Real-world safety and effectiveness of omalizumab in Japanese patients with chronic spontaneous urticaria: A post-marketing surveillance study

The safety and efficacy of omalizumab in chronic spontaneous urticaria (CSU) patients has been established, but real-world long-term data remain scarce, especially in Japan.52-week, open-label, single-arm, observational study evaluated the safety and effectiveness of first-time omalizumab in Japanese CSU patients responding inadequately to conventional therapies.Overall, 235 of 280 patients completed the study. Most patients were aged ≥ 18 and 65 years; adolescents (≥ 12 and ≤ 18 years) accounted for 9.6% of the total population. The mean ± standard deviation (SD) duration of CSU at baseline was 1.6 ± 3.1 years; 46.1% of patients had had CSU for6 months. At baseline, the mean ± SD of Urticaria Control Test (UCT) score, Weekly Urticaria Activity Score (UAS7), and Dermatology Life Quality Index (DLQI) were 5.1 ± 3.2, 25.2 ± 11.9, and 8.4 ± 5.9, respectively. The mean ± SD duration of the observation period was 330.3 ± 86.2 days. Relapse was reported in 65 patients, 51, 9, and 5 of whom required retreatment with omalizumab 1, 2, and ≥ 3 times, respectively. The incidence of adverse events (AEs), serious AEs, and adverse drug reactions (ADRs) was reported in 11.8%, 1.4%, and 3.9% of patients, respectively. The most common AEs were urticaria (1.8%) and eczema (1.1%). No adolescents experienced ADRs. A cumulative of 92.8% of patients responded in the Physician's Global Impression of Change, with 81.3%, 75.0%, and 95.1% of patients achieving UCT ≥ 12, UAS7 ≤ 6, and DLQI ≤ 5 up to Week 52, respectively.This study supports the safety and effectiveness of omalizumab in CSU patients who responded inadequately to conventional therapies in real-world clinical practice in Japan.