argenx SE announced that the U.S. Food and Drug Administration (FDA) has extended the review of the Biologics License Application (BLA) for subcutaneous (SC) efgartigimod (1000mg efgartigimod-PH20) for the treatment of adult patients with generalized myasthenia gravis (gMG) to June 20, 2023. The FDA notified argenx on January 26, 2023 that information submitted in connection with the ongoing review of the SC efgartigimod BLA constituted a major amendment and requires an extension to allow sufficient time to review. No additional data or studies have been requested at this time.