Efficacy and Safety of IL-11 in DDAVP Unresponsive

Inclusion Criteria: * Males or females \>= 18 years of age. * A diagnosis of hemophilia A, moderate (FVIII:C 0.01-0.04 U/ml) or mild (FVIII:C \>= 0.05 U/ml); or a diagnosis of VWD, defined by a low VWF:RCo and past bleeding history. * For those with VWD, an inability to use DDAVP due to i) unresponsiveness defined as VWF:RCo or FVIII:C level lower than 50 IU/dl or less than a 3-fold increase after 0.3 microgram/kg DDAVP; ii) allergic reactions or seizures; or iii) a contraindication to DDAVP. * Willingness to have blood drawn. * Willingness to sign informed consent. Exclusion Criteria: * Presence of other bleeding disorders, acquired Von Willebrand disease, primary thrombocytopenia. * Use of immunomodulatory or experimental drugs, or diuretics. * Pregnant or lactating women. * Previous cardiac disease, congestive failure, arrhythmia (e.g. atrial fibrillation, atrial flutter), hypertension, MI, stroke, or thrombosis. * Past allergic reaction to Neumega. * 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 substantial quantities of FVIII and/or VWF within five days of study. * Baseline safety and/or hematology lab values outside the normal limits and/or an EKG indicating an arrhythmia.