STrategies for Anticoagulation in Patients With thRombocytopenia and Cancer-associated Thrombosis
- Conditions
- ThrombocytopeniaCancer-associated Thrombosis
- Interventions
- Biological: EnoxaparinBiological: DalteparinBiological: Tinzaparin
- Registration Number
- NCT05255003
- Lead Sponsor
- Ottawa Hospital Research Institute
- Brief Summary
Patients with cancer are prone to have blood clots, which are usually treated with blood thinners. The main complication of blood thinners is bleeding. This is especially a concern when the number of platelets in the blood is lower than 50,000 per microliter. The role of platelets is to stop bleeding, so when the number of platelets is low, patients are at a higher risk of bleeding. Cancer patients are prone to have lower platelet numbers due to cancer therapies and/or cancer itself. It is not clear what the best treatment is for cancer patients who need blood thinners for a blood clot but have low platelet counts.
The investigators plan to do a small study called a pilot study to help plan for a larger study in such patients. In the pilot study, investigators will include 50 patients with cancer, low platelet counts, and a blood clot diagnosed within 4 weeks. Patients will be randomly assigned to one of the two treatment strategies: the full dose of blood thinners along with platelet transfusion or a reduced dose of blood thinners without platelet transfusion. The investigators will follow all patients for 90 days. If this pilot study is successful, it will help lead to a much larger trial, which will provide important information on the best treatment strategy in these patients.
- Detailed Description
The current proposal is for the pilot trial to assess feasibility of a full-scale RCT. To determine feasibility, the pilot and the full-scale trials will use the same recruitment strategy, inclusion/exclusion criteria, interventions, follow up duration, and measurement/adjudication of clinical outcomes. If the pilot trial finds that the full-scale trial is feasible, and no changes to the study design are indicated, the data from the pilot trial will be included in the full-scale trial, which will be efficient and reduce the recruitment time and costs of the full-scale trial.
The START trial is a multi-centre RCT with prospective, open-label, blind-evaluator (PROBE) design. Adult patients with acute cancer-associated thrombosis (diagnosed within 14 days) and thrombocytopenia (platelet count \< 50,000/µL) secondary to cancer therapy or cancer itself will be randomized 1:1 to modified dose LMWH or higher dose LMWH with platelet transfusion support, to evaluate the superiority of a modified dose LMWH strategy in reducing clinically relevant bleeding events compared to full dose LMWH with platelet transfusion. The PROBE design is an efficient use of research funds while maintaining the benefits of randomization and blinded evaluation of endpoints.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 50
- Adult patients (age ≥ 18) with active malignancy (malignancy diagnosed or treated within the previous 6 months, or progressive/relapsed);
- Objectively confirmed VTE within last 14 days for which therapeutic anticoagulation is planned;
- Thrombocytopenia with a platelet count < 50,000/uL from cancer therapy or malignancy itself;
- Able to provide written informed consent
- Receipt of anticoagulant for index VTE with platelet count < 50,000/uL for > 72 hours;
- Superficial vein thrombosis only;
- Life expectancy < 1 month (as judged by the treating physicians);
- Creatinine clearance < 30 ml/min;
- Contraindication to LMWH such as a history of heparin induced thrombocytopenia;
- Thrombocytopenia from other causes, such as thrombotic microangiopathy, immune thrombocytopenia, disseminated intravascular coagulation;
- Previously documented history of refractoriness to platelet transfusion secondary to HLA antibodies;
- Refusal of blood products;
- Anticoagulation at any dose is deemed unsafe (i.e. active bleeding or bleeding disorders)
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Modified dose LMWH without platelet transfusion support Dalteparin Patients will be given modified dose LMWH as below based on the first platelet count of the day (daily in admitted patients or at least 2 times a week in outpatients), without empiric platelet transfusion: I. Platelet count 25-50,000/µL: 50% dose LMWH II. Platelet count \< 25,000/µL: hold anticoagulation Higher dose LMWH with platelet transfusion support Dalteparin Patients assigned to higher dose LMWH (see below) will be given transfusion for 14 days when the first platelet count of the day falls below 50,000/uL (daily inpatient or at least 2 times a week in outpatients). Post-transfusion counts will not be routinely obtained unless clinically indicated I. Platelet count 25-50,000/µL: platelet transfusion + 100% dose LMWH II. Platelet count \< 25,000/µL: platelet transfusion + 50% dose LMWH After Day 14, patients will be transitioned to modified dose LMWH as the other arm without platelet transfusion. LMWH can include enoxaparin, dalteparin, or tinzaparin, with 100% as: * Enoxaparin - 1mg/kg subcutaneously twice daily * Dalteparin - 200 IU/kg subcutaneously daily for 1 month then 150 U/kg daily * Tinzaparin - 175 units/kg subcutaneously daily Modified dose LMWH without platelet transfusion support Enoxaparin Patients will be given modified dose LMWH as below based on the first platelet count of the day (daily in admitted patients or at least 2 times a week in outpatients), without empiric platelet transfusion: I. Platelet count 25-50,000/µL: 50% dose LMWH II. Platelet count \< 25,000/µL: hold anticoagulation Modified dose LMWH without platelet transfusion support Tinzaparin Patients will be given modified dose LMWH as below based on the first platelet count of the day (daily in admitted patients or at least 2 times a week in outpatients), without empiric platelet transfusion: I. Platelet count 25-50,000/µL: 50% dose LMWH II. Platelet count \< 25,000/µL: hold anticoagulation Higher dose LMWH with platelet transfusion support Enoxaparin Patients assigned to higher dose LMWH (see below) will be given transfusion for 14 days when the first platelet count of the day falls below 50,000/uL (daily inpatient or at least 2 times a week in outpatients). Post-transfusion counts will not be routinely obtained unless clinically indicated I. Platelet count 25-50,000/µL: platelet transfusion + 100% dose LMWH II. Platelet count \< 25,000/µL: platelet transfusion + 50% dose LMWH After Day 14, patients will be transitioned to modified dose LMWH as the other arm without platelet transfusion. LMWH can include enoxaparin, dalteparin, or tinzaparin, with 100% as: * Enoxaparin - 1mg/kg subcutaneously twice daily * Dalteparin - 200 IU/kg subcutaneously daily for 1 month then 150 U/kg daily * Tinzaparin - 175 units/kg subcutaneously daily Higher dose LMWH with platelet transfusion support Tinzaparin Patients assigned to higher dose LMWH (see below) will be given transfusion for 14 days when the first platelet count of the day falls below 50,000/uL (daily inpatient or at least 2 times a week in outpatients). Post-transfusion counts will not be routinely obtained unless clinically indicated I. Platelet count 25-50,000/µL: platelet transfusion + 100% dose LMWH II. Platelet count \< 25,000/µL: platelet transfusion + 50% dose LMWH After Day 14, patients will be transitioned to modified dose LMWH as the other arm without platelet transfusion. LMWH can include enoxaparin, dalteparin, or tinzaparin, with 100% as: * Enoxaparin - 1mg/kg subcutaneously twice daily * Dalteparin - 200 IU/kg subcutaneously daily for 1 month then 150 U/kg daily * Tinzaparin - 175 units/kg subcutaneously daily
- Primary Outcome Measures
Name Time Method Feasibility - The average number of patients recruited per month 18 months The average number of patients recruited per month
- Secondary Outcome Measures
Name Time Method Feasibility - Rates of withdrawal 18 months Number of participants withdrawing from study
Feasibility - Reasons for non-participation in eligible patients 18 months Reasons for non-participation in eligible patients
Feasibility - Number of patients who complete study procedures by adhering to protocol 18 months Number of participants adhering to the protocol (such as anticoagulation, transfusion, platelet count monitoring according to the protocol)
Feasibility - Proportion of eligible patients who provide consent 18 months Number of consenting participants from the number of eligible patients
Clinical Outcome - Rate of symptomatic or incidentally detected recurrent or new major VTE 18 months Rate of symptomatic or incidentally detected recurrent or new major VTE
Clinical Outcome - PE-related death 18 months PE-related death
Clinical Outcome - Composite of recurrent VTE and major bleeding events 18 months Composite of recurrent VTE and major bleeding events
Feasibility - Loss to follow-up 18 months Number of participants lost to follow-up
Clinical Outcome - Rate of clinically relevant bleeding (composite of major bleeding and clinically relevant non-major bleeding events) 18 months Rate of clinically relevant bleeding (composite of major bleeding and clinically relevant non-major bleeding events)
Clinical Outcome - Non-major VTE (distal upper or lower extremity DVT, superficial upper or lower extremity vein thrombosis) 18 months Number of non-major VTE (distal upper or lower extremity DVT, superficial upper or lower extremity vein thrombosis)
Clinical Outcome - Duration of thrombocytopenia (days of platelet count < 50,000/uL) per patient 18 months Duration of thrombocytopenia (days of platelet count \< 50,000/uL) per patient
Clinical Outcome - Number of transfused units and adverse platelet transfusion reactions 18 months Number of transfused units and adverse platelet transfusion reactions
Clinical Outcome - Overall mortality 18 months Overall mortality
Feasibility - Crossover between treatment arms 18 months Number of participants crossing over between treatment arms
Clinical Outcome - Health-related quality of life using EuroQoL-EQ-5D-5L questionnaire 18 months Health-related quality of life using EuroQoL-EQ-5D-5L questionnaire
Trial Locations
- Locations (3)
The Ottawa Hospital
🇨🇦Ottawa, Ontario, Canada
Windsor Regional Hospital
🇨🇦Windsor, Ontario, Canada
University of Alberta
🇨🇦Edmonton, Alberta, Canada