Zai Lab Plans to Seek Efgartigimod Approval in China in Early 2022
Zai Lab is planning — in the first half of 2022 — to ask Chinese authorities to approve efgartigimod (ARGX-113) as a treatment for generalized myasthenia gravis (gMG) in that country.
The therapy, being developed by Argenx and designed to lessen the body’s immune attacks against its own healthy tissues, currently is under review in the U.S., the EU, and Japan. Earlier this year, Argenx and Zai Lab struck a deal under which Zai will be responsible for the development and future commercialization of efgartigimod in Greater China, including the mainland, Hong Kong, Taiwan, and Macau.
In a recent meeting between Zai and China’s National Medical Products Administration (NMPA), discussions indicated “the potential for an accelerated pathway” for the approval of efgartigimod as a treatment for gMG, the company said in a press release detailing its third-quarter updates.
Efgartigimod is an investigational antibody fragment that is designed to block the activity of a protein called neonatal Fc receptor. This protein normally helps prevent the destruction of certain antibodies circulating in the bloodstream. By blocking its activity, efgartigimod is expected to increase the rate at which antibodies are destroyed — including the self-targeting antibodies that drive MG.
Argenx sponsored a Phase 3 trial called ADAPT (NCT03669588) to test the therapy’s safety and efficacy. The trial enrolled 167 adults with gMG, who were randomly assigned to receive either efgartigimod (10 mg/kg) or a placebo. Treatments were given in cycles of four hour-long infusions over the course of four weeks, with a maximum of three treatment rounds over the course of the trial, which lasted 26 weeks (about six months).
Results from ADAPT demonstrated that efgartigimod eased gMG symptoms, regardless of the presence of anti-AChR antibodies — the most common type of MG-driving antibodies.
More recent analyses from the trial showed that, compared with those given a placebo, efgartigimod-treated patients were significantly more likely to have minimal disease symptoms and to see improvements in muscle strength.
Supported by these data, Argenx is now seeking approval of efgartigimod for gMG in the U.S. and Europe. A decision in the U.S. is expected before the end of the year, according to Zai.
“Subject to United States Food and Drug Administration (FDA) approval and further discussion with the NMPA, we expect to file the New Drug Application (NDA) in China by the first half of 2022,” the company said.
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