Predicting and evaluating response to omalizumab in patients with severe allergic asthma.

BACKGROUND Omalizumab is a monoclonal antibody indicated for treatment of severe persistent allergic asthma inadequately controlled despite optimal controller therapy. We investigated whether patient selection could be targeted further. METHODS Data from seven randomized controlled omalizumab trials were analyzed to investigate whether pre-treatment patient baseline clinical characteristics could be identified that were predictive of a superior response to omalizumab. We also studied whether patients who respond to omalizumab following a course of treatment could be reliably identified. Univariate/multivariate analyses of INNOVATE data were performed to identify predictive baseline measures and further investigated in efficacy analyses of pooled data from seven studies. The best method of identifying responders to omalizumab following treatment was determined by assessing the ability of various clinical response criteria to identify responders and discriminate patient exacerbation and other outcomes. RESULTS Baseline total immunoglobulin E (IgE) was the only predictor of efficacy in INNOVATE. However, pooled analysis showed treatment benefits irrespective of IgE levels. In omalizumab-treated patients, physician's overall assessment following a course of treatment identified 61% as responders and best discriminated treatment outcomes. CONCLUSION Baseline characteristics do not reliably predict benefit with omalizumab. Physician's overall assessment after 16 weeks of treatment is the most meaningful measure of response to therapy.