argenx (ARGX) said a phase 3 study evaluating its experimental drug, Vyvgart Hytrulo, in adults with autoimmune myositis met main goal.

The company said the patients treated with the drug showed a statistically significant improvement in mean total improvement score at week 52 compared with placebo.

Treatment benefits emerged as early as week 4 and were sustained through the 52-week treatment period, including during steroid tapering, the company said.

argenx said the primary endpoint was also met in patients with immune-mediated necrotizing myopathy, while dermatomyositis patients showed a similar improvement, although it did not reach statistical significance.