A Study of the Safety and Effectiveness of Apixaban in Preventing Blood Clots in Children With Leukemia Who Have a Central Venous Catheter and Are Treated With Asparaginase

Exclusion Criteria

• •Subjects scheduled to have \> 3 Lumbar Punctures over the course of the study treatment period
• •Prior history of documented DVT or PE in the past 3 months
• •Known inherited bleeding disorder or coagulopathy
• •Major surgery \[excluding Central Venous Access Device (CVAD) replacement and bone marrow aspiration and non-open biopsy\] within the last 7 days prior to enrollment that may be associated with a risk of bleeding. Open biopsy is considered a major surgery.
• •Uncontrolled severe hypertension at enrollment. Severe hypertension is defined as a systolic or diastolic blood pressure (BP) \> 5 mm Hg above the 95th percentile as defined by the National High Blood Pressure Education Program Working Group (NHBPEP) established guidelines for the definition of normal and elevated blood pressure in children
• •Extreme hyperleukocytosis, white blood cell (WBC) counts over 200 x 109/L (200,000/microL) at the time of enrollment
• •Liver dysfunction manifested by SGTP (ALT) \> 5X Upper limit of normal (ULN) and/or Aspartate aminotransferase (AST) \>5 X ULN and/or direct (conjugated) bilirubin \> 2X ULN
• •Renal function \< 30% of normal for age and size as determined by the Schwartz formula
• •International normalized ratio (INR) \> 1.4 and activated partial thromboplastin time (aPTT) \> 3 seconds above the upper limit of normal for age, within 1 week prior to enrollment.
• •History of allergy to apixaban or Factor Xa inhibitors
• •History of significant adverse reaction or major bleeding related adverse reaction to other anticoagulant or antiplatelet agents
• •History of any significant drug allergy (such as anaphylaxis or hepatotoxicity
• •Any investigational drug being administered during the study