Omalizumab in Chronic Spontaneous Urticaria (CSU): Real-Life Experience in Dose/Interval Adjustments and Treatment Discontinuation.

BACKGROUND: Data on real-life experience with omalizumab dose/interval adjustments are still limited, as well as on omalizumab discontinuation.

OBJECTIVE: To evaluate efficacy and safety of omalizumab dose/interval adjustment in a Portuguese cohort of patients with chronic spontaneous urticaria (CSU) and to characterize those who discontinued omalizumab.

METHODS: A retrospective study of patients who started omalizumab for CSU at a Portuguese Urticaria Center of Reference and Excellence (UCARE) was conducted between 2009 and 2021. Response criteria were based on a weekly Urticaria Activity Score (UAS7) <7 points (partial: UAS7 7-15 points; nonresponders: UAS7 >15 points) and minimal important difference >10 points.

RESULTS: A total of 138 patients were enrolled in the study; 83% of them were women, and the median age was 49 years (interquartile range: 40-58 years). On 300 mg q4 weeks, 96 (70%) patients were responders, 29 (21%) partial responders, and 13 (9%) nonresponders. After dose/interval adjustments (up to 600 mg q2 weeks), 108 (78%) were responders, 27 (20%) partial responders, and 3 (2%) nonresponders. No adverse events were reported. Updosing was more frequent in patients with angioedema, body mass index >30 kg/m2 , positive basophil activation test, and autologous serum test. A total of 71 (51%) patients lengthened interval, presenting higher median pre-omalizumab D-dimer (0.2 vs 0 mcg/mL, P = .038) and C-reactive protein (0.3 vs 0.1 mg/dL, P = .030) values than those with a standard dose. In total, 37 patients (27%) stopped omalizumab, but 14 (38%) of them needed retreatment on average 11 months after discontinuation. Patients with angioedema and a longer omalizumab duration had higher chance of relapse.

CONCLUSIONS: Omalizumab dose and/or interval adjustment is effective and safe and should be implemented in partial/nonresponders for response improvement and in responders for further discontinuation. A protocol for regimen adjustments is proposed.