A Study of huMAb OX40L in the Prevention of Allergen-Induced Airway Obstruction in Adults With Mild Allergic Asthma

Inclusion Criteria: * Weight between 50 and 125 kg * Mild, stable allergic asthma * History of episodic wheeze and shortness of breath * FEV1 at baseline ≥ 70% of the predicted value * For women of childbearing potential, agreement to use an effective means of contraception while enrolled in the study * For men with partners of childbearing potential, willingness to use condoms with spermicide during treatment * Ability to comprehend and follow all required study procedures * Positive skin prick test to common aeroallergens (e.g., cat, dust, mite, grass, and pollen) * Positive allergen-induced early and late airway bronchoconstriction Exclusion Criteria: * A worsening of asthma or a respiratory tract infection within 6 weeks preceding study entry * Acute infection (including viral infection) within the 6 weeks preceding dosing (8 weeks for respiratory infections) or any ongoing chronic infection * History of recurrent bacterial infection as an adult or history or presence of any chronic infectious condition, including (but not limited to), tuberculosis, parasitic infection, etc. * Lung disease other than mild allergic asthma * History of heart, lung, kidney, liver, neurologic or chronic infectious disease * Concomitant disease or condition, which could interfere with the conduct of the study, including, but not limited to, cancer, alcoholism, drug dependency or abuse, or psychiatric disease * History of serious adverse reaction or hypersensitivity to any drug * Pregnancy or lactation or positive serum pregnancy test at screening * Chronic use of any other medication for treatment of allergic lung disease other than short-acting β2-agonists or ipratropium bromide * Current (or history of) treatment with a monoclonal antibody or chimeric biomolecule within the past 5 months (5 half-lives of the drug), including omalizumab * Regular use of tobacco products of any kind or within the previous 6 months, or smoking history \> 10 pack-years