Harbour BioMed Announces Positive Topline Results from Phase III Trial of Batoclimab for Treatment of Generalized Myasthenia Gravis

CAMBRIDGE,Mass.,ROTTERDAM,Netherlands and SUZHOU,China,March 6,2023 --Harbour BioMed (the "Company"; HKEX: 02142),a global biopharmaceutical company committed to the discovery,development,and commercialization of novel antibody therapeutics focusing on oncology and immunology,announces the positive topline results of its phase III clinical trial of batoclimab (HBM9161) for the treatment of generalized myasthenia gravis (gMG),which is also the first positive pivotal trial outcome for batoclimab worldwide. This marks a major milestone for Harbour BioMed as it is the Company's first product to complete phase III clinical trial and be poised for commercialization to benefit the gMG patients.

This pivotal clinical study aimed to confirm the efficacy and safety of batoclimab in patients with gMG in China. Data received from the phase III trial met primary endpoint as well as key secondary endpoints. Meanwhile,batoclimab treatment was overall safe and well-tolerated,no new safety signal was identified.

"Anti-FcRn treatment has received much attention in patients with gMG,and batoclimab is the first anti-FcRn treatment confirmed efficacious and safe in Chinese gMG population. Following the positive results of the phase II clinical study,the phase III clinical study of batoclimab by Harbour BioMed,through the joint efforts of the sponsor,investigators and patients,overcame all difficulties during the pandemic and completed enrollment of 132 subjects in 10 months,with the last subject out visit on January 14,2023",said the principal investigator Chongbo Zhao,MD,Professor of Neurology at Huashan Hospital of Fudan University in Shanghai. "The pivotal clinical success sets a monumental milestone for the development of new drugs and further reinforces the position of FcRn antagonists in the treatment of MG through high-level evidence-based medicine. It also demonstrates the strong ability of Chinese clinical investigators to independently organize high-quality clinical studies of innovative therapeutics in rare diseases."

"This breakthrough therapy represents a significant advance in the treatment of multiple pathogenic-IgG mediated autoimmune diseases,where there remains a significant unmet medical need such as gMG indication," said Dr. Jingsong Wang,Founder,Chairman and CEO of Harbour BioMed. "Despite the challenges posed by the COVID-19 pandemic,our commitment to developing life-changing therapies remained steadfast. The successful completion of this clinical trial is a testament to the clinical development capabilities and innovative dedication of our entire team,demonstrating the Company's exceptional ever-increasing business potential as well. We are excited to bring this much-needed therapy to patients,and we look forward to continuing to advance our pipeline of next-generation therapeutics to improve the lives of patients worldwide."

Batoclimab received the "Breakthrough Therapy Certificate" from NMPA in early 2021,and subsequently received positive outcome of the proof-of-concept study for the treatment of Chinese gMG patients completed in August 2021. In October 2022,the Company entered into an agreement with NBP Pharma,a wholly owned subsidiary of the CSPC Group,to co-develop batoclimab in Great China. The Company was responsible for developing and operating the full clinical trial of batoclimab for gMG in China,and will receive tiered royalties based on annual net sales of batoclimab in Greater China according to the agreement.

About Generalized Myasthenia Gravis (gMG)

Myasthenia gravis (MG) is an acquired autoimmune disease mediated by antibodies such as anti-acetylcholine receptor (AChR) immunoglobulin G (IgG) antibody and anti-muscle-specific tyrosine kinase (Anti-MuSK) IgG,which involves the postsynaptic membrane of the neuromuscular junction,causes impaired transmission at the neuromuscular junction,and presents with skeletal muscle contraction weakness. Patients often have ocular muscle manifestations,and about 85% of patients will show symptoms other than ocular muscles and develop generalized myasthenia gravis (gMG),and some patients even develop myasthenic crisis.

Current main treatments for MG include cholinesterase inhibitors and glucocorticoids and other immunosuppressive drugs,but the efficacy and safety cannot meet the clinical needs of many patients. Targeting reduction of pathogenic IgG autoantibodies is a pathophysiological mechanism driven solution in MG treatment,such as plasmapheresis and intravenous immunoglobulin,however,there still remains a significant unmet need for these treatment options,including the accessibility,safety and economic cost.

About Batoclimab (HBM9161)

Batoclimab (HBM9161),a fully human anti-FcRn mAb,blocks FcRn-IgG interactions,accelerating the degradation of autoantibodies and leads to the treatment of pathogenic IgG-mediated autoimmune diseases. Phase 2 study in myasthenia gravis showed that batoclimab can quickly and significantly alleviate patients' symptoms and improve quality of life. Earlier studies demonstrated that batoclimab is well tolerated and can rapidly reduce total IgG in a wide array of pathogenic IgG-mediated autoimmune diseases.

About Harbour BioMed

Harbour BioMed (HKEX: 02142) is a global biopharmaceutical company committed to the discovery,and commercialization of novel antibody therapeutics focusing on immunology and oncology. The Company is building its robust portfolio and differentiated pipeline through internal R&D capability,collaborations with co-discovery and co-development partners,and select acquisitions.

The Company's proprietary antibody technology platforms Harbour Mice®generates fully human monoclonal antibodies in two heavy and two light chains (H2L2) format,as well as heavy chain only (HCAb) format. Building upon the HCAb antibodies,the HCAb-based immune cell engagers (HBICE®) bispecific antibody technology is capable of delivering tumor-killing effects unachievable by traditional combination therapies. Integrating Harbour Mice®,and HBICE® with a single B cell cloning platform,our antibody discovery engine is highly unique and efficient for the development of next-generation therapeutic antibodies. For further information,please refer to www.harbourbiomed.com.

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