A Study to Evaluate the Effectiveness and Safety of MEDI-528 in Adults

Inclusion Criteria

Subjects must meet all of the following criteria:

• Male or female
• Age 18 through 65 years at the time of screening
• Written informed consent and any locally required authorization obtained from the subject prior to performing any protocol-related procedures, including screening evaluations
• Female subjects of childbearing potential who are sexually active with non-sterilized male partner must use adequate contraception from screening through the end of the study. An acceptable method of contraception is defined as one that has no higher than a 1% failure rate. Sustained abstinence is an acceptable practice; however, periodic abstinence, the rhythm method, and the withdrawal method are not acceptable methods of contraception
• Non-sterilized males who are sexually active with a female of child-bearing potential must use adequate contraception from screening through the end of the study
• Females or female partners not of childbearing potential must have been surgically sterilized (eg, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or postmenopausal (defined as at least 1 year since last regular menses)
• Sterilized males must be at least 1-year post vasectomy and have obtained documentation of the absence of sperm in the ejaculate
• Weight ≥ 45 kg but ≤ 120 kg and body mass index (BMI) between 18 and 35 kg/m2
• Physician-diagnosed asthma by medical chart
• Currently taking inhaled corticosteroids (ICS) or is a candidate to receive ICS per Expert Panel Report (EPR)-3
• Pre-bronchodilator forced expiratory volume in 1 second (FEV1) value ≥ 40% at Day -28 and Day 1
• A post-bronchodilator increase in FEV1 and/or FVC ≥ 12% and ≥ 200 mL at Day -28 OR meeting any one of the following criteria:
• Proof of post-bronchodilator reversibility of airflow obstruction ≥ 12% documented within 36 months prior to randomization or proof of a positive response to a methacholine challenge documented within 36 months prior to randomization; OR
• Proof of partial reversibility of ≥ 8% to 15 on the Hospital Anxiety and Depression Scale (HADS) at either Day-28 or Day 1.
• History of suicidal behavior in the previous 3 years as measured by the Columbia Suicide Severity Rating Scale (C-SSRS) at Day -28.
• Acute illness other than asthma at the screening and randomization visits
• History of an active infection within 28 days before and during the screening period, or evidence of clinically significant active infection, including ongoing chronic infection
• History of ingestion of untreated water in a location known to be infected with parasites, resulting in acute or chronic diarrhea; history of recent travel to areas where parasite infestations are endemic within 6 months before screening; or a diagnosis of parasitic infection within 6 months before screening
• Use of immunosuppressive medication (except oral prednisone up to a dose of 20 mg every other day or equivalent [eg, 10 mg a day or 5 mg twice a day] and inhaled and topical corticosteroids) within 28 days before randomization
• Receipt of immunoglobulin or blood products within 28 days before randomization
• Plans to donate blood during the entire study period
• Donated blood or has had a blood transfusion within 28 days before screening
• Receipt of any non-biological study drugs or interventional therapy (including surgical procedures) within 28 days of the first dose of investigational product in this study
• Receipt of any biologicals including MEDI-528 within 5 half-lives before the first dose of investigational product in this study
• History of any known immunodeficiency disorder
• A positive hepatitis B surface antigen, or hepatitis C virus antibody, as determined by medical history and/or subject's verbal report
• A positive human immunodeficiency virus test or is taking antiretroviral medications, as determined by medical history and/or subject's verbal report
• A live attenuated vaccination receiv