Results of a Phase III Clinical Study on Batoclimab of CSPC Published in JAMA Sub-journal

The results of a phase III clinical study on batoclimab, a human anti-FcRn monoclonal antibody jointly developed by CSPC and Harbour BioMed, were recently published online in an international medical journal JAMA Neurology (IF:29). The results demonstrated the efficacy and safety of batoclimab in the treatment of myasthenia gravis, which is of great significance for its future clinical use in the Chinese population.

About the study

This was a randomized, double-blind, placebo-controlled parallel study of 132 adult patients with generalized myasthenia gravis, jointly conducted by 27 study sites in China. Of these patients, 131 were tested positive for AChR/MuSK antibody. All the patients were randomly assigned to the batoclimab group and the placebo group, and subcutaneous injections were given in 6-week cycles. Then, they were evaluated for the sustained improvement in disease symptoms after batoclimab treatment based on the changes in the patients' Myasthenia Gravis Activities of Daily Living (MG-ADL) scale scores from baseline.

According to the study data, the curve of improvement rate in MG-ADL score in the batoclimab group was significantly separated from that in the control group at 2 weeks after treatment, suggesting that batoclimab could take effect quickly and relieve symptoms. At day 43 (i.e. the end of the first treatment cycle), the continuous ADL score improvement rate (the proportion of patients with ADL score improved by 3 points from baseline for 4 consecutive weeks) in the batoclimab group was up to 58.2% (vs. 31.1% in the control group), suggesting that batoclimab could significantly improve patients' symptoms, with the therapeutic effect sustainable. During the first treatment cycle, 25.4% of patients in the batoclimab group achieved minimal symptom expression (MSE, defined as an ADL score of 0 or 1), much higher than 4.7% in the control group.

The batoclimab group also showed a similar trend compared with the control group regarding MG quantitative score, MG composite score, and 15-item MG-ADL score analysis, which further suggested the efficacy reliability of batoclimab. During treatment, the incidence of treatment-emergent adverse events (TEAEs) of the batoclimab group was similar to the control group, with good overall tolerability and safety data.

Professor Zhao Chongbo, principal investigator of the batoclimab clinical trial and chief physician of the Department of Neurology, Huashan Hospital, Fudan University, said that the results of this high-quality study could provide data from the Chinese population for the treatment of myasthenia gravis with FcRn antagonists, and further confirmed the robust efficacy and safety of this class of drugs, which was of great significance.

About myasthenia gravis

Myasthenia gravis is a chronic autoimmune neuromuscular disorder characterized by skeletal muscle weakness. Studies have shown that antibodies such as anti-acetylcholine receptor (AChR) immunoglobulin G (IgG) and anti-muscle-specific tyrosine kinase (MuSK) IgG play an important role in the occurrence and development of myasthenia gravis. These pathogenic IgG antibodies will interfere with the aggregation and functioning of neurotransmitters, as well as neuromuscular junction signaling. The failure in nerve signaling makes simple actions in daily life difficult, severely affecting patients' quality of life. The neonatal Fc receptor (FcRn) is a cellular receptor that can bind IgG and play a key role in preventing the degradation of IgG antibodies, including pathogenic IgG antibodies.

About batoclimab

Batoclimab (HBM9161), a human anti-FcRn monoclonal antibody, can block FcRn-IgG binding and accelerate the clearance of IgG (including pathogenic IgG) in vivo. It is expected to lead to a new generation of therapies for pathogenic IgG-specific antibody-mediated autoimmune diseases, including myasthenia gravis.

In October 2022, NBP Pharmaceutical, a wholly-owned subsidiary of CSPC, entered into a licensing agreement with Harbour BioMed to obtain the rights to develop, manufacture, and commercialize batoclimab (HBM9161) in Greater China. Based on the mechanism of action of batoclimab and the existing clinical data, CSPC plans to continue its development in other indications of autoimmunity.

The information is only a reference for medical professionals, not a basis for product recommendations.