Inclusion Criteria:  Patients aged <6 years at the time of screening Type 3 (at least four patients), severe type 2 (except 2N) or severe type 1 VWD (VWF:RCo <20%) according to medical history, requiring substitution therapy with a VWF-containing product Minimum body weight 12.5 kg at the time of screening Voluntarily given, fully informed written and signed consent obtained before any study-related procedures are conducted (obtained from the patient's parent(s)/ legal guardian(s))  Exclusion Criteria:  History or current suspicion of VWF or FVIII inhibitors Injection of DDAVP or VWF-containing product within 72 hours prior to inclusion Medical history of a thromboembolic event Platelet count <100,000/µL at screening (except for VWD type 2B) Patients receiving, or scheduled to receive, immunosuppressant drugs (other than antiretroviral chemotherapy), such as prednisone (equivalent to >10 mg/day), or similar drugs Treatment with any investigational medicinal product (IMP) in another interventional clinical study currently or within four weeks before enrolment Other coagulation disorders or bleeding disorders Known hypersensitivity to any of the components of the study drug