November 10, 2026 — Simcere Pharmaceutical Group (02096.HK) announced today that SIM0725, its proprietary long-acting antagonist monoclonal antibody targeting the interleukin-2 receptor β chain (CD122), has received approval from China's National Medical Products Administration (NMPA) to initiate clinical trials for the potential treatment of autoimmune diseases.
SIM0725 was developed using Simcere's proprietary long-acting protein engineering platform. As a long-acting CD122 antagonist, SIM0725 blocks interleukin-2 (IL-2) and interleukin-15 (IL-15)-mediated signaling, thereby inhibiting relevant effector and memory T-cell responses. It is also expected to disrupt the survival and maintenance of IL-15-dependent pathogenic tissue-resident memory T cells (TRMs), potentially modulating autoimmune responses associated with disease persistence and relapse.
Preclinical studies have demonstrated that SIM0725 exhibits greater pharmacological activity than the comparator molecules tested in humanized mouse efficacy models, while having minimal impact on the abundance and proliferation of regulatory T cells (Tregs), suggesting its potential for differentiated immunomodulation. In addition, SIM0725 has demonstrated a long-acting pharmacokinetic/pharmacodynamic (PK/PD) profile in cynomolgus monkeys, supporting the potential for less frequent dosing in clinical settings.
Based on its mechanism of action and preclinical evidence, SIM0725 has the potential to address multiple autoimmune diseases, including vitiligo, alopecia areata, celiac disease, and eosinophilic esophagitis (EoE). With its potential applicability across multiple indications, SIM0725 could become a "pipeline-in-a-product" candidate, offering the possibility of addressing a range of autoimmune diseases with a single molecule.