Safety Study of Zileuton Injection in Patients With Asthma

Inclusion Criteria: * Diagnosis of asthma * Morning FEV1 of 40-80% of predicted normal * Evidence post-bronchodilator increase in FEV1 of at least 15% * Evidence of at least 10% increase in FEV1 within 3 hours after oral 600 mg zileuton dose * Signed IRB approved informed consent * Patients must be willing and able to withhold: * short acting β2-agonists for at least 6 hours prior to spirometry * inhaled corticosteroids (ICS) for at least 24 hours prior to sprirometry * long acting β2-agonists (LABA) for 7 days and be willing and able to switch from a LABA/ICS combination product to a monotherapy ICS product Exclusion Criteria: * Females of childbearing potential not using effective contracception * Any uncontrolled systemic disease other than asthma * Patient with known hypersensitivity to zileuton IR tablets or zileuton injection or any of the components found therein * An upper or lower respiratory tract infection within 2 weeks of screening * An ED visit or hospitalization for asthma within 3 months of screening * Oral or parenteral corticosteroid use for asthma exacerbation within 3 months of screening * Current cigarette smoker and/or \>10 pack-year smoking history * History of hepatitis B (HBV) or hepatitis C infection or other active liver disease or chronic hepatitis * Screening ALT \>1.5x ULN * Patient with impaired renal function or serum creatinine \>1.5x ULN * History of HIV infection * History of drug or alcohol abuse within 1 year of screening * Patient taking any of the following asthma/allergy medications: * Anti-IgE meds within 3 months of screening * Zileuton IR tablets within 1 month of screening * Inhaled or oral steroids not stable for at least 1 month * Theophylline, cromolyn, or nedocromil within 7 days of screening * Leukotriene receptor agonists within 7 days of screening * Warfarin, propranolol, inhaled or sytemic anticholinergics within 7 days of screening * Long acting beta agonist within 7 days of screening * Oral beta-2 agonists within 12 hours of screening * Immunotherapy injections not in a stable dosing phase * Female patient who is pregnant or breast-feeding or plans to become pregnant during the study period * Participation in another research study within 30 days of screening * Patient is the Investigator or other staff or relative who is directly involved in the conduct of the study