Chinese regulators to review batoclimab’s approval request for gMG
Therapy is being tested in global Phase 3 Flex study in US, Canada, Europe, and Asia
The National Medical Products Administration (NMPA) of China has agreed to consider approving batoclimab (HBM9161) for treating generalized myasthenia gravis (gMG).
Submitted as a biologics license application (BLA), the request is supported by positive top-line data from a Phase 3 clinical trial (NCT05039190) from China. The trial met its primary and secondary goals and showed batoclimab eased gMG symptoms and their impact on daily activities.
“We are delighted that batoclimab has become our first BLA successfully accepted by the NMPA demonstrating our strong R&D capability,” Jingsong Wang, MD, PhD, founder, chairman, and CEO of Harbour BioMed, the therapy’s developer, said in a company press release. “We are excited to bring this much needed drug to patients, and will continue to advance our innovative pipeline of next-generation therapeutics to fulfill the unmet medical needs.”
The therapy is also being evaluated in the global Phase 3 Flex Study (NCT05403541), which is enrolling patients in the U.S., Canada, Italy, Poland, Romania, Georgia, Japan, and South Korea.
The trial, sponsored by Immunovant, which is developing batoclimab in the U.S. and Canada, expects to enroll about 210 adults with mild to severe gMG. Top-line data are anticipated in 2024.
Batoclimab lowers levels of disease-causing antibodies
A feature of gMG is the presence of self-reactive antibodies that disrupt the communication between nerve and muscle cells, resulting in fatigue and muscle weakness.
Batoclimab is made to block the FcRn protein receptor, which normally prevents antibodies in the bloodstream from being destroyed. As a result, disease-causing antibodies are more readily broken down. By lowering their number, batoclimab is expected to ease disease severity.
“Anti-FcRn treatment is at the center of focus in gMG disease area,” said Chongbo Zhao, MD, the study’s lead investigator. “Batoclimab is the first anti-FcRn treatment completed clinical development with positive results and confirmed efficacious and safe in Chinese gMG population. We believe that this innovative therapy will set a new benchmark for the treatment of gMG, significantly improve drug availability and benefit more patients.”
A now complete, Harbour BioMed-sponsored Phase 2 clinical trial (NCT04346888) showed batoclimab rapidly lowered the levels of disease-causing antibodies and eased symptoms in 30 adults with moderate to severe gMG.
Top-line data from the Phase 3 Chinese study came from 132 gMG adults who were randomly assigned to receive two treatment cycles of batoclimab (680 mg) or a placebo.
The study met its main goal, with a significant proportion of participants achieving a sustained reduction in three or more points in the MG Activities of Daily Living (MG-ADL), a patient-reported measure of disease severity. Similar findings were observed in the Quantitative MG (QMG) score, a clinician-rated disease severity measure.
“The clinical studies of batoclimab, spanning the pandemic, are the result of joint efforts of investigators and patients with Harbour BioMed,” Wang said. “Its success sets a monumental milestone for the development of innovative therapeutics in the treatment of gMG.”
The findings were consistent with data from Immunovant’s Phase 2a ASCEND MG study (NCT03863080), which showed batoclimab significantly eased symptoms and lowered antibody levels in 15 adults with moderate to severe gMG.
The new global Phase 3 Flex Study will evaluate changes in the MG-ADL scale as its primary outcome measure. Higher rescue doses to treat flare-ups and lower dosing for maintenance treatment will be explored too.