This study is testing the use of rhIL-11 (recombinant interleukin 11, Neumega) in individuals with Von Willebrand disease. The purpose is to evaluate:

1. if rhIL-11 corrects VWF (Von Willebrand Factor) levels to normal
2. if rhIL-11 and DDAVP together will boost VWF levels even higher
3. the onset, peak, and duration of rhIL-11 effect
4. if rhIL-11 is safe in individuals with Von Willebrand Disease

This is a prospective, single center, open-label, escalating dose Phase II comparison study of interleukin-11 (rhIL-11, Neumega) in subjects with type 1 Von Willebrand Disease (VWD).

The purpose is to establish the clinical safety and hemostatic efficacy of rhIL-11 in individuals with type 1 Von Willebrand disease.

Study subjects will include the following subjects:

1. age >= 18 years of age
2. diagnosis of VWD confirmed by: 2a) at least 2 of 4 abnormal vWD-related coagulation tests; 2b) a past bleeding history

A total of 10-16 subjects are anticipated to be enrolled and complete the study. The specific aims of the study are:

1. to compare the hemostatic efficacy of three escalating doses of rhIL-11
2. to determine the biologic effects of rhIL-11
3. to determine whether DDAVP, when given after the seventh daily dose of rhIL-11, enhances hemostatic efficacy or rhIL-11
4. to compare the safety of three escalating doses of rhIL-11

Efficacy will be based on the number and percent increase of VWD-related coagulation tests into the normal range, or at least to 2-3 times baseline.

Safety will be based on the number and frequency of adverse reactions, including fever, headache, fatigue, arthralgias, myalgias, fluid retention, and edema.

The study will last up to 4 weeks per subject, and for 24 months for the entire study.

Inclusion Criteria:

• Males and females 18 years of age or older
• Confirmed VWD by 2 of 4 VWD coagulation tests abnormal
• A past bleeding history
• No hormone, oral contraceptive, estrogen use in past 8 weeks
• Willingness to have blood drawn
• Willingness to sign informed consent

Exclusion Criteria:

• Presence of other bleeding disorder, e.g. acquired VWD, thrombocytopenia
• Use of estrogens, hormones, oral contraceptives in past 8 weeks
• Use of immunomodulatory or experimental drugs or diuretics
• Pregnant or lactating women
• Past cardiac disease, congestive failure, arrhythmia (e.g. atrial fibrillation, atrial flutter), hypertension, MI, stroke, or thrombosis
• Past allergic reaction to Neumega or DDAVP
• Surgery within the past 8 weeks
• Inability to comply with study protocol requirements
• Concomitant use of antiplatelet drugs, anticoagulants, dextran, aspirin, or NSAIDs
• Treatment with DDAVP, cryoprecipitate, whole blood, plasma, and plasma derivatives containing FVIII, VWF within 5 days of study