Argenx (ARGX) said Friday that Japan's Ministry of Health, Labour and Welfare approved its Vyvdura injection as a treatment for adult patients with chronic inflammatory demyelinating polyneuropathy, a progressive and debilitating neuromuscular disorder of the peripheral nervous system.

The approval is based on the results of a study, which showed that 69% of patients treated with the drug demonstrated clinical improvements, including in mobility, function and strength.

The Japanese regulator approved Vyvdura for manufacturing and marketing in January. The drug was launched in April for the treatment of generalized myasthenia gravis.