Sailxin Bio's Treg Cell Therapy IND for Spinal Bulbar Muscular Atrophy Accepted by NMPA

On December 1, 2025, Shanghai Saierxin Biomedical Technology Co., Ltd. (hereinafter referred to as "NOVABIOTX") achieved a new milestone in the NP001 project, with its IND for Spinal and Bulbar Muscular Atrophy (SBMA, also known as Kennedy's disease) accepted by the NMPA.

At the same time, the company has submitted an IIT for SBMA to Union Hospital, Tongji Medical College, Huazhong University of Science and Technology (The ethical application for the investigator-initiated clinical trial is scheduled to officially launch in February 2026, marking another critical step for this therapy moving from preclinical research to the clinical stage.

Spinal Bulbar Muscular Atrophy (SBMA), commonly known as Kennedy's Disease, is an X-linked recessive neurodegenerative disorder caused by the abnormal expansion of a CAG repeat sequence in exon 1 of the androgen receptor gene, and it belongs to the family of polyglutamine diseases. The disease was included in China's "First List of Rare Diseases" (Item No. 109) in 2018.

The Therapeutic Potential of Treg Cells in SBMA Treatment

Neuroinflammation plays a crucial role in the pathogenesis of SBMA. Studies have shown that abnormal activation of microglia and astrocytes often occurs in patients, accompanied by elevated levels of pro-inflammatory factors such as IL-6 and TNF-α, which further exacerbates motor neuron damage.

Against this backdrop, regulatory T cells (Treg) demonstrate multifaceted therapeutic potential by modulating immune responses and tissue repair through various pathways:

◽ In terms of immune regulation, Treg promotes the transformation of macrophages from the pro-inflammatory M1 type to the reparative M2 type by secreting anti-inflammatory factors such as IL-10 and TGF-β, thereby suppressing excessive inflammatory responses. Meanwhile, Treg regulates dendritic cell function and limits effector T cell activation by expressing inhibitory receptors like CTLA-4 and LAG-3. Additionally, Treg can comprehensively suppress abnormal immune responses by producing immunosuppressive adenosine and inducing apoptosis in inflammatory cells.

◽ In terms of muscle tissue repair, Treg cells are recruited to the injury site via the IL-33/ST2 signaling axis. They then promote the polarization of macrophages from M1 to M2 type by secreting factors such as IL-4, IL-10, and IL-13, thereby inhibiting the fibrosis process. Notably, amphiregulin (AREG) secreted by Treg can directly activate muscle stem cells through the EGFR pathway, promoting their proliferation and differentiation, and enhancing tissue regeneration capacity.

◽ In different types of muscle injuries, the mechanism of Treg action varies. In acute injuries, their aggregation depends on the IL-33/ST2 signaling pathway; whereas in chronic conditions such as the Duchenne muscular dystrophy model, Tregs reduce inflammation and fibrosis by suppressing M1 macrophage activation and IFN-γ responses. Studies have shown that increasing Treg levels via IL-2/anti-IL-2 complexes can significantly enhance muscle regeneration, providing a theoretical basis for clinical applications.

Mechanism of Treg in Muscle Tissue Repair

Based on the aforementioned mechanism, the NP001 cell injection developed by NOVABIOTX aims to utilize Treg therapy comprehensively.Regulate neuroinflammation, delay disease progression, promote skeletal muscle repair, and limit muscle fibrosis.. This strategy not only opens up a new avenue for the treatment of SBMA but also provides a new perspective for cell therapy in other neurodegenerative diseases.