Apixaban for the Acute Treatment of Venous Thromboembolism in Children

• Drug: Apixaban
  
  Tablet or Solution
• Drug: Standard of Care
  
  Unfractionated heparin, low molecular weight heparin, and/or a vitamin K antagonist. For subjects under 2 years of age, standard of care will be limited to unfractionated heparin or low molecular weight heparin.

• Experimental: Apixaban
  
  Subjects between 28 days to <18 years will be dosed on a body weight tiered regimen. Subjects > or = 35 kg will receive 10 mg twice daily for 7 days followed by 5 mg twice daily thereafter;<35 kg to 25 kg will receive 8 mg twice daily for 7 days followed by 4 mg twice daily thereafter; <25 to 18 kg will receive 6 mg twice daily for 7 days and then 3mg twice daily thereafter; <18 to 12 kg will receive 4 mg twice daily for 7 days and then 2 mg twice daily thereafter; <12 to 9 kg will receive 3 mg twice daily for 7 days and then 1.5 mg twice daily thereafter; <9 kg to 6 kg will receive 2 mg twice daily for 7 days and 1 mg twice daily thereafter; <6 kg to 5 kg will receive 1 mg twice daily for 7 days and 0.5 mg twice daily thereafter; <5 kg to 4 kg will receive 0.6 mg twice daily for 7 days and 0.3 mg twice daily thereafter.
  Intervention: Drug: Apixaban
• Active Comparator: Standard of Care
  
  Subjects will receive a dose and dosing regimen of anticoagulation treatment based on usual and customary care per local practices.
  Intervention: Drug: Standard of Care

Inclusion Criteria:

1. 28 days to <18 years of age with a minimum weight of 4 kg at the time of randomization.
2. Presence of an index VTE which is confirmed by imaging.
3. Intention to manage the index VTE with anticoagulation treatment for at least 6 to 12 weeks.
4. Subjects able to tolerate oral feeding, nasogastric (NG), gastric (G) feeding for at least 5 days.

Exclusion Criteria:

1. Anticoagulant treatment for the index VTE for greater than 14 days prior to randomization.
2. Thrombectomy, thrombolytic therapy, or insertion of a caval filter to treat the index VTE.
3. A mechanical heart valve.
4. Active bleeding or high risk of bleeding at the time of randomization.
5. Intracranial bleed, including intraventricular hemorrhage, within 3 months prior to randomization.
6. Abnormal baseline liver function at randomization.
7. Inadequate renal function at the time of randomization.
8. Platelet count <50×109 per L at randomization.
9. Uncontrolled severe hypertension at the time of randomization.
10. Use of prohibited concomitant medication at the time of randomization.
11. Female subjects who are either pregnant or breastfeeding a child.
12. Use of aggressive life-saving therapies such as ventricular assist devices (VAD) or extracorporeal membrane oxygenation (ECMO) at the time of enrollment.
13. Unable to take oral or enteric medication via the NG or G tube.
14. Known inherited or acquired antiphospholipid syndrome (APS).
15. Known inherited bleeding disorder or coagulopathy with increased bleeding risk (eg, hemophilia, von Willebrand disease, etc.)