Study will assess PK/PD parameters and safety and tolerability of the study medication in this age group

Inclusion criteria:

1. males or females 1 to less than 2 years of age
2. objective diagnosis of primary venous thromboembolism
3. completion of planned treatment course with low molecular weight heparin or oral anticoagulant for primary venous thromboembolism
4. written informed consent by parent (legal guardian) and patient assent (if applicable)

Exclusion criteria:

1. weight less than 9 kg
2. conditions associated with increased risk of bleeding
3. patients who have any condition that would not allow safe participation in study Note: Further exclusion criteria apply