A Study to Evaluate the Dosing of AMG 827 for Subjects With Inadequately Controlled Asthma

プラセボコンパレーター：Placebo

Participants will receive the matching placebo administered as subcutaneous (SC) injections at Day 1 and weeks 1, 2, 4, 6, 8, and 10.

薬：Placebo

SC injection.

実験的：AMG 827 140 mg

Participants will receive AMG 140 mg administered as SC injections at Day 1 and weeks 1, 2, 4, 6, 8, and 10.

薬：AMG 827

SC injection.

実験的：AMG 827 210 mg

Participants will receive AMG 210 mg administered as SC injections at Day 1 and weeks 1, 2, 4, 6, 8, and 10.

薬：AMG 827

SC injection.

実験的：AMG 827 280 mg

Participants will receive AMG 280 mg administered as SC injections at Day 1 and weeks 1, 2, 4, 6, 8, and 10.

薬：AMG 827

SC injection.

Change From Baseline in Asthma Control Questionnaire (ACQ) Composite Scores to Week 12

The ACQ is an instrument used in clinical research and practice to evaluate asthma control/impairment.

It is a validated composite score that assesses disease control by evaluating 7 questions: night time awakenings, asthma symptoms upon awakening, activity limitation, shortness of breath, wheeze frequency, short-acting bronchodilator use, and forced expiratory volume in 1 second (FEV1).

The response options for all these questions range from zero (no impairment/limitation) to six (total impairment/limitation) scale. The total score is obtained by adding the value from each question and dividing by the number of questions. Higher scores indicates worsening of condition and a negative change from baseline indicates improvement.

Change From Baseline in Pre- and Post-Bronchodilator Forced Expiratory Volume in 1 Second (FEV1)

FEV1 is the volume of air that can forcibly be blown out in one second, after full inspiration. FEV1 was performed both pre and post-administration of bronchodilator treatment at Baseline and Week 12.

Change From Baseline in AM and PM Peak Expiratory Flow Rate (PEFR) to Week 12

Change From Baseline in the Frequency of Rescue Short Acting β-Agonist (SABA) Use to Week 12

Participants recorded SABA use for 1 week prior to randomization (baseline) and the average number of days recorded was subtracted from average days of SABA use across 12 week intervention period.

Change From Baseline in Daily Asthma Symptom Score to Week 12

Participants recorded their daily asthma symptoms in their electronic diaries (Ediary). It included 7 questions: frequency of night time awakening, time awake at night, wheezing, shortness of breath, cough, chest tightness and activity limitation.

Daily asthma symptoms score is the sum of 7 individual scores (with the total score ranging from 0-21).

Higher scores indicates worsening of condition and a negative change from baseline indicates improvement.

Change From Baseline in Asthma Quality of Life Questionnaire (AQLQ) Score at Week 12

The AQLQ is the most commonly used asthma specific instrument and includes evaluations of both symptom and quality of life measures. The 32-item instrument measures 4 domains affected by asthma including activity limitations, emotional function, exposure to environmental stimuli, and symptoms (Mitchell EA et al, 1997, Juniper et al, 1994, Christie MJ et al, 1993, Juniper et al, 1993).

Participants were asked to recall their experiences during the last 2 weeks and to respond to each question on a 7-point scale (7=no impairment, 1=severe impairment). The overall score = mean of the responses to the 32 questions.

Higher scores indicate "better quality of life" and a positive change from baseline indicates improved symptoms.

Proportion of Asthma Symptom-free Days

Asthma symptom-free days were defined as a participant having a score of zero in their daily asthma symptom score. Asthma symptom-free days without SABA use were defined as a participant having a score of zero in their daily asthma symptom score and no SABA use.

The proportion of asthma symptom-free days was calculated as the number of asthma symptom-free days over the number of days in the double-blind treatment period (12 weeks).

Time to Maximum Observed Concentration (Tmax) of AMG 827 at Week 8 to 10

Maximum Observed Concentration (Cmax) of AMG 827 at Week 8 to 10

Area Under the Concentration-time Curve During the Dosing Interval (AUCtau) of AMG 827 at Week 8 to 10