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Factor Xa Inhibitor, PRT054021, Against Enoxaparin for the Prevention of Venous Thromboembolic Events (EXPERT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00375609
Recruitment Status : Completed
First Posted : September 13, 2006
Results First Posted : December 15, 2017
Last Update Posted : January 23, 2018
Information provided by (Responsible Party):
Portola Pharmaceuticals

Brief Summary:
Randomized study of PRT054021 40 mg and 15 mg bid vs. enoxaparin 30 mg q12h for the prophylaxis of venous thromboembolic events after unilateral knee replacement surgery.

Condition or disease Intervention/treatment Phase
Thromboembolism Drug: Betrixaban Drug: Enoxaparin Phase 2

Detailed Description:
Approximately 200 patients undergoing unilateral knee replacement will be entered into the study and randomized to receive either enoxaparin 30 mg sq bid, PRT054021 15 mg po bid, or PRT054021 40 mg po bid for 10 to 14 days, at which time patients will undergo venography.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 215 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Evaluation of the Factor Xa Inhibitor, PRT054021, Against Enoxaparin in a Randomized Trial for the Prevention of Venous Thromboembolic Events After Unilateral Total Knee Replacement (EXPERT)
Study Start Date : May 2006
Actual Primary Completion Date : January 2007
Actual Study Completion Date : February 2007

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Betrixaban 15 mg
Betrixaban 15 mg oral twice daily for 10 to 14 days
Drug: Betrixaban

Experimental: Betrixaban 40 mg
Betrixaban 40 mg oral twice daily for 10 to 14 days
Drug: Betrixaban

Experimental: Enoxaparin
Enoxaparin 30 mg administered subcutaneously every 12 hours for 10 to 14 days
Drug: Enoxaparin
Administered subcutaneously
Other Name: Lovenox

Primary Outcome Measures :
  1. Incidence of Adjudicated Venous Thromboembolism (VTE) [ Time Frame: Through Day 10-14 following TKR surgery, at time of mandatory venogram ]
    Incidence of adjudicated venous thromboembolism (VTE) through Day 10-14 following TKR where VTE is defined as DVT (proximal and/or distal) and/or PE. Patients were evaluated for VTE daily while hospitalized and were contacted every 2 to 4 days after discharge and before the day of the mandatory venogram to monitor for study endpoints

  2. Incidence of Adjudicated Overt Bleeding Events: Primary Safety Endpoint [ Time Frame: Through follow-up at approximately 6 (±2) weeks after TKR surgery ]
    The incidence of adjudicated major and clinical relevant non-major bleeding. Major bleeding was defined as fatal, involving vital organs, requiring additional surgery or a new therapeutic procedure, or a bleeding index >=2. Bleeding Index was defined as the number of units of packed red blood cells or whole blood transfused plus the haemoglobin values before the bleeding episode minus the haemoglobin values after the bleed had stabilized (in g/dL)

Secondary Outcome Measures :
  1. Incidence of Adjudicated Pulmonary Embolism (PE) and All Deep Vein Thrombosis (DVT) (Proximal and Distal) [ Time Frame: At follow-up at approximately 6 (±2) weeks after TKR surgery ]
    Incidence of adjudicated pulmonary embolism (PE) and all deep vein thrombosis (DVT) (proximal and distal) through the time of venography on Day 10 to 14 and at follow-up at approximately 6 (±2) weeks after TKR surgery

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • • The subject has undergone elective primary unilateral TKR (not unicompartmental).


  • The subject is between the ages of 18 and 75 years.
  • If the subject is a woman, she is without reproductive potential (postmenopausal for >2 years or after hysterectomy).
  • The subject weighs between 50 kg (110 lbs) and 120 kg (265 lbs). Laboratory and Procedures
  • The subject is willing and able to undergo unilateral venography. Medications
  • The subject is willing and able to self-inject enoxaparin or receive injections q12h by a caregiver.

Ethical • The subject is able to read and give written informed consent and has signed an informed consent form approved by the Investigator's IRB/IEC.

Exclusion Criteria:

  • Disease Related

    • Major medical and/or surgical condition which may impair oral drug absorption or metabolism.
    • Immobilization for 3 or more days before surgery.
    • History (including family history) or symptoms of a congenital or acquired bleeding disorder or vascular malformation; or a history of intracranial, retroperitoneal, or intraocular bleeding within the last 6 months; or is felt to be at high risk for bleeding for other reasons.
    • Gastrointestinal bleeding within 90 days before surgery or endoscopically verified ulcer disease within 30 days before surgery.
    • Indwelling intrathecal or epidural catheter during the prophylaxis period (except for epidural catheter if removed after surgery); or unusual difficulty in administering spinal or epidural anesthesia (eg, 3 or more attempts, "traumatic taps").
    • Major surgery, ischemic stroke, or myocardial infarction within 3 months before Screening.
    • Uncontrolled hypertension defined as systolic blood pressure (SBP) > 180 mmHg or diastolic blood pressure (DBP) >105 mmHg.
    • Hypotension defined as SBP <95 mmHg.
    • Evidence at Screening of symptomatic congestive heart failure requiring treatment.
    • Chronic atrial fibrillation treated with oral anticoagulants, recurrent atrial arrhythmia(s) or a history of recurrent ventricular tachycardia.

Laboratory and Procedures

• Evidence at Screening of: platelet count <100,000/mm3 potassium <3.5 mEq/L hemoglobin concentration <10 g/dL or hematocrit <30% serum ALT or AST >2 times ULN serum creatinine >2.0 mg/dL (180 µm/L)

  • Contraindication to venography, including to iodinated contrast medium
  • QTc on Screening ECG >450 msec and/or a personal or family history of "Long QT Syndrome".


  • Contraindication to anticoagulation for VTE prophylaxis, including a contraindication to receiving heparin or heparinoids.
  • Administration of the following drugs within 7 days before TKR: thrombolytic agents, anticoagulants and/or anti-platelet agents (eg, heparins, warfarin, dipyridamole, sulfinpyrazone, ticlopidine, dextran, clopidogrel). Aspirin up to 325 mg once daily and NSAIDs are allowed but discouraged.
  • Use of class III antiarrhythmics drugs (eg, dofetilide, ibutilide, amiodarone, bretylium, sotalol) within 30 days prior to TKR.


  • Participation in any investigational drug study 30 days prior to enrollment is prohibited. Participation in a device trial prior to enrollment is acceptable.
  • Any condition which could interfere with or for which the treatment of might interfere with the conduct of the study, or which would, in the opinion of the Investigator, unacceptably increase the risk of the subject's participation in the study. This would include, but is not limited to alcoholism, drug dependency or abuse, psychiatric disease, epilepsy or any unexplained blackouts.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00375609

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Canada, Quebec
Montreal General Hospital
Montreal, Quebec, Canada, H3Y 3B8
Sponsors and Collaborators
Portola Pharmaceuticals
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Responsible Party: Portola Pharmaceuticals Identifier: NCT00375609    
Other Study ID Numbers: PRT05-003
First Posted: September 13, 2006    Key Record Dates
Results First Posted: December 15, 2017
Last Update Posted: January 23, 2018
Last Verified: July 2017
Keywords provided by Portola Pharmaceuticals:
Prevention of Venous Thromboembolism
Additional relevant MeSH terms:
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Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Factor Xa Inhibitors
Serine Proteinase Inhibitors
Protease Inhibitors
Enzyme Inhibitors