Inclusion Criteria:

1. Have given written informed consent.
2. Be aged 12 years or older.
3. Have severe VWD (VWF:RCo <20%) of known type. Severity will be confirmed by a current VWF:RCo result of <20%.
4. Be known or expected to require a concentrate for management of VWD.
5. Must have had at least one bleed in the last 12 months which required treatment with a FVIII and VWF concentrate.
6. Have a known lack of, or poor response to, DDAVP.
7. Have a prothrombin time (PT) of not more than 3 seconds above the upper limit of the reference range.
8. At the Baseline Visit (Visit 1), patients must have had at least 5 days since their last infusion of replacement factor concentrate or DDAVP.
9. Female patients of child-bearing potential must have a negative result on a human chorionic gonadotropin-based pregnancy test. If a female patient is or becomes sexually active, she must practice contraception by using a method of proven reliability for the duration of the study. Female patients must not be lactating.

Exclusion Criteria:

1. Have a history of inhibitor development to VWF or FVIII or a positive result at screening.
2. Actively bleeding (Note: the patient can enter the study once the bleed is controlled).
3. Presence of major systemic illnesses: renal disease, liver disease, or neurological or psychiatric disease which would compromise the outcome of the study in the opinion of the investigator.
4. Known or suspected hypersensitivity to investigational medicinal product (IMP) or its excipients.
5. Have a recent history of alcohol or drug abuse.
6. Administration of a new chemical entity within the 4 months preceding enrolment.
7. Participation in any other clinical study in which investigational or marketed drugs were employed in the 30 days preceding enrolment into this study, with the exception of the BPL clinical study Protocol 8VWF03.
8. In the opinion of the investigator, the patient is unlikely to comply with the study protocol.