A Study to Assess Pharmacokinetics, Safety and Tolerability of Multiple Doses of CAT-354 in Subjects With Moderate Asthma

Inclusion Criteria: * Males or infertile females * Subjects with asthma, well controlled on inhaled corticosteroid and taken as required (PRN) short acting beta 2 agonist therapy only * Unchanged dose of inhaled corticosteroid for 3 months prior to Day 0 and no expected need for change in dose during study * Forced expiratory volume in 1 second (FEV1) greater than or equal to 80% predicted at Screening (Baseline) * 18-60 years * General Practitioner diagnosis of asthma of 1 year's minimum duration (with respect to Day 0) * No significant abnormality on clinical examination or medical history (excluding atopic skin signs, symptoms and history) * 12-lead electrocardiogram with no clinical significant abnormality * Clinical chemistry hematology and urinalysis results within the laboratory reference ranges or deemed not clinically significant by the Investigator * A negative screen for drugs of abuse and alcohol * Body weight between 50-120 kg * Subjects aged between 18-40 years inclusive must have body mass index (BMI) 18-32 kilogram per square meter (kg/m\^2) inclusive. Subjects aged between 41-60 years must have BMI between 18-30 kg/m\^2 inclusive. Exclusion Criteria: * Active concomitant disease, with exception of eczema * Expected onset of seasonal allergy before the administration of the last dose of study medication * History of severe exacerbation within 3 years of Day 0 * Recorded use of inhaled short acting beta 2 agonist medication for symptoms within 14 days of Day…