Recruiting

Anticoagulation Strategies

Sponsor:

Tzu-Fei Wang

Code:

NCT05255003

Conditions

Cancer-associated Thrombosis

Thrombocytopenia

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Enoxaparin

Dalteparin

Tinzaparin

Study Details

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 2 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 30 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 for these patients.

Conditions

Cancer-associated Thrombosis

Thrombocytopenia

Study ID

NCT05255003

Start date

Aug 29, 2022

Status verified date

Dec, 2025

Completion date

Jan 31, 2027

Anticipated

Primary completion date

Dec, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Adult patients (age ≥ 18) with active malignancy (malignancy diagnosed or treated within the previous 6 months, or progressive/relapsed);
2. Objectively confirmed VTE within last 14 days for which therapeutic anticoagulation is planned;
3. Thrombocytopenia with a platelet count < 50,000/uL from cancer therapy or malignancy itself;
4. Able to provide written informed consent

Exclusion Criteria:

1. Receipt of anticoagulant for index VTE with platelet count < 50,000/uL for > 72 hours;
2. Superficial vein thrombosis only;
3. Life expectancy < 1 month (as judged by the treating physicians);
4. Creatinine clearance < 30 ml/min;
5. Contraindication to LMWH such as a history of heparin induced thrombocytopenia;
6. Thrombocytopenia from other causes, such as thrombotic microangiopathy, immune thrombocytopenia, disseminated intravascular coagulation;
7. Previously documented history of refractoriness to platelet transfusion secondary to HLA antibodies;
8. Refusal of blood products;
9. Anticoagulation at any dose is deemed unsafe (i.e. active bleeding or bleeding disorders)

Study Design

Enrollment

50 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Modified dose LMWH without platelet transfusion support

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

active comparator: Higher dose LMWH with platelet transfusion support

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

Interventions

Enoxaparin

I. Platelet count 25-50,000/µL: 0.5mg/kg subcutaneously twice daily

II. Platelet count < 25,000/µL: hold anticoagulation

Dalteparin

I. Platelet count 25-50,000/µL: 100 IU/kg subcutaneously daily for the first month of an acute VTE then 75 U/kg

II. Platelet count < 25,000/µL: hold anticoagulation

Tinzaparin

I. Platelet count 25-50,000/µL: 87.5 units/kg subcutaneously daily

II. Platelet count < 25,000/µL: hold anticoagulation

Primary outcome measure

  • Feasibility - The average number of patients recruited per month [ Time Frame: 18 months ]

Central Contacts and Locations

Central contacts

Jennifer Brinkhurst

+16137378899jbrinkhurst@ohri.ca

Locations

The Ottawa Hospital

Recruiting

Ottawa, Ontario, Canada, K1H 8L6

Contacts

Jennifer Multicentre Trial Coordinator

6137378899jbrinkhurst@ohri.ca

Principal Investigator:

Tzu-Fei Wang, MD

Niagara Health - St. Catharines Site

Recruiting

Saint Catharines, Ontario, Canada

Principal Investigator:

Blair Leonard

Windsor Regional Hospital

Recruiting

Windsor, Ontario, Canada, N8W 1L9

More Information

Sponsor

Tzu-Fei Wang

Last update posted

Dec 17, 2025

Last verified

Dec, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Tzu-Fei Wang on 2025-12-17.