Sustained Safety and Efficacy of Ligelizumab in Patients with Chronic Spontaneous Urticaria: A One-Year Extension Study.

Background Ligelizumab, a next-generation, humanized anti-immunoglobulin E (IgE) monoclonal antibody is in development as a treatment for patients with chronic spontaneous urticaria, whose symptoms are inadequately controlled with standard-of-care therapy. Objective To evaluate the long-term safety and re-treatment efficacy of ligelizumab 240 mg in patients who completed the core study and extension study. Methods This open-label, single-arm, long-term Phase 2b extension study was designed to assess patients who were previously administered various doses of ligelizumab, omalizumab or placebo in the Phase 2b, dose-finding core study and who presented with active disease after Week 32. In the extension study, patients received ligelizumab 240 mg subcutaneously every 4 weeks, for 52 weeks and were monitored post-treatment for 48 weeks. Results Overall, ligelizumab was well-tolerated with no newly identified safety signals. A total of 95.4% (226/237) screened patients received ligelizumab 240 mg in the extension study; 84.1% (190/226) of patients experienced at least one treatment-emergent adverse event. Most reported events were mild (41.6%) or moderate (35.8%) and mostly unrelated to the study treatment. At Week 12, 46.5% of patients had a complete response increasing to 53.1% after 52 weeks. Following 52 weeks of extension study treatment, 75.8% (95% confidence interval, 69.9, 81.3) of patients had cumulative complete responses. The median time to relapse in complete responders was 38 weeks. Conclusion The long-term safety profile of ligelizumab 240 mg in patients with chronic spontaneous urticaria was consistent with the core study and re-treatment efficacy was shown. Trial Registration: ClinicalTrials.gov Identifier: NCT02477332 and NCT02649218.