Time-course and dose-effect of omalizumab in treating chronic idiopathic urticaria/chronic spontaneous urticaria.

Purpose: Several studies have shown that subcutaneous injections of omalizumab can treat chronic idiopathic/spontaneous urticaria (CIU/CSU) patients by only assessing the efficacy on specific endpoints. This study aimed to quantitatively analyze different doses of omalizumab in CIU/CSU and compare it with ligelizumab.

Methods: Literature searches were performed in PubMed, Embase, and Web of Science databases. A model-based meta-analysis (MBMA) was utilized to develop a model incorporating time since the initiation of treatment and dose for omalizumab, with the change from baseline in Urticaria Activity Score (CFB-UAS7) as the primary efficacy endpoint. The time-course and dose-effect relationship throughout the omalizumab treatment period was analyzed, and the findings were compared with those of the investigational ligelizumab.

Results: The model equation for the CFB-UAS7 was established as E = -E_max × time/(ET₅₀ + time) × (b₀ + b₁ × dose). The estimated values of the model parameters $E_{\max }$ , ${\mathrm{ET}}_{50}$ , $b_0$ , and $b_1$ were -1.16, 1.26 weeks, -9.90, and -0.0361 mg^-1, respectively. At week 12 after the first dose, the model-predicted CFB-UAS7 for 150 mg and 300 mg of omalizumab were -16.0 (95% CI, -17.2 to -14.8) and -21.7 (95% CI, -22.9 to -20.5), respectively. In the PEARL-1 trial, the CFB-UAS7 for 72 mg and 120 mg of ligelizumab were -19.4 (95% CI, -20.7 to -18.1) and -19.3 (95% CI, -20.6 to -18.0), respectively. In the PEARL-2 trial, these values were -19.2 (95% CI, -20.5 to -17.9) and -20.3 (95% CI, -21.6 to -19.0), respectively.

Conclusion: Omalizumab showed a significant dose-dependent effect in the treatment of CSU. Both 72 mg and 120 mg ligelizumab might have the potential to outperform 150 mg (but not 300 mg) omalizumab.