Rivaroxaban for Treatment of Patients With Suspected or Confirmed Heparin-Induced Thrombocytopenia

Study Overview
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Brief Summary
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Heparin is an anticoagulant (blood thinner) that is commonly used to treat patients with heart attacks and patients with blood clots in their legs or lungs (venous thrombosis). Some patients develop an allergic reaction to heparin, a condition called heparin-induced thrombocytopenia (HIT). HIT makes blood clot, which is the opposite of what heparin was designed to do. These blood clots can lead to heart attacks, strokes, limb amputations, and death. The objective of this 200 patient study is to determine if a new blood thinner called rivaroxaban (Xarelto) can be used to treat HIT. Rivaroxaban can be taken by mouth, does not require blood testing, and had a low risk of bleeding when it was used to treat blood clots in other clinical trials. If this study shows that rivaroxaban can be used to treat HIT, there will be two very important benefits. For patients with HIT, the benefit will be having a safe, and easy-to-use drug to protect them from developing further life or limb-threatening blood clots. For the Canadian health care system, the benefit will be having a drug that is much less expensive than the drugs currently used to treat HIT.

Detailed Description
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Consecutive adult patients with an intermediate or high clinical probability for HIT (according to the clinical prediction rule called the 4T's Score) will receive rivaroxaban 15 mg bid while awaiting confirmation or exclusion of HIT by the local laboratory assay. Patients who are confirmed to have HIT by the local laboratory assay will continue to receive rivaroxaban 15 mg bid until their platelet count ≥ 150 or until end of study (Day 30). At the time of platelet count recovery (typically 4-7 days), they will be transitioned to a maintenance dose of rivaroxaban (20 mg od) for a maximum of 30 days.

Official Title
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Rivaroxaban for Treatment of Patients With Suspected or Confirmed Heparin-Induced Thrombocytopenia

Conditions
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Heparin-induced Thrombocytopenia

Intervention / Treatment
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* Drug: Rivaroxaban


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients with 4T's Score greater than or equal to 4. Exclusion Criteria: Require ongoing anticoagulant therapy for a mechanical heart valve. Severe renal insufficiency (CrCl<30 ml/min) Hepatic disease (including Child-Pugh B and C) associated with coagulopathy and a clinically relevant bleeding risk Inability to take oral medications. Ongoing requirement for systemic treatment with azole-antimycotics (except fluconazole) or HIV-protease inhibitors or strong CYP3A4 inducers Clinically significant active bleeding or lesions at increased risk for bleeding within the last 6 months Platelet count less than 80 and an ongoing need for antiplatelet therapy may be excluded at the discretion of the investigator Pregnant or a woman of child-bearing potential not using an adequate birth control method Hypersensitivity to rivaroxaban or to any ingredient in the formulation.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Rivaroxaban<br>Rivaroxaban 15 mg bid until HIT excluded by local laboratory assay or platelets recovered. If HIT positive and platelets have recovered, patients will receive rivaroxaban 20 mg od until Day 30. | Drug: Rivaroxaban<br>* Rivaroxaban 15 mg bid until HIT excluded by local laboratory assay or platelets recovered. If HIT positive and platelets have recovered, patients will receive rivaroxaban 20 mg od until Day 30.<br>* Other names: Xarelto;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of new symptomatic venous and arterial thromboembolism in the study population. |  | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of symptomatic venous and arterial thromboembolism and major bleeding in patients while on-treatment with rivaroxaban. |  | 30 days | 
| Duration of time to platelet recovery in patients with Serotonin Release Assay (SRA) confirmed HIT |  | 30 days | 
| Incidence of venous and arterial thromboembolism in patients with SRA confirmed HIT who receive rivaroxaban. |  | 30 days | 
| Major bleeding in the entire study population and in patients with SRA confirmed HIT who receive rivaroxaban. |  | 30 days | 
| To collect data to prospectively validate a new clinical prediction rule for HIT |  | 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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rivaroxaban, treatment, venous thromboembolism, arterial thromboembolism, thrombocytopenia