Omalizumab in the severe exacerbations of seasonal allergic rhinitis

BACKGROUND: According to the Federal Clinical Guidelines, patients with severe persistent allergic rhinitis and/or severe exacerbation who failed to respond to third-line pharmacotherapy (antihistamines, leukotriene receptor antagonists, nasal corticosteroids) are advised to consider the administration of omalizumab. However, there is a lack of practical recommendations guiding the regimens and duration of the omalizumab therapy in the severe exacerbation of seasonal allergic rhinitis. AIMS: To assess the efficacy of omalizumab additional therapy in patients with severe exacerbation of allergic rhinitis during the pollen season, and to determine the optimal regimen and duration of treatment. MATERIALS AND METHODS: This is an open observational uncontrolled prospective single-center study. 10 adult patients with severe exacerbation of seasonal allergic rhinitis due to birch pollen were selected for the study. All of them received the third-line of therapy according to Federal Clinical Guidelines and had absence or incomplete control: Total nasal symptom score 2. All of them were treated with omalizumab. The dose and regime were prescribed according to instructions that took into account the overall IgE level, as well as the patients weight. Daily symptom diaries and the need for rescue medication levels were evaluated. The primary endpoint had a decrease in the Combined Medical and Symptom Score mean. RESULTS: The additional omalizumab treatment improved allergic rhinitis control for all patients and also reduced the rescue medication (TNSS 1.8 [95% CI 1.562.04]; р 0.001, and CMSS 2.12 [95% CI 1.742.5]; р 0.001, by the end of 1 week after the first omalizumab injection; TNSS 2.53 [95% CI 2.053.01]; р 0.0001, and CMSS 5.22 [95% CI 4.745.7]; р 0.001, by the end of four weeks, respectively). It was noted that the omalizumab effect realization occurs for some time (37 days). Due to short-season pollen for birch (12 months), the duration of treatment in our study did not exceed one month, so we managed to achieve complete control over the symptoms in all patients by the omalizumab with a small multiplicity of injections (12 injections). No adverse events were registered during the study. CONCLUSION: Omalizumab additional therapy in patients with severe exacerbation of allergic rhinitis allows control of all symptoms. Taking into account the mechanism of its action, omalizumab should be administered at least a week before the expected pollen season in patients with severe exacerbation (according to the previous seasons) who did not complete their allergen-specific immunotherapy on time, and continue therapy till the end of the pollen season.