TREATT: This phase III trial is trying to determine whether it is effective to give tranexamic acid (a drug that reduces heavy bleeding) to patients with ThrombocytopeniaA double blind, randomised controlled TRial EvaluAting the safety and efficacy of Tranexamic acid in patients with haematological malignancies with severe Thrombocytopenia

Exclusion

A patient will not be eligible for this trial if he/she fulfils one or more of the following criteria:

1. Patients with a past history or current diagnosis of arterial or venous thromboembolic disease including myocardial infarction, peripheral vascular disease and retinal arterial or venous thrombosis.
2. Diagnosis of acute promyelocytic leukaemia (APML) and undergoing induction chemotherapy
3. Patients with a diagnosis/previous history of veno-occlusive disease (also called sinusoidal obstruction syndrome)

4. Patients with known inherited or acquired prothrombotic disorders e.g.

   1. Lupus anticoagulant
   2. Positive antiphospholipids
5. Patients receiving any pro-coagulant agents (e.g. DDAVP, recombinant Factor VIIa or Prothrombin Complex Concentrates (PCC) within 48 hours of enrolment, or with known hypercoagulable state
6. Patients receiving L-asparaginase as part of their current cycle of treatment
7. History of immune thrombocytopenia (ITP), thrombotic thrombocytopenic purpura (TTP) or haemolytic uraemic syndrome (HUS)
8. Patients with overt disseminated intravascular coagulation (DIC) (See Appendix 3 in the protocol for definition)
9. Patients requiring a platelet transfusion threshold >10x10/⁹L at time of randomisation. (This refers to patients who require their platelet count to be maintained at a certain specified level on an ongoing basis, and excludes a transient rise in the threshold due to sepsis.)

10. Patients with a known inherited or acquired bleeding disorder e.g.

    1. Acquired storage pool deficiency
    2. Paraproteinaemia with platelet inhibition
11. Patients receiving anticoagulant therapy or anti-platelet therapy
12. Patients with visible haematuria at time of randomisation
13. Patients with anuria (defined as urine output < 10 mls/hr over 24 hours).
14. Patients with severe renal impairment (eGFR ≤30 ml/min/1.73m²)
15. Patients with a previous history of epilepsy, convulsions, fits or seizures
16. Patients who are pregnant or breast-feeding
17. Allergic to tranexamic acid.
18. Patients enrolled in other trials involving platelet transfusions, anti-fibrinolytics, platelet growth factors or other pro-coagulant agents.
19. Patients previously randomised into this trial at any stage of their treatment.