Harbour BioMed (the "Company"; HKEX: 02142), a global biopharmaceutical company committed to the discovery and development of novel antibody therapeutics in immunology, oncology and other areas,  announced that the National Medical Products Administration (NMPA) of China has approved the Biologics License Application (BLA) for batoclimab injection (subcutaneous injection) (batoclimab SC), 170 mg (1 mL)/vial, for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive.

The approval is supported by positive results from a pivotal Phase 3 clinical study conducted at 27 centers in China. The main study population was patients with generalized myasthenia gravis who were positive for acetylcholine receptor antibodies (AChR-Ab) or muscle-specific tyrosine kinase antibodies (MuSK-Ab). The primary endpoint of the study was the proportion of the population with sustained improvement in the Myasthenia Gravis Activities of Daily Living Scale (MG-ADL) score during the first cycle of treatment. Sustained improvement was defined as a reduction in MG-ADL score of ≥ 3 points from baseline that persisted for at least 4 weeks. 58.2% of patients treated with batoclimab SC achieved the primary endpoint, which was significantly higher compared with 31.3% in the placebo group (P=0.001). Treatment effect was observed as early as the second week of therapy.

Additionally, batoclimab SC group demonstrated significant improvements in secondary endpoints compared with placebo group, including sustained Quantitative Myasthenia Gravis (QMG) improvement (64.2% vs 40.6%; P=0.008), duration of 3-point or greater MG-ADL improvement (51.5% vs 36.1%; P=0.008); proportion of people with clinical expression of minimal symptoms (defined as having a MG-ADL score of 0 or 1) at any visit (25.4% vs 4.7%; P=0.004), and sustained MG-ADL improvement in the second treatment cycle (62.7% vs 36.4%; P=0.002).

Batoclimab SC was generally well tolerated. The most frequently reported adverse event in the treatment group is peripheral edema (38.8% vs 4.6% for placebo), all of which were mild to moderate in severity. Plasma albumin levels decreased during treatment but returned spontaneously upon treatment discontinuation.

"The approval of batoclimab SC is a proud moment for everyone at Harbour BioMed," Dr. Jingsong Wang, Founder, Chairman and Chief Executive Officer of Harbour BioMed, commented. "We believe that, with its unique mechanism of action, batoclimab SC has the potential to provide a new treatment option for patients with gMG. We are deeply grateful to the patients, investigators, and our partner for their trust and collaboration throughout this journey, and we look forward to making this therapy available to patients as quickly as possible, so that more people in need can benefit from it."

"Batoclimab SC is the first FcRn-targeted therapy to complete its entire clinical development in China," Professor Chongbo Zhao, MD, Principal Investigator of the pivotal Phase 3 study and Professor of Neurology at Huashan Hospital of Fudan University, commented. "The trial results showed rapid onset of action, deep symptom improvement, and a favorable safety profile. This high-level evidence, based on data from Chinese patients, indicates that batoclimab SC provides a new treatment option for myasthenia gravis. This approval represents a monumental milestone in this field, and we believe it will bring a highly valuable new treatment option to physicians and patients in China."

Pursuant to the license agreement entered into between Harbour BioMed and NBP Pharma on October, 2022, commercialization of batoclimab in the Greater China region (Mainland China, Hong Kong, Macau, and Taiwan) will be conducted by NBP Pharma, a subsidiary of CSPC Pharmaceutical Group. Harbour BioMed will receive tiered royalties based on annual net sales of batoclimab in Greater China.