Hematopoietic Stem Cell Transplantation Gene Therapy for Treatment of Severe Hemophilia A

Inclusion Criteria: * Able to provide informed consent for the protocol approved by the Institutional Review Board. * Male subjects who are ≥18 years of age and \< 45 years of age. * Diagnosis of severe hemophilia A (\<1 IU/dl factor VIII activity). * Documented history of more than 100 exposures of factor VIII treatment. * Average of at least 3 bleeds requiring treatment per year over the prior three years, at least 3 bleeds per year during the 3 years preceding the initiation of prophylaxis, or evidence of joint damage (knee, elbow or ankle) on physical or radiographic examination thought to be related to hemophilia. * Performance status (Karnofsky score) of at least 70. * Willing and able to comply with the requirements of the protocol. Exclusion Criteria: * History of spontaneous central nervous system bleeding within the last 5 years. * Significant organ dysfunction which could interfere with outcome of therapy such as: - * Cardiac: There should be no evidence of significant cardiac dysfunction (resting left ventricular ejection fraction of \< 50%) and no cardiomegaly. There should not be uncontrollable hypertension. * Renal: Glomerular Filtration Rate (GFR) \< 60 ml/min/1.73m2 as calculated using the Cockcroft-Gault equation. * Hepatic: There should be no evidence of hepatic dysfunction which is defined as a serum bilirubin of \> 1.5 mg/dl and Aspartate Amino Transferase (AST) / Alanine Amino Transferase (ALT) \> 3X the upper limit of normal, * Hematologic: Absolute neutrophil counts (ANC) \< 1000/mm3 and platelets counts \< 150,000/μL. * Pulmonary function with a corrected Diffusing Capacity of lung for Carbon Monoxide (DLCO) of \< 50% predicted * History of a FVIII inhibitor (\>0.6 Bethesda Units/ml) including at least 2 measurements over the preceding 5 years or any single titer \>5 Bethesda Units (BU) /ml. * Previous stem cell transplant. * HIV positive. * Evidence of hepatitis B active infection or chronic carrier * Evidence of chronic hepatitis C infection. Absence of chronic infection will be documented with at least 2 negative viral loads at least 6 months apart. * Diagnosis of a bleeding disorder other than hemophilia A * Use of medication(s) that can affect hemostasis (e.g. aspirin and non- cyclooxygenase (COX-2) selective non-steroid anti-inflammatory drugs). * History of cancer or familial cancer syndromes * Any condition in the opinion of the principle investigator that will negatively impact the subject's ability to safely undergo an autologous stem cell transplant. * Any reason in the opinion of the principle investigator that will negatively impact the subject's ability to complete the clinical trial per the trial protocol.