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Cancer-associated ThrombosisPhase 4NCT05255003

STrategies for Anticoagulation in Patients With thRombocytopenia and Cancer-associated Thrombosis

A Phase 4 study testing Enoxaparin, Dalteparin and Tinzaparin in people with Cancer-associated Thrombosis and Thrombocytopenia, run by Tzu-Fei Wang at 4 sites in Canada.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
Enoxaparin, Dalteparin and Tinzaparin
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
50 participants
Where
4 sitesCanada
Study dates
29 Aug 2022to 31 Jan 2027
Phase
Phase 4
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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

Who cannot join

  • 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;
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  • 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)

Trial locations and contacts

4 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Jennifer Brinkhurst contact

+16137378899 ext. 71068

jbrinkhurst@ohri.ca

Canada4 sites, 3 recruiting

  • University of Alberta

    Edmonton, Alberta

    Withdrawn

  • The Ottawa Hospital

    Ottawa, Ontario, K1H 8L6

    Jennifer Multicentre Trial Coordinator, 6137378899 ext. 71068, jbrinkhurst@ohri.ca

    Tzu-Fei Wang, MD

    Recruiting

  • Niagara Health - St. Catharines Site

    Saint Catharines, Ontario

    Blair Leonard

    Recruiting

  • Windsor Regional Hospital

    Windsor, Ontario, N8W 1L9

    Andrea Cervi, MD

    Recruiting

Other trials in Canada

About this study

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.

Read the 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.

Being tested
Enoxaparin, Dalteparin, Tinzaparin
Medical subject headings
Thrombocytopenia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • EnoxaparinBiological

    Also called Lovenox

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

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

  • DalteparinBiological

    Also called Fragmin

    1. 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

  • TinzaparinBiological

    Also called Innohep

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

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

Study groups in NCT05255003
Study groupRoleWhat they receive
Modified dose LMWH without platelet transfusion supportExperimentalPatients 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
Receives: Biological: Enoxaparin; Biological: Dalteparin; Biological: Tinzaparin
Higher dose LMWH with platelet transfusion supportActive comparatorPatients 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
Receives: Biological: Enoxaparin; Biological: Dalteparin; Biological: Tinzaparin

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Feasibility - The average number of patients recruited per month

    The average number of patients recruited per month

    Measured: 18 months

Secondary outcomes (15)

  1. Feasibility - Proportion of eligible patients who provide consent

    Number of consenting participants from the number of eligible patients

    Measured: 18 months

  2. Feasibility - Reasons for non-participation in eligible patients

    Reasons for non-participation in eligible patients

    Measured: 18 months

  3. Feasibility - Number of patients who complete study procedures by adhering to protocol

    Number of participants adhering to the protocol (such as anticoagulation, transfusion, platelet count monitoring according to the protocol)

    Measured: 18 months

  4. Feasibility - Rates of withdrawal

    Number of participants withdrawing from study

    Measured: 18 months

  5. Feasibility - Loss to follow-up

    Number of participants lost to follow-up

    Measured: 18 months

  6. Feasibility - Crossover between treatment arms

    Number of participants crossing over between treatment arms

    Measured: 18 months

  7. Clinical Outcome - Rate of clinically relevant bleeding (composite of major bleeding and clinically relevant non-major bleeding events)

    Rate of clinically relevant bleeding (composite of major bleeding and clinically relevant non-major bleeding events)

    Measured: 18 months

  8. Clinical Outcome - Rate of symptomatic or incidentally detected recurrent or new major VTE

    Rate of symptomatic or incidentally detected recurrent or new major VTE

    Measured: 18 months

  9. Clinical Outcome - PE-related death

    PE-related death

    Measured: 18 months

  10. Clinical Outcome - Composite of recurrent VTE and major bleeding events

    Composite of recurrent VTE and major bleeding events

    Measured: 18 months

  11. Clinical Outcome - Non-major VTE (distal upper or lower extremity DVT, superficial upper or lower extremity vein thrombosis)

    Number of non-major VTE (distal upper or lower extremity DVT, superficial upper or lower extremity vein thrombosis)

    Measured: 18 months

  12. Clinical Outcome - Duration of thrombocytopenia (days of platelet count < 50,000/uL) per patient

    Duration of thrombocytopenia (days of platelet count < 50,000/uL) per patient

    Measured: 18 months

  13. Clinical Outcome - Number of transfused units and adverse platelet transfusion reactions

    Number of transfused units and adverse platelet transfusion reactions

    Measured: 18 months

  14. Clinical Outcome - Overall mortality

    Overall mortality

    Measured: 18 months

  15. Clinical Outcome - Health-related quality of life using EuroQoL-EQ-5D-5L questionnaire

    Health-related quality of life using EuroQoL-EQ-5D-5L questionnaire

    Measured: 18 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Feb 2022
  2. Study start29 Aug 2022
  3. Primary completionDec 2026 (estimated)
  4. Study completion31 Jan 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05255003
Sponsor's protocol ID
START Pilot
Status last verified
Dec 2025
First submitted
6 Feb 2022
Last updated
17 Dec 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Enoxaparin, Dalteparin and Tinzaparin in people with Cancer-associated Thrombosis and Thrombocytopenia, run by Tzu-Fei Wang at 4 sites in Canada.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 17 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Jennifer Brinkhurst (+16137378899 ext. 71068, jbrinkhurst@ohri.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Feasibility - The average number of patients recruited per month (time frame: 18 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05255003.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Dec 2025.

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