Phase 2 Study of Lesigercept in Adult Patients With Chronic Spontaneous Urticaria Who Are Inadequately Controlled by H1-Antihistamines

A total of 150 participants will be randomized in a 2:1 ratio to either the lesigercept or placebo group. The study will proceed with a 12-week treatment period, during which the IP will be administered every 4 weeks for a total of three doses, followed by a 4-week follow-up. In total, participants will be observed for 16 weeks to evaluate efficacy, safety, PK, PD, and immunogenicity.

Inclusion criteria

• Chronic spontaneous urticaria for ≥6 months, uncontrolled on 2nd-generation H1-antihistamines (UAS7≥16, ISS7≥8, HSS7≥8).
• Stable dose of 2nd-generation H1-antihistamines for ≥7 days; symptom diary compliance ≥80%.
• Adults 18-75 years; informed consent signed; contraception and pregnancy test requirements for both genders.
• ≥80% adherence to antihistamines during screening.

Exclusion criteria

• Any medical or lab findings suggesting risk of worsening co-existing conditions during the study.
• Clinically significant cardiovascular, neurological, psychiatric, pulmonary, renal, hepatic, endocrine, metabolic, hematologic, gastrointestinal, or immunodeficiency disorders that may compromise safety or study results.
• History of malignancy within 5 years (except certain cured skin/cervical cancers) or chronic urticaria with known etiology other than CSU (e.g., inducible urticaria, autoimmune diseases).
• Active or high-risk parasitic infections, chronic/recurrent infections (e.g., TB, HBV, HCV, HIV), or hypersensitivity/anaphylaxis to study drugs or related classes.
• Skin diseases affecting assessments (e.g., atopic dermatitis, psoriasis) or history of drug/alcohol abuse within 6 months.