An Extension Study of Long-term Efficacy, Safety and Tolerability of Remibrutinib in Chronic Spontaneous Urticaria Patients Who Completed Preceding Studies With Remibrutinib

The purpose of this extension study is to collect long-term efficacy, safety and
tolerability data on remibrutinib in a selected group of participants with Chronic
Spontaneous Urticaria (CSU) who previously completed the treatment phase of remibrutinib
preceding Phase 3 studies.

This study will also fulfill the Novartis commitment to provide post-trial access to
participants who have completed the preceding Phase 3 studies, where applicable. This is a global, multicenter, randomized, double-blind, placebo-controlled, randomized
withdrawal Phase 3b extension study, followed by long-term open label treatment cycles to
assess the efficacy, safety and tolerability of remibrutinib in adult participants with
CSU inadequately controlled by H1-AH. The study comprises 2 Epochs. Epoch 1 is the
initial study period for participants who completed preceding remibrutinib Phase 3
studies. Epoch 1 comprises of a 24-week randomized withdrawal period with remibrutinib or
placebo for patients with UAS7<16 OR a 24 week Open-label treatment period with
remibrutinib for patients with UAS7≥16.

Participants will be randomized in a 1:1 ratio to enter the double-blind
placebo-controlled 24-week withdrawal phase. In case of relapse (UAS7≥16) in the blinded
group, participants enter the (Re-)treatment period Epoch 1 and receive 24 weeks of
Open-label treatment with remibrutinib. At the end of the (Re-)treatment period Epoch 1,
participants will move to Epoch 2.

Epoch 2 is the second subsequent study period and consists of 24-week cycles that could
either encompass treatment-free Observation and/or Open-label (Re-)treatment periods with
remibrutinib, with or without background H1-AH.

In case of relapse (UAS7≥16) during an Observation period, participants enter the next
(Re-)treatment period and receive 24 weeks of treatment with remibrutinib. Participants
completing an Observation period 2/3/4/5 with a UAS7≤6 will complete the study.
Participants with a UAS7 >6 -<16 can enter the next (Re-)treatment period if continuous
treatment is considered necessary and beneficial for the individual participant. For
participants with a UAS7<16 that enter the next (Re-)treatment period, remibrutinib
monotherapy treatment (without background H1-AH) is required.