• objectively-proven symptomatic VTE (DVT or PE)
  

• bleeding (major and all bleeding)
  
• quality of life
  
• cognition assessments
  
• death
  

Patients are randomized 1:1 to receive dalteparin 5,000 anti-Xa units s.c. daily versus placebo s.c. daily. The primary outcome is VTE-free survival at 6 months. Progression free survival; overall survival, toxicity, and neurocognitive performance are secondary outcome measures.

Inclusion Criteria:

• Both of the following criteria must be satisfied:

  1. Patients with newly-diagnosed pathologically-confirmed WHO Grade 3 or Grade 4 glioma (anaplastic astrocytoma, glioblastoma multiforme, gliosarcoma, anaplastic oligodendroglioma, and anaplastic mixed glioma). Tumour histology is based on local pathology review only;
  2. Patients 18 years of age or older at time of randomization

Exclusion Criteria:

• If one or more of the following criteria are satisfied, the patient is not eligible for the study:

  1. The presence of acute or chronic DVT demonstrated by duplex ultrasonography (DUS) or venography. (Note: a screening DUS is not required for study entry);
  2. Inability to commence study drug within four weeks of original surgery or biopsy;
  3. Serious hemorrhage requiring hospitalization, transfusion, or surgical intervention within four weeks of potential study entry;
  4. Presence of a coagulopathy (e.g. INR >1.5 or platelet count < 100x109/L);
  5. Symptomatic intracranial or intratumoural bleeding. (Note: post-operative imaging of the brain is not required for study entry. Asymptomatic “routine” post-operative blood products in a post-surgical cavity are not an exclusion;
  6. Known acute (symptomatic or actively bleeding) gastroduodenal ulcer;
  7. Familial bleeding diathesis;
  8. Requiring long term anticoagulants for other reasons (e.g., mechanical heart valves, atrial fibrillation);
  9. Uncontrolled hypertension despite antihypertensive therapy;
  10. Significant renal failure (dependent on dialysis or creatinine of greater than three times upper limit of normal control);
  11. Prior history of documented DVT or PE;
  12. Allergy to anticoagulants (UFH, LMWH) including immune-mediated heparin-induced thrombocytopenia;
  13. Pregnant or of childbearing potential and not using adequate contraception;
  14. Geographically inaccessible for follow-up;
  15. Having an expected life span of less than 6 months;
  16. Body weight < 40 kg.