A Phase 2A Study to Evaluate the Safety and Effect on Exercise Challenge Testing of MEDI-528 in Adults With Asthma

Inclusion Criteria: Patients must meet all of the following criteria: * Male or female adults, age 18 through 50 years at the time of screening; * Weight 50-100 kg and body mass index ≤ 35; * Written informed consent obtained from the patient prior to receipt of any study medication or beginning study procedures; * Documented clinical history of asthma and receiving stable treatment for ≥ 1 month prior to Study Day 0; * Airway hyperresponsiveness (AHR) on methacholine inhalation challenge testing at screening (or a documented history within the past 6 months), with provoking concentration of methacholine to cause a 20% fall in FEV1(subscript) (PC20) ≤ 8 mg/mL (Crapo, 2000); * Exercise-induced bronchoconstriction (EIB) with a decrease in FEV1 (subscript) of ≥ 15% from pre-exercise challenge testing level at screening; * Able to provide spirometry readings that meet American Thoracic Society (ATS) and European Respiratory Society (ERS) standards (Miller, 2005); * Women of childbearing potential, unless surgically sterile or at least 1 year post-menopausal, must use two effective methods of avoiding pregnancy (including oral, transdermal, or implanted contraceptives, intrauterine device, female condom, spermicide, diaphragm, cervical cap, abstinence, contraceptive foam, or use of a condom by the sexual partner or sterile sexual partner) from screening through Study Day 0, and must agree to continue using such precautions through Study Day 150. Cessation of birth control after this point should be discussed with a responsible physician. Men, unless surgically sterile, must likewise use an effective method of birth control (condom with spermicide) and must agree to continue using such precautions from screening through Study Day 150; * Able to complete the study period, including follow-up period, of up to approximately 150 days; and * Willing to forego other forms of experimental treatment and study procedures during the study and for 30 days after the follow-up period is completed. Exclusion Criteria: Patients must have none of the following criteria: * Receipt of MEDI-528 in any previous clinical study; * History of allergy or reaction to any component of the study drug formulation; * Lung disease other than asthma (eg, chronic obstructive pulmonary disease, cystic fibrosis); * Forced expiratory volume in 1 second (FEV1-subscript) \< 70% of predicted values at screening; * Use of systemic immunosuppressive drugs including systemic corticosteroids, ICS with doses \> 800 μg/day budesonide (or another ICS of equivalent dose), long-acting β2 agonists, cromolyn sodium, nedocromil sodium, leukotriene receptor antagonists, theophylline, or omalizumab from screening through Study Day 150; * Current use of any β-adrenergic antagonist (eg, propranolol); * Any disease or illness, other than asthma, that is likely to require the use of systemic corticosteroids during the study period; * Acute illnesses or evidence of significant active infection, such as fever ≥ 38.0°C (100.5°F) from screening through Study Day 0; * Current allergy vaccination therapy (desensitization immunotherapy); * Receipt of any investigational drug therapy within 30 days or any biologic(s) within 5 half-lives of the agent prior to screening; * Pregnancy (women of child bearing potential, unless surgically sterile or at least 1 year postmenopausal, must have a negative serum and urine pregnancy test at screening before methacholine inhalation challenge testing and a negative urine pregnancy test prior to study drug administration on Study Day 0); * Breastfeeding or lactating woman; * Evidence of infection with hepatitis B or C virus or HIV-1 or HIV-2, or active infection with hepatitis A; must have negative HIV-1, HIV-2, hepatitis A, B, and C tests at screening; * History of cancer other than basal cell carcinoma of the skin or cervical carcinoma-in-situ treated with apparent success with curative therapy more than 1 year prior to Study Day 0; * History of primary immunodeficiency * History of pancreatitis or currently active gastroduodenal ulcer; * Current use of tobacco products or a history of use of tobacco products of more than one cigarette per month or equivalent within 1 year prior to randomization or history of smoking of ≥ 10 pack-years; * History of life-long urinary retention; * History of anaphylaxis (defined as immediate life-threatening event requiring medical invention); * Elective surgery planned from screening through Study Day 150; * Clinically significant abnormality, as determined by the investigator, on 12-lead ECG or chest radiograph at screening; * History of any disease, evidence of any current disease (other than asthma), any finding upon physical examination, or any laboratory abnormality, that, in the opinion of the investigator or medical monitor, may compromise the safety of the patient in the study or confound the analysis of the study; or * Any employee of the research site who is involved with the conduct of the study.