FDA Grants Approval to Argenx’s Vyvgart Hytrulo for Muscle-Weakening Disease

Argenx SE announced on Tuesday that the U.S. Food and Drug Administration (FDA) has granted approval for its under-the-skin injection, Vyvgart Hytrulo, for the treatment of generalized myasthenia gravis (gMG), a genetic disease that causes muscle weakness.

Vyvgart Hytrulo is scheduled to become available in the U.S. next month, with a list price of $15,773, according to information provided by the company to Reuters.

Previously, the FDA had approved an intravenous version of the drug under the brand name Vyvgart in 2021. However, Argenx anticipates that the under-the-skin formulation will offer a more convenient dosing option compared to infusion into the veins. Vyvgart achieved global sales exceeding $400 million last year.

Vyvgart Hytrulo employs efgartigimod as its active ingredient and utilizes Halozyme Therapeutics Inc’s drug delivery system.

Generalized myasthenia gravis (gMG) is a chronic neuromuscular condition characterized by muscle weakness in various parts of the body, stemming from an abnormal immune response.

The FDA’s approval of Vyvgart Hytrulo was based on a late-stage study that demonstrated its non-inferiority to Vyvgart in reducing levels of a specific type of antibody associated with the autoimmune disease.

Vyvgart Hytrulo will now compete with AstraZeneca’s Soliris, an intravenous treatment, in the market.

This approval is expected to drive demand for Vyvgart Hytrulo as patients transition from the intravenous formulation to the subcutaneous option due to its user-friendly nature, as noted by William Blair analyst Myles Minter prior to the FDA decision.

Minter projected that Vyvgart Hytrulo could generate approximately $2.5 billion in revenue from gMG treatment alone.

By 2025, Argenx aims to target 15 autoimmune diseases that can be treated with efgartigimod.

According to a study published in the Journal of Medicine and Life in 2021, approximately 60,000 individuals in the United States are affected by myasthenia gravis, an earlier form of gMG. Argenx estimates that the target patient population for the drug will be around 17,000 individuals.