Evaluation of: Bousquet J, Rabe K, Humbert M et al. Predicting and evaluating response to omalizumab in patients with severe allergic asthma. Respir. Med. 101(7), 1483-1492 (2007). Among new asthma therapies, omalizumab is the only monoclonal antibody that has been proven to be effective and safe in treating severe, inadequately controlled asthma. Nevertheless, it has been pointed out that not all patients respond to it. This paper analyzes the results of a recent study that was aimed at achieving a more accurate evaluation of the response to omalizumab in patients with severe allergic asthma, by identifying possible pretreatment characteristics that can be predictive of a better and superior response to omalizumab. The results established that it is difficult to predict which patients will gain most benefit from treatment, according to pretreatment baseline characteristics.