Efficacy and predictors of rapid response to omalizumab therapy in patients with seasonal allergic rhinitis: a cohort study

BACKGROUND: The availability of anti-IgE therapy for allergic rhinitis has actualized the need to develop variants of this treatment according to predictors of rapid response and techniques of treatment initiation. AIM: To study the efficacy and predictors of response to omalizumab in patients with seasonal allergic rhinitis. MATERIALS AND METHODS: Patients with moderate or severe seasonal allergic rhinitis in which traditional treatment for at least 3 months was not effective in the previous pollen season or in the current season were included. The decision to prescribe omalizumab was made based on the visual analog scale (VAS) in the previous or current season. The dosage and frequency of administration (every 2 or 4 weeks) were determined according to the table of values provided in the instructions. The patients were observed for 2 months. At follow-up visits (1 and 2 months later), allergic rhinitis symptom control was assessed using VAS and total nasal symptoms score (TNSS). Therapy was considered effective when the VAS remained 30 or decreased 30 after 4 and 8 weeks from the start of therapy, depending on the initiation period. RESULTS: The study enrolled 30 patients with allergic rhinitis history of 14 years, sensitization to 2 groups of allergens in 19 (63.3%) cases and bronchial asthma in 18 (60%). Omalizumab was initiated before the pollen season in 6 (20%) patients and during the season in 24 (80%) patients. After 4 weeks, allergic rhinitis manifestations were controlled in 23 (77%) patients, and by week 8, 100% of the patients with allergic rhinitis had fully responded to therapy. By 4 weeks of follow-up, the severity of allergic rhinitis symptoms on the VAS and TNSS scales decreased by 2.7 and 4.7 times, respectively. The proportion of patients with a slow response by week 4 of therapy was 23%. Body mass index (lower in the slow response group) and history of bronchial asthma (2.6 times longer in the slow responders) were associated with the achievement of this outcome. No adverse events were recorded. CONCLUSIONS: In patients with seasonal allergic rhinitis, omalizumab allows the control of disease manifestations after 4 weeks of therapy with its maintenance in the follow-up. Predictors of rapid response have been revealed; however, their clinical significance requires further study.