Omalizumab treatment and outcomes in Chinese patients with chronic spontaneous urticaria, chronic inducible urticaria, or both

Abstract

Background: Chronic urticaria (CU) is a common skin disorder, which can be further divided into chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). Omalizumab is effective and safe for difficult-to-treat CSU based on clinical trials. However, there are limited data comparing the therapeutic effect of omalizumab for patients with CSU, CIndU, and CSU plus CIndU. Meanwhile, there is still no reliable predictor for treatment response or relapse. Our study was conducted to collect real-world clinical data on omalizumab treatment in patients with CSU, CIndU, and both.

Methods: This was an observational, retrospective chart review of patients with CU initiating omalizumab treatment between February 2018 and May 2020 (maximum 28 months follow-up).

Results: A total of 138 patients were included, 87 with CSU alone, 33 with different forms of CIndU, and 18 with both. A total of 87.0% (n = 120/138) of the CU patients responded to omalizumab therapy, among which 65.2% (n = 90/138) of the patients showed complete response and 21.7% (n = 30/138) of the patients showed partial response. The therapeutic effect and speed of onset of effect for omalizumab were comparable among patients with CSU, CIndU, or both. Autologous serum skin test (ASST)-positive patients were more likely to show a slow response to omalizumab therapy ( P = 0.043). Non-responders had lower baseline total IgE levels (35.0 vs 121.5 kU/L, P < 0.001). The proportion of patients with low total IgE levels in non-responders was significantly higher than that of responders (61.1% vs. 14.5%, P < 0.001). Also, more non-responder patients had elevated thyroid autoantibodies than responders (50.0% vs. 23.0%, P = 0.041). The median ratio of serum IgG-anti-TPO to serum total IgE in non-responders was significantly higher compared with responders (1.22 vs. 0.09, P < 0.001). Non-responders also had shorter treatment periods (4.5 vs 6.0 months, P = 0.035) compared with responders. Two of 3 patients (67.4%, n = 29/43) experienced relapse after ceasing omalizumab therapy. These patients had longer disease durations (52.0 vs. 15.0 months, P = 0.007) and higher baseline total IgE levels (179.9 vs. 72.5 kU/L, P = 0.020) than patients who did not relapse. We reinitiated omalizumab treatment for 10 relapsed patients, all of them reported a rapid response after the first injection within the first 4 weeks of retreatment.

Conclusion: Omalizumab is highly effective in patients with difficult-to-treat CSU, CIndU, or both. Responders tend to have unique immunological features and longer treatment periods. Patients with higher baseline total IgE levels and longer disease durations are more likely to experience rapid relapse after discontinuation of omalizumab.

Keywords: Chronic urticaria; Dermatology life quality index; Omalizumab; Urticaria control test.

Fig. 1

A. The proportion of CU patients with uncontrolled (UCT<12) or controlled (UCT ≥ 12) disease. B. The proportion of CU patients with different QoL impairment status according to DLQI score. Abbreviations: CU: chronic urticaria; QoL: quality of life; UCT: urticaria control test

Fig. 2

A. The proportion of responders in patients with CSU, CIndU, or both during treatment period (n = 138). B. Kaplan-Meier curves showing the proportion of responders with positive and negative ASST over time. Abbreviations: ASST: autologous serum skin test; CSU: chronic spontaneous urticaria; CIndU: chronic inducible urticaria

Fig. 3

A. UCT scores in patients re-treated with omalizumab (n = 10). B. UAS7 scores in patients re-treated with omalizumab (n = 9). Abbreviations: UAS7: urticaria activity score 7; UCT: urticaria control test