POC Study to Evaluate BSI-045B in Moderate-to-severe Atopic Dermatitis

This study is a Phase 2a, proof-of-concept clinical study designed to evaluate the efficacy, safety, tolerability, PK, immunogenicity, and PD of BSI-045B injection in patients with moderate to severe AD. The study will be unblinded. Following a loading dose of BSI-045B (300 mg) SC QW for 4 weeks, patients will move to maintanence 300 mg SC Q2W through Week 24. There will be a 12-week Follow-up Period after treatment. A Safety Steering Committee (SSC) will monitor the study to identify questions concerning safety. The primary efficacy endpoint is the proportion of patients with ≥EASI75 at Week 26 (2 weeks after last dose at Week 24), compared with baseline (Day1). Additional efficacy outcomes also include other scores on EASI, Investigator's Global Assessment (IGA), Facial IGA, and Peak Pruritus Numerical Rating Scale (PP-NRS). Efficacy assessments will be conducted at Screening, within the first hour prior to dosing on Day 1, at all subsequent visits, and at the time of early withdrawal from the study.