This is a multicenter, randomized, double-blind, placebo-controlled study designed to demonstrate the safety and efficacy of MILR1444A compared with placebo in reducing the airway reaction to an inhaled aeroallergen solution in adult patients with mild allergic asthma. The study will randomize approximately 24 patients at five study centers. In the event of patient discontinuation from the study, additional patients may be enrolled at the discretion of the Sponsor.

Inclusion Criteria:

• Meet criteria for the diagnosis of allergic asthma
• Diagnosis of asthma ≥ 6 months
• Currently treated with only intermittent short-acting inhaled β-adrenergic agonists
• Body weight between 40-120 kg
• Normal chest X-ray within 2 years of screening

Exclusion Criteria:

• Require daily controller medication for asthma
• History of hypersensitivity to the study drug or to drugs with similar chemical structures or to any ingredients, including excipients of the study medication or drugs related to MILR1444A (e.g., monoclonal antibodies, polyclonal gamma globulin)
• Documented medical history of anaphylaxis
• Immunotherapy currently or within the past 3 months prior to screening
• Lung disease other than mild allergic asthma
• Previous treatment with other investigational drugs within 30 days or 5 half-lives prior to the screening visit, whichever is longer
• Pregnant or lactating
• Significant concurrent medical illness other than asthma
• Clinically significant abnormality on ECG at the screening visit
• Smoked in the previous 6 months or have a history of smoking more than 10 pack-years
• History of helminthic infection