Study of Efficacy and Safety of Ligelizumab in Chronic Spontaneous Urticaria Patients Who Completed a Previous Study With Ligelizumab

This was a Phase IIIb multi-center, double-blinded and open-label extension study to evaluate efficacy and safety of ligelizumab retreatment with H1-AHs background therapy with an option for ligelizumab monotherapy (i.e., discontinuation of background H1-AH) in adult and adolescent CSU participants who had completed one of the preceding studies, in the setting of retreatment and self-administration. Participants with weekly urticaria activity score (UAS7) \< 16 during screening entered the first (investigational treatment-free) observation period (OBS1), with a duration up to 36 weeks. Participants with UAS7 ≥ 16 during screening or OBS1 were assigned to 1 of the 2 treatment arms and entered the treatment period (first half treatment period, referred to as TRT1). The first half treatment period (TRT1) was 52 weeks (from Week 0 to Week 52). Participants remained on the same H1-AH background medication they were taking in the preceding studies. TRT1 was divided into: * The first 12 weeks in TRT1: i. participants transitioning from CQGE031C2302 (NCT03580369) and CQGE031C2303 (NCT03580356) previously treated with ligelizumab 72 mg liquid in vial subcutaneously (s.c.) every 4 weeks (Q4W) were treated with the same dose regimen in a double-blind manner in this extension study; ii. all other participants transitioning from CQGE031C2302 (NCT03580369) and CQGE031C2303 (NCT03580356) were treated with ligelizumab 120 mg liquid in vial s.c., Q4W, in a double-blind manner in this extension study; iii. participants transitioning from CQGE031C1301 (NCT03907878) and CQGE031C2202 (NCT03437278) were treated with ligelizumab 120 mg liquid in vial s.c., Q4W in an open-label manner in this extension study. * After the first 12 weeks in TRT1 (and up to Week 52), all participants were switched to ligelizumab 120 mg s.c. pre-filled syringe (PFS) Q4W in an open-label manner and they were offered an opportunity to self-administer ligelizumab outside the clinic. The second half of the treatment period (TRT2) was 52 weeks (from Week 52 to Week 104). Participants with UAS7\>6 and \<16 or with UAS7 ≥ 16 for whom the benefit-risk was deemed as positive by the investigator at Week 52 of TRT1 were transitioned to the TRT2 (ligelizumab 120 mg s.c. Q4W PFS) unless a decision to stop treatment was made based on a risk-benefit assessment. They were not allowed to discontinue H1- AH background medication. Participants with UAS7 ≤ 6 at Week 52 of TRT1 entered the second (investigational treatment-free) observation period (OBS2) for up to 52 weeks and remained on the same H1-AH background medication they were taking in the preceding studies. Participants with UAS7 ≤ 6 at Week 52 of TRT1 who entered the second observation period (OBS2) and relapsed (UAS7 ≥ 16) were transitioned to the TRT2 and were also offered the opportunity to discontinue their H1-AH background medication (i.e. ligelizumab 120 mg s.c. q4w PFS monotherapy) after 12 weeks in TRT2. Participants who entered the OBS2 and did not relapse (UAS7\<16) exited the study at the end of the OBS2 period. Finally, participants who were in TRT2 entered the post-treatment follow-up period after treatment discontinuation, with duration of 12 weeks (for participants who did not complete a continuous 104-week treatment) or 52 weeks (for participants who completed the full 104-week treatment period without interruption). Participants who decided to remain on H1-AH background medication continued to use H1-AH background medication. Participants who decided to go off H1- AH background medication continued to remain off.