EINSTEIN Junior Phase II: Oral Rivaroxaban in Young Children With Venous Thrombosis

30-day, Single-arm Study of the Safety, Efficacy and the Pharmacokinetic and Pharmacodynamic Properties of Oral Rivaroxaban in Young Children With Various Manifestations of Venous Thrombosis

The purpose of this study is to find out whether rivaroxaban is safe to use in children and how long it stays in the body. Safety will be assessed by looking at the incidence and types of bleeding events. There will also be a check for worsening of blood clots.

Inclusion Criteria:

• Children aged 6 months to < 6 years who have been treated for at least 2 months or, in case of catheter related thrombosis, for at least 6 weeks with LMWH (low molecular weight heparin), fondaparinux and/or VKA (vitamin K antagonist) for documented symptomatic or asymptomatic venous thrombosis - Hemoglobin, platelets, creatinine, alanine aminotransferase (ALT) and bilirubin evaluated within 10 days prior to randomization
• Informed consent provided

Exclusion Criteria:

• Active bleeding or high risk for bleeding contraindicating anticoagulant therapy
• Symptomatic progression of venous thrombosis during preceding anticoagulant treatment
• Planned invasive procedures, including lumbar puncture and removal of non peripherally placed central lines during study treatment
• An estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m^2
• Hepatic disease which is associated with either: coagulopathy leading to a clinically relevant bleeding risk, or ALT> 5x upper level of normal (ULN) or total bilirubin > 2x ULN with direct bilirubin > 20% of the total
• Platelet count < 50 x 10*9/L
• Hypertension defined as > 95th age percentile
• Life expectancy < 3 months
• Concomitant use of strong inhibitors of both cytochrome P450 isoenzyme 3A4 (CYP3A4) and P-glycoprotein (P-gp), i.e. all human immunodeficiency virus protease inhibitors and the following azole antimycotics agents: ketoconazole, itraconazole, voriconazole, posaconazole, if used systemically
• Concomitant use of strong inducers of CYP3A4, i.e. rifampicin, rifabutin, phenobarbital, phenytoin and carbamazepine
• Hypersensitivity or any other contraindication listed in the local labeling for the comparator treatment or experimental treatment
• Inability to cooperate with the study procedures
• Previous randomization to this study
• Participation in a study with an investigational drug or medical device within 30 days prior to randomization