REGN7508 Versus Acetylsalicylic Acid (ASA) for Venous Thromboprophylaxis After Total Knee Arthroplasty in Adult Participants

NCT07213778
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Phase
Phase 3
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Recruitment status
Recruiting
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Participants
2,000
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Lead sponsor
Regeneron Pharmaceuticals
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Start date
2025-11-24
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Number of sites
34
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Summary
This study is researching an experimental drug called REGN7508 (called "study drug") and how it compares against another treatment called Acetylsalicylic Acid (ASA). 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 compared to acetylsalicylic acid. 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)
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Acronym
ROXI-ASPEN
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Short title
REGN7508 Versus Acetylsalicylic Acid (ASA) for Venous Thromboprophylaxis After Total Knee Arthroplasty in Adult Participants
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Official title
A Phase 3, Multicenter, Double-Blinded, Randomized Study to Evaluate REGN7508, a Factor XI Monoclonal Antibody, Versus Acetylsalicylic Acid for Prophylaxis of Symptomatic Venous Thromboembolism After Elective Total Knee Arthroplasty (ROXI-ASPEN)
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Control arm
Active comparator
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Registry reports results
No
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Listing at source
Listed
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Recruitment status
Recruiting
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Phase
Phase 3
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Study type
Interventional
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Completion date
2027-07-16
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First posted
2025-10-09
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Registry last updated
2026-08-19
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Primary completion date
2027-05-17
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Start date
2025-11-24
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Participants
2,000
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Participant count basis
Estimated
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Planned participants
2,000
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Protocol amendments
1
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Number of sites
34
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Data monitoring committee
Yes
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Registry sponsor category
Industry
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Lead sponsor
Regeneron Pharmaceuticals
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Source registry
ClinicalTrials.gov
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Registry ID
NCT07213778
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ClinicalTrials.gov ID
NCT07213778
clinicaltrials.gov
Registry record
Open registry record
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Allocation
Randomised
Model
Parallel groups
Purpose
Treatment
Masking
Quadruple masking
Masked roles
Participants, Care providers, Investigators, Outcome assessors
Sources for study design
clinicaltrials.gov

  1. Incidence of the composite endpoint of symptomatic VTE and all-cause death

    Timeframe: Through day 30 visit

  1. Time to first event of the composite endpoint of symptomatic VTE and all-cause death

    Timeframe: Through day 30 visit

  2. Incidence of confirmed symptomatic Deep Vein Thrombosis (DVT)

    Timeframe: Through day 30 visit

  3. Incidence of confirmed Pulmonary Embolism (PE)

    Timeframe: Through day 30 visit

  4. Incidence of all-cause death

    Timeframe: Through day 30 visit

  5. Time to first event of the confirmed symptomatic DVT

    Timeframe: Through day 30 visit

  6. Time to first event of the confirmed PE

    Timeframe: Through day 30 visit

  7. Time to the all-cause death

    Timeframe: Through day 30 visit

  8. Incidence of the composite endpoint of major bleeding and Clinically Relevant Non-Major (CRNM) bleeding

    Timeframe: Through day 30 visit

  9. Incidence of minor bleeding

    Timeframe: Through day 30 visit

  10. Incidence of Treatment-Emergent Adverse Events (TEAEs)

    Timeframe: Through day 90 visit

  11. Severity of TEAEs

    Timeframe: Through day 90 visit

  12. Incidence of Anti-drug Antibody (ADA) to REGN7508

    Timeframe: Through day 90 visit

  13. Magnitude of ADA to REGN7508

    Timeframe: Through day 90 visit

  14. Concentrations of REGN7508

    Timeframe: Through day 90 visit

Sources for outcomes
clinicaltrials.gov

Sex
All
Age groups
Adults, Older adults
Minimum age
18 Years
Healthy volunteers
No

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

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; history of intracranial or intraocular bleeding, excessive operative or post-operative bleeding, and traumatic spinal or epidural anesthesia; history of bleeding diathesis (eg, hemophilia A or B, von Willebrand's Factor deficiency)
  3. History of thromboembolic disease or thrombophilia
  4. History of platelet dysfunction
  5. Has received or plans to receive preoperative enoxaparin on the day prior to TKA surgery

Note: Other protocol-defined Inclusion/ Exclusion criteria apply

Sources for eligibility
clinicaltrials.gov

  • Horizon Clinical ResearchLa Mesa, United StatesRecruiting
  • Eisenhower Medical CenterRancho Mirage, United StatesRecruiting
  • Sky Ridge Medical CenterLone Tree, United StatesRecruiting
  • South Florida Joint Replacement CenterDeerfield Beach, United StatesRecruiting
  • Medical Research of Westchester - MPLUS Research NetworkMiami, United StatesRecruiting
  • Larkin Community Hospital South MiamiSouth Miami, United StatesRecruiting
  • Phoenix Clinical ResearchTamarac, United StatesRecruiting
  • Endeavor HealthSkokie, United StatesRecruiting
  • The Orthopaedic Research Foundation, Inc.Indianapolis, United StatesRecruiting
  • NextStage Clinical Research, St. Francis Medical ParkWichita, United StatesRecruiting
  • Velocity Clinical Research, AnnapolisAnnapolis, United StatesRecruiting
  • Sinai Hospital of Baltimore, Inc.Baltimore, United StatesRecruiting
  • Tufts Medical CenterBoston, United StatesRecruiting
  • Boston Medical CenterBoston, United StatesRecruiting
  • Holy Name Medical CenterTeaneck, United StatesRecruiting
  • University of Rochester Medical CenterRochester, United StatesRecruiting
  • Eximia Equihealth Research-Raleigh. LLCRaleigh, United StatesRecruiting
  • The Vein and Vascular Center at Raleigh RadiologyRaleigh, United StatesRecruiting
  • Coastal Vascular Institute, PAWilmington, United StatesRecruiting
  • University of CincinnatiCincinnati, United StatesRecruiting
  • The Ohio State University Wexner Medical CenterColumbus, United StatesRecruiting
  • Ohio Clinical TrialsColumbus, United StatesRecruiting
  • University of PittsburghPittsburgh, United StatesRecruiting
  • HD Research - Memorial Hermann VillageHouston, United StatesRecruiting
  • NextStage Clinical Research, All American Orthopedics and Sports MedicineHouston, United StatesRecruiting

And 9 more, listed on the interactive page.

Sources for sites
clinicaltrials.gov

  • 2025
  • 2025-520479-25-00
Sources for references
clinicaltrials.gov

Related records

Drugs (2)

Lead sponsors (1)

Conditions (2)

Targets (4)