REGN7508 Versus Apixaban and Enoxaparin for Thromboprophylaxis After Total Knee Arthroplasty in Adults (ROXI-APEX)

Regeneron Pharmaceuticals

Status and phase: Enrolling; Phase 3

Conditions: Venous Thromboembolism (VTE)

Treatments: Drug: REGN7508; Drug: Enoxaparin; Drug: Placebo; Drug: Apixaban

Study type: Interventional

Funder types: Industry

Identifiers

NCT07015905

R7508-DVT-24116

2025-520478-20-00 (Registry Identifier)

Details and patient eligibility

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.

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)

Enrollment: 2,000 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion 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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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2,000 participants in 4 patient groups

IV REGN7508

Experimental group

Treatment:

Drug: REGN7508

IV Placebo, SC REGN7508

Experimental group

Treatment:

Drug: Placebo

Drug: REGN7508

IV Placebo, apixaban

Active Comparator group

Treatment:

Drug: Apixaban

Drug: Placebo

IV Placebo, enoxaparin

Active Comparator group

Treatment:

Drug: Placebo

Drug: Enoxaparin