This study was designed to provide one year efficacy and safety data for subcutaneous (SC) omalizumab, compared to placebo in children (6 to < 12 years) with moderate to severe persistent asthma who have inadequate asthma control despite treatment according to National Heart, Lung and Blood Institute (NHLBI) step 3 or 4 (at least medium dose inhaled corticosteroids with or without other controller asthma medications).