Rilzabrutinib for the Treatment of Chronic Spontaneous Urticaria in Patients Who Remain Symptomatic Despite the Use of H1 Antihistamine

Who can take part

• Participants who had a diagnosis of CSU refractory to H1-AH at the time of randomization
• Diagnosis of CSU ≥3 months prior to screening visit (Visit 1)
• The presence of itch and hives for ≥6 consecutive weeks at any time prior to screening visit (Visit 1) despite the use of H1-AH during this time period
• Participants using a study defined H1-AH for CSU treatment. For participants on stable doses of non-study-approved H1-AH, investigators may switch participants to an equivalent dose of a study-approved H1-AH maintenance medication
• Participants who were omalizumab naïve OR omalizumab-incomplete responders
• Participants must be willing and able to complete a daily symptom e-diary for the duration of the study
• During the 7 days before randomization: UAS7 ≥16 and ISS7 ≥8
• Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies

Who cannot take part

• Severe concomitant illness(es) that, in the Investigator's judgment, would adversely affect the patient's participation in the study
• Live vaccine except Bacille Calmette Guerin-vaccination within 28 days prior to Day 1 or plan to receive one during the trial; Bacille Calmette Guerin-vaccination within 12 months prior to Screening
• Any participant with an uncontrolled disease state as judged by the Investigator, such as asthma, psoriasis, or inflammatory bowel disease, etc. that are typically treated with oral or parenteral corticosteroids
• Previous use of a BTK inhibitor
• Had received any investigational drug (or is currently using an investigational device) within the 30 days before Day 1, or at least 5 times the respective elimination half-life time (whichever is longer)
• Previous exposure to another investigative drug for CSU
• Presence of hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb) with positive DNA test result at screening or within 3 months prior to the screening visit
• Positive hepatitis C antibody test result at screening or within 3 months prior to the screening visit
• Known or suspected immunodeficiency, or otherwise recurrent infections of abnormal frequency or prolonged duration suggesting an immune compromised status, as judged by the Investigator
• History of serious infections requiring intravenous (IV) therapy with the potential for recurrence (as judged by the Site Investigator) with less than 4 weeks interval between resolution of serious infection and first dose of study drug, or currently active moderate to severe infection at Screening (Grade 2 or higher), including active coronavirus disease 2019 (COVID-19)
• Active malignancy or history of malignancy within 5 years
• Conditions that may predispose the participant to excessive bleeding
• Positive for human immunodeficiency virus (HIV) antibody test
• Tuberculosis infection
• Any of significant laboratory abnormalities and ECG findings at the screening visit; The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial
• Clearly defined underlying etiology for CUs other than CSU (main manifestation being physical urticaria)
• Presence of skin morbidities other than CSU that may interfere with the assessment of the study outcomes
• Participants with active atopic dermatitis (AD)