duke University Hospital
Durham, North Carolina, United States
Recruiting
Keystone Clinical Studies LLC, dba Flourish Research
Plymouth Meeting, Pennsylvania, United States
Withdrawn
HD Research - First Surgical Hospital
Bellaire, Texas, United States
Recruiting
University of Texas (UT); Southwestern Medical Center
Dallas, Texas, United States
Recruiting
NextStage Clinical Research, All American Orthopedics and Sports Medicine
Houston, Texas, United States
Recruiting
Futuro Clinical Trials
McAllen, Texas, United States
Recruiting
Flourish Research - San Antonio (Formerly Clinical Trials of Texas)
San Antonio, Texas, United States
Recruiting
DRx Clinical Research, LLC; South Texas Bone and Joint Institute
San Antonio, Texas, United States
Recruiting
DRx Clinical Research, LLC
St. George, Utah, United States
Recruiting
Multi-profile Hospital for Active Treatment Hearth and Brain EAD
Pleven, Bulgaria
Recruiting
Multiprofile Hospital for Active Treatment; Sveta Sofia EOOD (MBAL Sveta Sofia),
Sofia, Bulgaria
Recruiting
University Multiprofile Hospital for Active Treatment "Prof. Dr. Stoyan Kirkovich"
Stara Zagora, Bulgaria
Recruiting
Szegedi Tudomanyegyetem; Albert Szent-Gyorgyi Clinical Center
Szeged, Csongrad-Csanad, Hungary
Recruiting
Gyor-Moson-Sopron Varmegyei Egyetemi Oktato Korhaz
Győr, Győr-Moson-Sopron, Hungary
Recruiting
University of Debrecen
Debrecen, Hajdú-Bihar, Hungary
Recruiting
Semmelweis University
Budapest, Hungary
Recruiting
Kansai Rosai Hospital
Amagasaki-shi, Hyōgo, Japan
Recruiting
Yuuai Medical Center
Tomigusuku, Okinawa, Japan
Recruiting
National Hospital Organization Osaka Minami Medical Center
Kawachi-Nagano, Osaka, Japan
Recruiting
Osaka Saiseikai Nakatsu Hospital
Kita-Ku, Osaka, Japan
Recruiting
Juntendo University Hospital
Bunkyo-ku, Tokyo, Japan
Recruiting
Saga University Hospital
Saga, Japan
Recruiting
Liepajas regionala slimnica; SIA
Liepāja, Latvia
Recruiting
Rigas 2 slimnica, SIA
Riga, Latvia
Recruiting
Hospital of Traumatology and Orthopaedics
Riga, Latvia
Recruiting
ORTO Klinika
Riga, Latvia
Recruiting
Vidzemes slimnica
Valmiera, Latvia
Recruiting
Lietuvos sveikatos mokslu universiteto Kauno ligonine
Kaunas, Lithuania
Recruiting
Lietuvos sveikatos mokslu universiteto ligonine Kauno klinik
Kaunas, Lithuania
Recruiting
Vsi Klaipedos Universitetine Ligonine
Klaipėda, Lithuania
Recruiting
Szpital Specjalistyczny im. Ludwika Rydygiera w Krakowie sp. z o.o.
Krakow, Poland
Recruiting
Uniwersytecki Szpital Kliniczny nr.2 Uniwersytetu Medycznego w Lodzi
Lodz, Poland
Recruiting
Samodzieny Publiczny Zaklad Opieki Zdorowotne (SP ZOZ) Centralny Szpital Kliniczny Uniwersytetu Medycznego w Lodzi - Hematology
Lodz, Poland
Recruiting
Ortopedyczno-Rehabilitacyjny Szpital Kliniczny im. Wiktora Degi Uniwersytetu Medycznego w Poznaniu
Poznan, Poland
Recruiting
Arensia Clinics S.R.L
Bucharest, Romania
Recruiting
ARENSIA Exploratory Medicine, County Hospital Cluj-Napoca
Cluj-Napoca, Romania
Recruiting
Showing 47 of 47 sites. 46 of the 47 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.
Source: ClinicalTrials.gov record NCT07015905. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.
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