NCT07015905 · Regeneron Pharmaceuticals
REGN7508 Versus Apixaban and Enoxaparin for Thromboprophylaxis After Total Knee Arthroplasty in Adults
(ROXI-APEX)
What this study is about
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.
View original scientific description
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.
Interventions
DRUG
REGN7508
Administered per the protocol
DRUG
Apixaban
Administered per the protocol
DRUG
Enoxaparin
Administered per the protocol
DRUG
Placebo
Administered per the protocol
Primary outcome measures
Incidence of the composite endpoint of asymptomatic or symptomatic Venous Thromboembolism (VTE) [including VTE-related death]
Time frame: Through day 12 visit, approximately 14 days
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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
- 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
Where
- Sheffield, Alabama
- Riverside, California
- Englewood, Colorado
- Delray Beach, Florida
- Miami, Florida
- Pensacola, Florida
- Sarasota, Florida
- Tamarac, Florida
- Baltimore, Maryland
- Boston, Massachusetts
- Westwood, New Jersey
- Durham, North Carolina
And 7 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 13, 2026 · Source of record for eligibility and locations