Omalizumab dosing patterns and drug survival in adult patients with chronic spontaneous urticaria.

BACKGROUND

Omalizumab is an effective treatment for chronic spontaneous urticaria (CSU), but strategies and predictors for guiding long-term management and discontinuation remain limited.

OBJECTIVES

To examine real-world treatment patterns, including dosing modifications and discontinuation, and identify potential predictive factors for these outcomes.

METHODS

This was a retrospective, observational, real-life study of adult patients with CSU treated with omalizumab at a Urticaria Center of Reference and Excellence (UCARE) in Copenhagen, Denmark, between May 20, 2015, and April 4, 2024. The Kaplan-Meier estimator was used to visualize time to discontinuation and dose escalation/reduction (using standard label dosing as reference), and Cox-regressions with hazard ratios (HR) were used to investigate potential predictive variables.

RESULTS

Of 430 patients initiated on omalizumab, 139 (32.4%) escalated treatment, 161 (37.5%) reduced treatment, and 90 (21.0%) discontinued treatment directly from the standard dose. The median survival time for dose escalation was 2 years (95% CI: 1.17-3.55), and the strongest predictor was a positive basophil histamine release assay (BHRA) (HR: 2.79, 95% CI: 1.69-4.61). Fast treatment response (HR: 0.50, 95% CI: 0.33-0.75) and higher baseline UCT scores (HR: 0.89, 95% CI: 0.82-0.97) decreased the risk of dose escalation. The median survival time to dose reduction was 1.2 years (95% CI: 0.98-1.49) and was more likely in males (HR: 1.68, 95% CI: 1.13-2.50) and patients with fast treatment response (HR: 1.66, 95% CI: 1.12-2.48). Median survival time to discontinuation (all reasons) of omalizumab was 3 years (95% CI: 2.35-3.64).

CONCLUSIONS

A considerable proportion of patients with CSU require modifications to the recommended omalizumab dosing regimen. A positive BHRA was the strongest predictor for dose escalation, while male sex and fast treatment response were the strongest predictors for dose reduction. Our study highlights the need for individualized strategies in managing CSU.