*4.2.4 Phase III ligelizumab study*

Currently, two similar trials (PEARL 1 NCT03580356 and PEARL 2 NCT03580369) are ongoing to study the efficacy and safety of ligelizumab (72 mg or 120 mg every 4 weeks) in CSU patients who remain symptomatic despite standard of care treatment [97]. Both are 52-weeks multi-center, randomized, doubleblind, placebo- and active controlled phase III trials and is planned to enroll about 1000 patients for each study.

In addition, a phase IIIb extension study is planned to investigate ligelizumab in adult and adolescent patients with CSU (NCT04210843) [98].

Results from these studies may confirm whether ligelizumab should become an alternative first-line treatment option in H1-antihistamine refractory CSU patients.
