D2.352 - Assessing Risk Factors for Relapse Following Omalizumab Discontinuation in Chronic Urticaria

The course and duration of chronic urticaria (CU) are unpredictable, with the potential for relapse even after complete remission. This study aimed to analyze factors that increased the risk of relapse in patients with CU who discontinued omalizumab treatment due to remission but subsequently experienced a relapse.

This observational, multicenter study included patients diagnosed with CU at the Department of Allergy and Immunology of Hacettepe University and the Dermatology Clinic of Coimbra Hospital between 2010 and 2024 who had received continuous omalizumab treatment for at least six months. Patients were divided in two groups according to whether they experienced or not a relapse at least three months after cessation of omalizumab treatment.

The study included a total of 61 patients with CU (82% female), with a mean age of 46.36 ± 14.86 years. Relapse was observed in 23 patients (37.7%), and the median time from cessation of omalizumab to relapse was 8 (range: 4–12) months. Male gender (p=0.014), C-reactive protein levels (CRP) (p < 0.001), CU duration (p < 0.001), and omalizumab treatment duration (p = 0.003) were significantly associated with relapse. In the logistic regression model, an increase in CU duration by one month was found to increase the likelihood of relapse by 1.03% (odds ratio [OR] = 1.033, 95% confidence interval [CI]: 1.004–1.063, p = 0.024), while a shorter duration of omalizumab treatment was associated with a 1.07-fold increase in relapse risk (OR = 0.933, 95% CI: 0.877–0.994, p = 0.031), elevated CRP levels resulted in a threefold increase in this relapse risk (OR = 2.976, 95% CI: 1.244–7.117, p = 0.014).The optimal cut-off values were determined to be 21 months for omalizumab treatment duration (area under the curve [AUC] = 0.72, p = 0.003) and 121 months for CU duration (AUC = 0.90, p < 0.001). 

This study found that prolonged CU duration, elevated CRP levels, and shorter treatment duration with omalizumab were associated with relapse. These findings highlight the importance of individualized treatment strategies in the management of CU.