24 weeks double-blind randomized placebo-controlled trial to evaluate efficacy, PK, safety of LOU064 in adolescents (12 - <18) with CSU and inadequate response to H1-antihistamine followed by optional 3 years open-label extension and an optional 3 years safety long-term treatment-free follow-up

INTERVENTION: Product Name: ‐, Product Code:R06A, Pharmaceutical Form: ‐, Other descriptive name: , Strength: , Product Name: LOU064, Product Code:PRD10219597, Pharmaceutical Form: FILM‐COATED TABLET, Other descriptive name: , Strength: , Product Name: Placebo to LOU064 25 mg film‐coated tablet, Product Code:N/A, Pharmaceutical Form: N/A, Other descriptive name: N/A , Strength: , Pharmaceutical form of the placebo: N/A , Product Name: LOU064, Product Code:PRD10219598, Pharmaceutical Form: FILM‐COATED TABLET, Other descriptive name: , Strength: , Product Name: Placebo to LOU064 10 mg film‐coated tablet, Product Code:N/A, Pharmaceutical Form: N/A, Other descriptive name: N/A , Strength: , Pharmaceutical form of the placebo: N/A , Product Name: ‐, Product Code:H02A, Pharmaceutical Form: ‐, Other descriptive name: , Strength: CONDITION: Chronic Spontaneous Urticaria ; MedDRA version: 20.0Level: PTClassification code: 10072757Term: Chronic spontaneous urticaria Class: 100000004858 MedDRA version: 20.0Level: PTClassification code: 10072757Term: Chronic spontaneous urticaria Class: 100000004858 Therapeutic area: Diseases [C] ‐ Skin and Connective Tissue Diseases [C17] PRIMARY OUTCOME: Main Objective: To assess the efficacy of remibrutinib versus placebo in CSU with respect to absolute change from baseline in UAS7, ISS7 and HSS7 at Week 12 Primary end point(s): Absolute change from baseline in ISS7, HSS7, UAS7 at week 12 Secondary Objective: To assess pharmacokinetic parameters at Week 12, To assess the proportion of participants achieving disease activity control (UAS7 = 6) at Week 12 and over time who are treated with remibrutinib compared to placebo‐treated participants, To assess the proportion of participants achieving complete absence of hives and itch (UAS7 = 0) at Week 12 and over time who are treated with remibrutinib compared to placebo‐treated participants, To evaluate the efficacy of remibrutinib versus placebo in CSU with respect to change from baseline in CDLQI score at Week 12, To evaluate the efficacy of remibrutinib versus placebo with respect to cumulative number of weeks between baseline and Week 12 during which subjects achieve Angioedema Activity Score Over 7 Days equal to 0 (AAS7 = 0), To assess the safety and tolerability of remibrutinib over 24 weeks, To assess the safety and tolerability of long‐term treatment with remibrutinib in the OLE period SECONDARY OUTCOME: Secondary end point(s):Absolute change from baseline in CDLQI score at Week 12 Secondary end point(s):Absolute change from baseline in UAS7 at Week 12 Secondary end point(s):Achievement of UAS7 = 0 (yes/no) at Week 12 and over time Secondary end point(s):Achievement of UAS7 = 6 (yes/no) at Week 12 and over time Secondary end point(s):Concentration of remibrutinib at Week 12 including Cmax, Tma Xand AUC Secondary end point(s):Number of weeks without angioedema, assessed by the cumulative number of weeks with an AAS7 = 0 response between baseline and Week 12 Secondary end point(s):Occurrence of treatment emergent AEs, SAEs and laboratory and vital signs abnormalities during the core period Secondary end point(s):Occurrence of treatment‐emergent adverse events, serious adverse events and laboratory and vital signs abnormalities during the OLE period INCLUSION CRITERIA: Male and female adolescent participants aged = 12 to < 18 years of age at the time of signing the informed consent., CSU duration for = 6 months prior to screening (defined as the onset of CSU determined by the investigator based on all available supporting documentation), Diagnosis of CSU inadequately controlled by second‐generation H1‐AH at the time of randomization defined as: ‐ The presence of itch and hives for = 6 consecutive weeks prior to screening despite the use of second‐generation H1‐AH during this time period according to local treatment guidelines ‐ UAS7 score (range 0 ‐ 42) = 16, ISS7 score (range 0 ‐ 21) = 6 and HSS7 score (range 0 ‐ 21) = 6 during the 7 days prior to randomization (Day 1), Documentation of hives within three months before randomization (either at screening and/or at randomization; or documented in the participants’ medical history)