The aim of this study is to assess the pharmacokinetics (PK), efficacy, and safety of Biostate® in subjects with Von Willebrand Disease (VWD).

Pharmacokinetic Component:

PK parameters will be determined from a subgroup of subjects. Subjects who complete the PK component will subsequently continue in the efficacy component of the study, either continuing on a previously established prophylaxis regimen or continuing to receive on-demand treatment with the occurrence of non-surgical bleeding (NSB) events.

Efficacy Component:

Three treatment arms are defined for the efficacy component of the study. (1) Subjects who are currently being treated on a set prophylaxis regimen with a VWF product at the time of study entry will be enrolled in the "Prophylaxis" arm. (2) Subjects not being treated on a set prophylaxis regimen at the time of study entry who require a VWF product for the treatment of NSB events will be enrolled in the "On-demand" arm and commence using Biostate in the treatment of NSB events. (3) Subjects enrolled in the "On-demand" arm have the possibility to enter the "Cross-over to Prophylaxis" arm to receive an additional 12 months of prophylactic treatment.

Inclusion Criteria:

• Diagnosed with VWD
• Desmopressin acetate (DDAVP) treatment is ineffective or contraindicated or not available
• Evidence of vaccination against hepatitis A and B (or presence of antibodies against hepatitis A and B) within 10 years prior to their first dose of Biostate®
• Written informed consent given

Exclusion Criteria (for participation in the PK component):

• Actively bleeding immediately prior to initial PK period
• Have received DDAVP or a VWF product in the 5 days prior to their first dose of study product
• Have Type 2B, 2N or 2M VWD

Exclusion Criteria (for all subjects):

• Requiring a VWF product for a planned surgical procedure at enrolment
• Have received aspirin or other non-steroidal anti-inflammatory drugs within 7 days prior to their first dose of study product
• Known history of, or are suspected to have, VWF or FVIII inhibitors
• Suffering an acute or chronic medical condition, other than VWD, which may affect the conduct of the study
• Known or suspected hypersensitivity or previous evidence of severe side effects to Biostate®, VWF/FVIII concentrates, or human albumin
• Impaired liver function at screening
• Evidence or a history (within the previous 12 months) of abuse of any drug substance, licit or illicit
• Participation in a clinical study or use of an investigational compound in the 3 months preceding the first day of study drug administration, or plans to enter such a study during the study period.
• Females who are pregnant, breast-feeding or who have a positive pregnancy test at screening