Working… Menu

Factor Xa Inhibitor Versus Standard of Care Heparin in Hospitalized Patients With COVID-19 (XACT) (XACT)

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. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04640181
Recruitment Status : Not yet recruiting
First Posted : November 23, 2020
Last Update Posted : November 23, 2020
Information provided by (Responsible Party):
St. David's HealthCare

Brief Summary:
This study is a multicenter, randomized trial to study the potential benefit of treatments with a direct FXa inhibitor (rivaroxaban) versus standard of care dose subcutaneous low molecular weight heparin (LMWH) (Lovenox) in hospitalized subjects with COVID-19.

Condition or disease Intervention/treatment Phase
Covid19 Drug: Enoxaparin Drug: Rivaroxaban Phase 2

Detailed Description:
As clinicians learn how to better care for hospitalized COVID-19 patients, the clinical picture of a hypercoagulable state with abnormal blood clotting has emerged. Fulminant heart, lung, kidney, and liver failure are hallmarks of COVID-19 non-survivors and have been associated with abnormal blood coagulation parameters, such as elevated D-Dimer levels. The current standard of care using prophylactic levels of subcutaneous heparin has not significantly mitigated the risk of patients entering a hypercoagulable state, however the dysregulated thrombotic and inflammatory events that drive poor outcomes in many COVID-19 patients may be amenable to early treatment with a factor Xa (FXa) inhibitor. The purpose of this study is to study the potential benefit of treatments with a direct FXa inhibitor (rivaroxaban) versus standard of care dose subcutaneous LMWH (Lovenox) in hospitalized subjects with COVID-19.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 150 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: Open-label Multicenter Prospective Randomized Trial in hospitalized patients with severe acute respiratory syndrome (SARS)-CoV-2 infection. Patients will be randomized 1:1 to subcutaneous enoxaparin (Lovenox) versus rivaroxaban after hospitalization, with the exact dosing is based on an adaptive strategy.
Masking: None (Open Label)
Masking Description: Open label
Primary Purpose: Treatment
Official Title: A Phase 2-3, Multi-Center, Randomized Trial to Study the Potential Benefit of Factor Xa Inhibitor (Rivaroxaban) Versus Standard of Care Low Molecular Weight Heparin (Lovenox) in Hospitalized Patients With COVID-19 (XACT)
Estimated Study Start Date : December 1, 2020
Estimated Primary Completion Date : June 30, 2021
Estimated Study Completion Date : July 31, 2021

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Blood Thinners

Arm Intervention/treatment
Active Comparator: Adaptive Dosing: Enoxaparin
  • Low 40mg subcutaneous (SQ) daily, or
  • Intermediate 40mg SQ q12 hours, or
  • Therapeutic 1mg/kg SQ q12 hours
Drug: Enoxaparin
Subcutaneous enoxaparin While hospitalized only.

Active Comparator: Adaptive Dosing: Rivaroxaban
  • Low 10mg po daily
  • Intermediate 10mg po daily
  • Therapeutic 20mg po daily
Drug: Rivaroxaban
Oral rivaroxaban While hospitalized and through discharge for a total of 28 days.

Primary Outcome Measures :
  1. Death or 30-day all cause mortality [ Time Frame: 30 days ]
  2. Mechanical ventilation, intubation [ Time Frame: 30 days ]
  3. Transfer to an ICU setting [ Time Frame: 30 days ]

Secondary Outcome Measures :
  1. New requirement for hemodialysis (HD) or continuous renal replacement therapy (CRRT) or extracorporeal membrane oxygenation (ECMO) [ Time Frame: 30 days ]
  2. New thrombotic events [ Time Frame: 30 days ]
  3. Major bleeding event [ Time Frame: 30 days ]
  4. Time to recovery (defined as no limitation or minor limitation in activity level or hospitalized but require no oxygen) [ Time Frame: 30 days ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 100 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients age 18-100 admitted to hospital with laboratory-confirmed SARS-CoV-2 infection
  • Not be intubated or mechanically ventilated or imminently at risk for same or ICU admission within 24 hours of enrollment.
  • Not be admitted for central nervous system (CNS) diagnosis
  • Not have a current history of a condition requiring full therapeutic anticoagulation such as venous thromboembolism, atrial fibrillation.

Exclusion Criteria:

Medical Conditions

  • Life expectancy of less than 6 months
  • Active or recent gastrointestinal bleeding in the past 6 months
  • Intracranial bleeding in the past 6 months
  • Major trauma or head trauma in the past 2 months
  • Major surgery in the past 2 months or planned within 2 weeks after completion of the study
  • Recent spinal or epidural procedures in the past 2 weeks
  • Ischemic stroke in the past 2 weeks
  • History of intracranial neoplasm, arteriovenous malformation or aneurysm
  • History of acquired or spontaneous impairment of hemostasis such as but not limited to hemophilia, idiopathic thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), von Willebrand disease
  • Allergy to heparin or rivaroxaban or any factor Xa inhibitors, including a history of heparin-induced thrombocytopenia
  • History of antiphospholipid syndrome
  • End-stage renal failure requiring dialysis
  • Valvular heart disease requiring chronic anticoagulation
  • History of atrial fibrillation, atrial flutter or venous thromboembolic event (VTE) currently requiring anticoagulation
  • History of solid organ transplant requiring immunosuppressant therapy
  • Cancer requiring ongoing anticoagulation
  • History of cirrhosis or liver failure, hepatorenal syndrome
  • History of baseline bronchiectasis
  • History of systemic lupus erythematosus or other autoimmune diseases requiring immunosuppressant therapy.

Vital signs

  • Uncontrolled hypertension: systolic blood pressure (SBP) > 180 mm Hg or diastolic blood pressure (DBP) > 105mm Hg. Subjects who have a transient, higher blood pressure elevation (SBP 180-200 mm Hg) may enter the study if a repeat confirmation is back in range prior to enrollment.


  • PT INR > 2.0.
  • Platelet < 90 10^3/µL
  • Total bilirubin > 3.0 mg/dL
  • Hemoglobin < 9.0 g/dL
  • Urine with gross hematuria (not due to menses)
  • Estimated glomerular filtration rate (GFR) less than 30 mL/min calculated with the Cockcroft-Gault formula


  • Patients on dual anti-platelet therapy
  • Patients taking hypoxia-inducible factor prolyl hydroxylase inhibitors (such as roxadustat.)
  • Erythropoiesis-stimulating agents (such as epoetin alfa, darbepoetin alfa)

Other COVID-19 drug studies or trials

  • Any COVID19 vaccination trials
  • Experimental COVID drug trial except for treatment(s) that has become accepted standard of care.

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): NCT04640181

Layout table for location contacts
Contact: Matt Cowperthwaite, PhD 512-544-2626
Contact: Theresa Pham, MD

Sponsors and Collaborators
St. David's HealthCare
Layout table for investigator information
Principal Investigator: Edward Chafizadeh, MD Cardio Texas, PLLC
Principal Investigator: Theresa Pham, MD PPD Austin
Additional Information:
Layout table for additonal information
Responsible Party: St. David's HealthCare Identifier: NCT04640181    
Other Study ID Numbers: 2020-001708-41
First Posted: November 23, 2020    Key Record Dates
Last Update Posted: November 23, 2020
Last Verified: November 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: Yes
Keywords provided by St. David's HealthCare:
Additional relevant MeSH terms:
Layout table for MeSH terms
Factor Xa Inhibitors
Serine Proteinase Inhibitors
Protease Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Fibrinolytic Agents
Fibrin Modulating Agents