Background: Clinical trials have shown the efficacy of omalizumabs efficacy in refractory chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), but real-life management strategies are lacking.
Aim: To assess the long-term efficacy and safety of omalizumab, and to identify predictive factors and optimum dosage regimens.
Methods: This was a prospective study of 13 patients (11 women, 2 men) with severe CSU [weekly urticaria activity score (UAS7) > 28] resistant to anti-H1 antihistamines. Patients were started on omalizumab 150 mg subcutaneously every 4 weeks. Dose and interval between administrations were adjusted according to clinical response (189 administrations; treatment duration range 2-38 months).
Results: Mean UAS7 was 36.3 ± 5.4. Of the 13 patients, all had experienced angio-oedema, while in addition, 7 had delayed pressure urticaria (DPU) and 1 had solar urticaria (SU). After omalizumab treatment, 4 (30.8%) of the 13 patients had complete response (CR), and the remaining 8 (61.5%) had partial response. CR was achieved with a dose of 150 mg every 4 (n = 2 patients) or 5 (n = 2) weeks. One of these patients remained disease-free after stopping treatment. Partial responses were achieved with 150 mg every 4 weeks (n = 4) and with 300 mg (n = 4) at intervals of 5 weeks (n = 1), 4 weeks (n = 2) or 3 weeks (n = 1). Only one patient (7.7%) did not show significant improvement, despite a dose of 300 mg every 4 weeks. There were no significant differences in epidemiological, clinical and laboratory data between the different response groups. Only two adverse events were observed: one was mild headache and the other was severe angio-oedema and aggravation of urticaria within 6 h of omalizumab administration.
Conclusion: Omalizumab dose and interval between administrations could be individualized for long-term management of CSU.
© 2017 British Association of Dermatologists.