Venous Thromboembolism (VTE)Phase 3ROXI-APEXNCT07015905
REGN7508 Versus Apixaban and Enoxaparin for Thromboprophylaxis After Total Knee Arthroplasty in Adults
A Phase 3 study testing REGN7508, Apixaban and Enoxaparin in people with Venous Thromboembolism (VTE), run by Regeneron Pharmaceuticals at 47 sites in 8 countries.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Venous Thromboembolism (VTE)
- What is being tested?
- REGN7508, Apixaban and Enoxaparin
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 2,000 participants
- Where
- 47 sitesin 8 countries
- Study dates
- 25 Jun 2025to 12 May 2027
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
- Note: Other protocol-defined Inclusion/ Exclusion Criteria apply
Trial locations and contacts
47 sites in 8 countries. Contact the study team or a site near you to ask about taking part.
47 sites in 8 countries
United States20 sites, 18 recruiting
- Recruiting
Sinai Hospital of Baltimore, Inc.
Baltimore, Maryland, 21215
- Recruiting
HD Research - First Surgical Hospital
Bellaire, Texas, 77401
- Recruiting
Brigham and Women's Hospital
Boston, Massachusetts, 02115
- Recruiting
University of Texas (UT); Southwestern Medical Center
Dallas, Texas, 75390
- Recruiting
Delray Physician Care Center
Delray Beach, Florida, 33445
- Recruiting
Duke University Health System (Duke Health), Duke University Hospital
Durham, North Carolina, 27710
- Recruiting
Denver Metro Orthopedics, P.C. Englewood Location
Englewood, Colorado, 80113
- Completed
NextStage Clinical Research, All American Orthopedics and Sports Medicine
Houston, Texas, 77058
- Recruiting
Futuro Clinical Trials
McAllen, Texas, 78501
- Recruiting
Bioresearch Partner
Miami, Florida, 33175
- Recruiting
Sacred Heart Health System Inc
Pensacola, Florida, 32504
- Withdrawn
Keystone Clinical Studies LLC, dba Flourish Research
Plymouth Meeting, Pennsylvania, 19462
- Recruiting
CARI Clinical Trials
Riverside, California, 92504
- Recruiting
Flourish Research - San Antonio (Formerly Clinical Trials of Texas)
San Antonio, Texas, 78229
- Recruiting
DRx Clinical Research, LLC; South Texas Bone and Joint Institute
San Antonio, Texas, 78249
- Recruiting
Gulfcoast Research Institute
Sarasota, Florida, 34232
- Recruiting
Shoals Medical Trials, Inc.
Sheffield, Alabama, 35660
- Recruiting
DRx Clinical Research, LLC
St. George, Utah, 84770
- Recruiting
Phoenix Clinical Research
Tamarac, Florida, 33321
- Recruiting
Curalta Clinical Trials
Westwood, New Jersey, 07675
Japan6 sites, 6 recruiting
- Recruiting
Kansai Rosai Hospital
Amagasaki-shi, Hyōgo, 660-8511
- Recruiting
Juntendo University Hospital
Bunkyo-ku, Tokyo, 113-8431
- Recruiting
National Hospital Organization Osaka Minami Medical Center
Kawachi-Nagano, Osaka, 586-8521
- Recruiting
Osaka Saiseikai Nakatsu Hospital
Kita-Ku, Osaka, 530-0012
- Recruiting
Saga University Hospital
Saga, 849-8501
- Recruiting
Yuuai Medical Center
Tomigusuku, Okinawa, 901-0224
Latvia5 sites, 5 recruiting
- Recruiting
Liepajas regionala slimnica; SIA
Liepāja, LV-3414
- Recruiting
Rigas 2 slimnica, SIA
Riga, LV-1004
- Recruiting
Hospital of Traumatology and Orthopaedics
Riga, LV-1005
- Recruiting
ORTO Klinika
Riga, LV-1005
- Recruiting
Vidzemes slimnica
Valmiera, LV-4201
Hungary4 sites, 4 recruiting
- Recruiting
Semmelweis University
Budapest, 1082
- Recruiting
University of Debrecen
Debrecen, Hajdú-Bihar, 4031
- Recruiting
Gyor-Moson-Sopron Varmegyei Egyetemi Oktato Korhaz
Győr, Győr-Moson-Sopron, 9024
- Recruiting
Szegedi Tudomanyegyetem; Albert Szent-Gyorgyi Clinical Center
Szeged, Csongrad-Csanad, 6725
Poland4 sites, 4 recruiting
- Recruiting
Szpital Specjalistyczny im. Ludwika Rydygiera w Krakowie sp. z o.o.
Krakow, 31-826
- Recruiting
Uniwersytecki Szpital Kliniczny nr.2 Uniwersytetu Medycznego w Lodzi
Lodz, 90-549
- Recruiting
Samodzieny Publiczny Zaklad Opieki Zdorowotne (SP ZOZ) Centralny Szpital Kliniczny Uniwersytetu Medycznego w Lodzi - Hematology
Lodz, 92-213
- Recruiting
Ortopedyczno-Rehabilitacyjny Szpital Kliniczny im. Wiktora Degi Uniwersytetu Medycznego w Poznaniu
Poznan, 61-545
Bulgaria3 sites, 2 recruiting
- Recruiting
Multi-profile Hospital for Active Treatment Hearth and Brain EAD
Pleven, 5804
- Recruiting
Multiprofile Hospital for Active Treatment; Sveta Sofia EOOD (MBAL Sveta Sofia),
Sofia, 1404
- Withdrawn
University Multiprofile Hospital for Active Treatment "Prof. Dr. Stoyan Kirkovich"
Stara Zagora, 6003
Lithuania3 sites, 3 recruiting
- Recruiting
Lietuvos sveikatos mokslu universiteto Kauno ligonine
Kaunas, LT-47144
- Recruiting
Lietuvos sveikatos mokslu universiteto ligonine Kauno klinik
Kaunas, LT-50161
- Recruiting
Vsi Klaipedos Universitetine Ligonine
Klaipėda, LT-92288
Romania2 sites, 2 recruiting
- Recruiting
Arensia Clinics S.R.L
Bucharest, 011658
- Recruiting
ARENSIA Exploratory Medicine, County Hospital Cluj-Napoca
Cluj-Napoca, 400006
About this study
Official title: 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)
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)
- Conditions
- Venous Thromboembolism (VTE)
- Being tested
- REGN7508, Apixaban, Enoxaparin, Placebo
- Keywords
- Unilateral Total Knee Arthroplasty (TKA), Factor XI (FXI)
- Medical subject headings
- Venous Thromboembolism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
REGN7508Drug
Also called cenvacibart
Administered per the protocol
ApixabanDrug
Administered per the protocol
EnoxaparinDrug
Also called Inhixa
Administered per the protocol
PlaceboDrug
Administered per the protocol
| Study group | Role | What they receive |
|---|---|---|
| IV REGN7508 | Experimental | Not described Receives: Drug: REGN7508 |
| IV Placebo, SC REGN7508 | Experimental | Not described Receives: Drug: REGN7508; Drug: Placebo |
| IV Placebo, apixaban | Active comparator | Not described Receives: Drug: Apixaban; Drug: Placebo |
| IV Placebo, enoxaparin | Active comparator | Not described Receives: Drug: Enoxaparin; Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of the composite endpoint of asymptomatic or symptomatic Venous Thromboembolism (VTE) [including VTE-related death]
Measured: 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)
Measured: Through day 12 visit, approximately 14 days
Incidence of confirmed symptomatic Deep Venous Thrombosis (DVT)
Measured: Through day 12 visit, approximately 14 days
Incidence of confirmed Pulmonary Embolism (PE)
Measured: Through day 12 visit, approximately 14 days
Incidence of VTE-related death
Measured: Through day 12 visit, approximately 14 days
Time-to-first event of confirmed symptomatic DVT
Measured: Through day 12 visit, approximately 14 days
Time-to-first event of confirmed PE
Measured: Through day 12 visit, approximately 14 days
Time to VTE-related death
Measured: Through day 12 visit, approximately 14 days
Incidence of the composite endpoint of major and Clinically Relevant Non-Major (CRNM) bleeding
Measured: Through day 12 visit, approximately 14 days
Incidence of the composite endpoint of asymptomatic or symptomatic VTE (including VTE-related death)
Measured: Through day 12 visit, approximately 14 days
Incidence of minor bleeding
Measured: Through day 12 visit, approximately 14 days
Incidence of Treatment Emergent Adverse Events (TEAEs)
Measured: Approximately day 90
Occurrence of Anti-Drug Antibodies (ADA) to REGN7508
Measured: Approximately day 90
Magnitude of ADA to REGN7508
Measured: Approximately day 90
Concentrations of REGN7508
Measured: Approximately day 90
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2025
- Study start25 Jun 2025
- Primary completion20 Feb 2027 (estimated)
- Study completion12 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Venous Thromboembolism (VTE)Studies of the same condition, open and under way.
- More trials run by Regeneron PharmaceuticalsThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 2,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Regeneron Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Clinical Trial Management, Study director, Regeneron Pharmaceuticals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07015905
- Sponsor's protocol ID
- R7508-DVT-24116
- Other IDs
- 2025-520478-20-00, 2025
- Acronym
- ROXI-APEX
- Status last verified
- Oct 2026
- First submitted
- 3 Jun 2025
- Last updated
- 8 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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