Efficacy of omalizumab in cat-allergic patients with moderate-to-severe persistent asthma

Cat allergen (Fel d 1) is a pervasive and common trigger of exacerbations in sensitized patients with IgE-mediated asthma. This study was designed to evaluate the effect on asthma-related outcome measures of adding omalizumab to current treatment in patients with moderate-to-severe persistent asthma and cat allergen sensitivity. A pooled analysis was conducted of two double-blind, placebo-controlled, 28-week pivotal U.S. registration trials. In all patients, asthma was inadequately controlled with moderate-high dose inhaled corticosteroids. Patients were randomized to receive subcutaneous omalizumab (minimum, 0.016 mg/kg per IgE IU/mL every 4 weeks) or matched placebo. The effects of omalizumab on asthma-related outcomes were assessed for patients with cat allergen sensitivity (n = 811), identified by positive skin-prick test. The mean number of asthma exacerbations requiring treatment with systemic steroid bursts in cat allergen-sensitive patients was lower in those receiving omalizumab versus placebo (0.6 versus 1.3, respectively; relative risk = 0.50, p < 0.001). Compared with placebo, omalizumab treatment led to significantly lower asthma symptom scores (least squares means (LSMs) treatment difference [95% confidence interval {CI}]: -0.57 [-0.77, -0.37]; p < 0.001), less rescue medication use (LSMs treatment difference [95% CI]: -0.75 puffs of rescue beta-agonist per day [-1.04, -0.46]; p < 0.001), and improvement in forced expiratory volume in 1 second (LSMs treatment difference [95% CI]: 100.84 mL [51.86, 149.81]; p < 0.001). Patient and investigator global evaluations of treatment effectiveness paralleled these outcomes. Omalizumab improved asthma control by reducing exacerbations and decreasing symptoms in cat-allergic patients with moderate-to-severe persistent IgE-mediated asthma.