Core Insights - Orelabrutinib is the first BTK inhibitor to show significant clinical activity in a Phase 2 clinical trial for Systemic Lupus Erythematosus (SLE) [1] - Zenas BioPharma has acquired exclusive rights to develop, manufacture, and commercialize orelabrutinib for Multiple Sclerosis (MS) globally, and for non-oncology fields outside Greater China and Southeast Asia [1][5] Clinical Trial Results - In the Phase 2b study, 187 patients were randomized into three groups: orelabrutinib 75 mg once-daily, orelabrutinib 50 mg once-daily, and placebo [2] - The primary endpoint, SLE Response Index-4 (SRI-4) response rate at week 48, was met with the 75 mg group showing a response rate of 57.1% compared to 34.4% for placebo (p < 0.05) [2] - Secondary endpoints, including SRI-6 and British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response rates, were also significantly higher in the 75 mg group compared to placebo (p < 0.05) [3] Safety and Tolerability - Orelabrutinib was well tolerated, exhibiting a safety profile consistent with BTK inhibition and the disease biology of SLE [3] Development Pipeline - Zenas is advancing orelabrutinib into a Phase 3 trial for Primary Progressive MS (PPMS) and plans to initiate a Phase 3 trial for Secondary Progressive MS (SPMS) in Q1 2026 [6] - Orelabrutinib is already approved for B cell malignancies in mainland China and Singapore, marketed by InnoCare [6] Company Overview - Zenas BioPharma is a clinical-stage global biopharmaceutical company focused on developing transformative therapies for autoimmune diseases [7] - The company is advancing two late-stage molecules: obexelimab and orelabrutinib, with obexelimab being a bifunctional monoclonal antibody targeting CD19 and FcγRIIb [7][8]