This is a Phase II, multicenter, randomized, double blind, placebo controlled, multiple-dose study designed to evaluate the efficacy, safety, and tolerability of subcutaneously administered HAE1 in subjects 12-75 years old with moderate to severe asthma whose symptoms are inadequately controlled with moderate to high-dose ICS and LABA.

Inclusion Criteria:

• Signed Informed Consent Form(s)
• Male and females 12-75 years of age with the diagnosis of allergic asthma for 12 months according to the standards of the American Thoracic Society
• Baseline FEV1 values ≥ 40% to ≤ 80% of the predicted normal value for the subject
• Demonstration of ≥ 12% increase in FEV1 over baseline value within 30 minutes of taking up to four puffs of albuterol (90 ug/puff)
• Treatment with ICS in doses equivalent to 250-500 ug fluticasone twice daily (BID) for 8 weeks prior to screening and as needed or regular use of bronchodilator therapy
• Treatment with a stable regimen of 50 ug salmeterol BID or 12 ug formoterol BID for at least 8 weeks prior to screening (with or without other asthma controller medications)
• A positive radioallergosorbent test (RAST) to one or more of the pertinent perennial or seasonal allergens
• Total serum IgE level ≥ 20 to ≤ 1500 IU/mL and body weight between ≥ 40 and ≤ 150 kg
• Acceptable medical history and physical examination results
• Demonstrated ability to use Mini-Wright peak flow meter for the measurement of peak expiratory flow (PEF) and a metered dose inhaler (MDI) for administration of albuterol rescue medication
• Willingness to complete the daily diary cards
• History of smoking of less than 10 pack-years and no smoking for ≥ 12 months
• For females of childbearing potential, use an effective method of contraception from screening throughout their duration of study participation (e.g., oral, mechanical, SC, or surgical contraception)
• Inadequately controlled asthma 4 weeks during the run-in period as demonstrated by either of the following: One or more nighttime awakenings per week or Asthma symptoms during the day requiring rescue medication for 2 or more days per week

Exclusion Criteria:

• Active lung disease other than asthma
• Asthma exacerbation requiring treatment with the addition of systemic (oral or IV) corticosteroids or an increase in systemic corticosteroids within 1 month prior to screening or during the run-in period
• Significant change (e.g., 50% change) in dosage of inhaled corticosteroids in daily dose or dosing schedule within 1 month of prior to the screening visit or during the run-in period
• Significant medical illness other than asthma
• Treatment with methotrexate, gold salts, cyclosporine, theophyllines, or macrolide antibiotics within 3 months prior to screening or during the run-in period
• Treatment with HAE1
• Any treatment with omalizumab
• Known hypersensitivity to the ingredients of the HAE1 formulation, to trial rescue medication (albuterol), or related drugs
• History of acute infectious sinusitis or respiratory tract infection within 1 month prior to screening or during the run-in period
• Aspirin or other nonsteroidal anti-inflammatory drug-related asthma
• Allergy vaccination therapy < 3 months of stable maintenance dose prior to screening
• Treatment with oral or parenteral corticosteroids within 1 month prior to screening or during the run-in period
• Current treatment with <beta>-blocker medications (e.g., propranolol)
• Clinically significant abnormality on 12-lead electrocardiogram (ECG) at screening
• Abnormal chest X-ray (excluding changes consistent with asthma) within 12 months prior to screening
• Clinically significant or active systemic disease (e.g., cancer, neoplasia, infection, hematological, renal, hepatic, coronary heart disease or other cardiovascular diseases, or endocrine or gastrointestinal disease) within 3 months of screening or during the run-in period
• Inability or unwillingness to comply with study procedures and visits (e.g., spirometry, blood draws, subject diary)
• History of drug or alcohol abuse
• Elevated serum IgE levels for reasons other than allergy (e.g., parasitic infection, hyperimmunoglobulin E syndrome, Wiskott-Aldrich syndrome, or bronchopulmonary aspergillosis)
• Pregnancy or lactation
• Platelet count ≤ 110,000/mm^3 or ≤ 110 x 10^9/L at screening or the qualifying run-in visit
• Clinically significant laboratory abnormalities, which would limit participation in the study or interfere in the interpretation of study, or affect subject safety, and evaluations at screening or the qualifying run-in visit
• Treatment with an investigational drug within 1 month of screening or during the run-in period