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

Background: 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. Methods: 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. Results: 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 for < 6 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. Conclusions: 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. (c) 2022 Japanese Society of Allergology. Published by Elsevier B.V.