- The Food and Drug Administration on Tuesday approved a version of Argenx’s rare disease drug Vyvgart that can be injected under the skin, adding a more convenient option than the infused formulation that’s been available to date.
- Like the infused form of Vyvgart, the new subcutaneous type is cleared for use in adults with a condition called generalized myasthenia gravis who also have a harmful antibody known as AChR. While the subcutaneous shot can be done more quickly, it still must be administered by a healthcare professional, either at home or in a medical office.
- Argenx said it will sell this new version, which combines Vyvgart’s main drug ingredient with an enzyme that aids under-the-skin injections, “at parity” to Vyvgart’s price on a net annual revenue basis. The drug is expected to be available in July.
Argenx has impressed Wall Street with its launch of Vyvgart, which again outpaced analyst sales forecasts during the first quarter. While the approval of the subcutaneous formulation was expected, it could still help spur further uptake.
“Overall, we believe the approval of Vyvgart Hytrulo should further bolster the strong launch momentum in [myasthenia gravis], providing an alternative to weekly IV administration and helping expand Vyvgart use into earlier lines of treatment,” Thomas Smith, an analyst at SVB Securities, wrote in a note to clients, using the subcutaneous formulation’s brand name.
However, the FDA did not approve Vyvgart Hytrulo in myasthenia gravis patients who are negative for AChR antibodies, or authorize self-administration — broader labeling that Argenx has sought.
Vyvgart is designed to reduce circulating antibodies known as IgG that, in people with myasthenia gravis, go haywire, disrupting communication between nerves and muscle in a way that causes serious muscle weakness. Most people diagnosed with myasthenia gravis progress to the generalized form of the condition within two years, according to Argenx.
The infused formulation is administered once weekly over a one hour session. By comparison, the subcutaneous shot can be given by a healthcare professional in 30 to 90 seconds.
Along with Vyvgart’s launch in myasthenia gravis, analysts are awaiting results from studies testing the drug in chronic inflammatory demyelinating polyneuropathy, or CIDP, primary immune thrombocytopenia and pemphigus vulgaris. Results in CIDP are expected in July, while data from tests in the latter two diseases are anticipated during the fourth quarter.
Argenx’s success with Vyvgart has made it one of a handful of biotechs flagged by analysts as a potential takeover target by large pharmaceutical companies. A deal would be expensive, however. Steady share price growth since 2020 has swelled Argenx’s market capitalization to above $21 billion.