REGN7508 Versus Apixaban and Enoxaparin for Thromboprophylaxis After Total Knee Arthroplasty in Adults
ROXI-APEX
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)
2 other identifiers
interventional
2,000
8 countries
44
Brief Summary
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)
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_3
Started Jun 2025
44 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
June 3, 2025
CompletedFirst Posted
Study publicly available on registry
June 11, 2025
CompletedStudy Start
First participant enrolled
June 25, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
February 20, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
May 12, 2027
May 6, 2026
May 1, 2026
1.7 years
June 3, 2025
May 4, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Incidence of the composite endpoint of asymptomatic or symptomatic Venous Thromboembolism (VTE) [including VTE-related death]
Through day 12 visit, approximately 14 days
Secondary Outcomes (14)
Time-to-first event of the composite endpoint of asymptomatic or symptomatic VTE (including VTE-related death)
Through day 12 visit, approximately 14 days
Incidence of confirmed symptomatic Deep Venous Thrombosis (DVT)
Through day 12 visit, approximately 14 days
Incidence of confirmed Pulmonary Embolism (PE)
Through day 12 visit, approximately 14 days
Incidence of VTE-related death
Through day 12 visit, approximately 14 days
Time-to-first event of confirmed symptomatic DVT
Through day 12 visit, approximately 14 days
- +9 more secondary outcomes
Study Arms (4)
IV REGN7508
EXPERIMENTALIV Placebo, SC REGN7508
EXPERIMENTALIV Placebo, apixaban
ACTIVE COMPARATORIV Placebo, enoxaparin
ACTIVE COMPARATORInterventions
Administered per the protocol
Eligibility Criteria
You may qualify if:
- Is undergoing a primary elective unilateral TKA
- Is in good health based on laboratory safety testing as described in the protocol
- Body weight ≤130 kg at screening visit as described in the protocol
You may not qualify if:
- 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
- History of bleeding in the 6 months prior to randomization requiring hospitalization or transfusion as described in the protocol
- History of thromboembolic disease or thrombophilia
- History of major surgery, including brain, spinal, or ocular, or major trauma within approximately the past 6 months prior to randomization
- Has an estimated Glomerular Filtration Rate (GFR) of \<30 mL/min/1.73 m2 at the screening visit as described in the protocol
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (44)
Shoals Medical Trials, Inc.
Sheffield, Alabama, 35660, United States
CARI Clinical Trials
Riverside, California, 92504, United States
Denver Metro Orthopedics, P.C. Englewood Location
Englewood, Colorado, 80113, United States
Delray Physician Care Center
Delray Beach, Florida, 33445, United States
Bioresearch Partner
Miami, Florida, 33175, United States
Sacred Heart Health System Inc
Pensacola, Florida, 32504, United States
Gulfcoast Research Institute
Sarasota, Florida, 34232, United States
Phoenix Clinical Research
Tamarac, Florida, 33321, United States
Sinai Hospital of Baltimore, Inc.
Baltimore, Maryland, 21215, United States
Brigham and Women's Hospital
Boston, Massachusetts, 02115, United States
Curalta Clinical Trials
Westwood, New Jersey, 07675, United States
Duke University Health System (Duke Health), Duke University Hospital
Durham, North Carolina, 27710, United States
Keystone Clinical Studies LLC, dba Flourish Research
Plymouth Meeting, Pennsylvania, 19462, United States
HD Research - First Surgical Hospital
Bellaire, Texas, 77401, United States
University of Texas (UT); Southwestern Medical Center
Dallas, Texas, 75390, United States
NextStage Clinical Research, All American Orthopedics and Sports Medicine
Houston, Texas, 77058, United States
Futuro Clinical Trials
McAllen, Texas, 78501, United States
Flourish Research - San Antonio (Formerly Clinical Trials of Texas)
San Antonio, Texas, 78229, United States
DRx Clinical Research, LLC
St. George, Utah, 84770, United States
Multi-profile Hospital for Active Treatment Hearth and Brain EAD
Pleven, 5804, Bulgaria
Multiprofile Hospital for Active Treatment; Sveta Sofia EOOD (MBAL Sveta Sofia),
Sofia, 1404, Bulgaria
University Multiprofile Hospital for Active Treatment "Prof. Dr. Stoyan Kirkovich"
Stara Zagora, 6003, Bulgaria
Gyor-Moson-Sopron Varmegyei Egyetemi Oktato Korhaz
Győr, Győr-Moson-Sopron, 9024, Hungary
University of Debrecen
Debrecen, Hajdú-Bihar, 4031, Hungary
Semmelweis University
Budapest, 1082, Hungary
Kansai Rosai Hospital
Amagasaki-shi, Hyōgo, 660-8511, Japan
Yuuai Medical Center
Tomigusuku, Okinawa, 901-0224, Japan
National Hospital Organization Osaka Minami Medical Center
Kawachi-Nagano, Osaka, 586-8521, Japan
Osaka Saiseikai Nakatsu Hospital
Kita-Ku, Osaka, 530-0012, Japan
Juntendo University Hospital
Bunkyo-ku, Tokyo, 113-8431, Japan
Saga University Hospital
Saga, 849-8501, Japan
Liepajas regionala slimnica; SIA
Liepāja, LV-3414, Latvia
Rigas 2 slimnica, SIA
Riga, LV-1004, Latvia
Hospital of Traumatology and Orthopaedics
Riga, LV-1005, Latvia
ORTO Klinika
Riga, LV-1005, Latvia
Vidzemes slimnica
Valmiera, LV-4201, Latvia
Lietuvos sveikatos mokslu universiteto Kauno ligonine
Kaunas, LT-47144, Lithuania
Lietuvos sveikatos mokslu universiteto ligonine Kauno klinik
Kaunas, LT-50161, Lithuania
Vsi Klaipedos Universitetine Ligonine
Klaipėda, LT-92288, Lithuania
Szpital Specjalistyczny im. Ludwika Rydygiera w Krakowie sp. z o.o.
Krakow, 31-826, Poland
Uniwersytecki Szpital Kliniczny nr.2 Uniwersytetu Medycznego w Lodzi
Lodz, 90-549, Poland
Samodzieny Publiczny Zaklad Opieki Zdorowotne (SP ZOZ) Centralny Szpital Kliniczny Uniwersytetu Medycznego w Lodzi - Hematology
Lodz, 92-213, Poland
Arensia Clinics S.R.L
Bucharest, 011658, Romania
ARENSIA Exploratory Medicine, County Hospital Cluj-Napoca
Cluj-Napoca, 400006, Romania
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- STUDY DIRECTOR
Clinical Trial Management
Regeneron Pharmaceuticals
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- RANDOMIZED
- Masking
- DOUBLE
- Who Masked
- INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
June 3, 2025
First Posted
June 11, 2025
Study Start
June 25, 2025
Primary Completion (Estimated)
February 20, 2027
Study Completion (Estimated)
May 12, 2027
Last Updated
May 6, 2026
Record last verified: 2026-05
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, ICF, CSR, 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, has made results publicly available (e.g., scientific publication, scientific conference, clinical trial registry), has the legal authority to share the data, and has 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
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