- Argenx on Tuesday said a more convenient formulation of its approved drug Vyvgart reduced signs of disease in patients with myasthenia gravis as well as Vyvgart does, reporting data from a trial it plans on using to support an application to the Food and Drug Administration this year.
- Vyvgart is given to patients intravenously, similar to competing drug Soliris from AstraZeneca and to immunoglobulin therapy. The new Argenx shot, which has now succeeded in a Phase 3 trial, is administered subcutaneously, which means patients can take it at home without the help of medical practitioners.
- Several investment banks, including Bernstein, have recently named Argenx as a potential acquisition target based on expected product sales. An approval of a subcutaneous formulation and expansion of Vyvgart into other autoimmune diseases could further spur buyers' interest.
The FDA approved Vyvgart at the end of 2021 for generalized myasthenia gravis, which can cause weakness throughout the body, setting an annual list price of about $225,000 for a typical patient. People with myasthenia gravis have malfunctioning antibodies that attack muscle cells where they receive signals from the nervous system, impairing muscle function. Vyvgart prevents those antibodies from binding with the muscle cells.
As Argenx launched Vyvgart in early January, the biotech has yet to report any sales. However, Bernstein analyst Ronny Gal forecast $2.2 billion in sales by 2025, potentially making it attractive to bigger drugmakers seeking to grow revenue as their older products lose patent protection.
The new data for the subcutaneous formulation of Vyvgart could help support that case. The Phase 3 study was designed as a "bridging" test to evaluate whether the new shot, which relies on delivery technology from Halozyme that several other drugmakers use, has the same effect as intravenous Vyvgart.
The study, which enrolled 110 people, met its primary goal of "non-inferiority," with the subcutaneous shot reducing antibodies by 66% after 29 days of treatment. Vyvgart, by comparison, led to a reduction of 62%, the company said. Around two-thirds of patients receiving the subcutaneous shot were classified as responders using two measures of function and symptoms, according to Argenx.
Safety data looked similar, although 21 patients given the new shot reported injection site reactions, compared with only one who got the intravenous formulation. Two subcutaneous patients discontinued treatment because of adverse events, while none did in the intravenous group.
Danielle Brill, an analyst at Raymond James, also noted in a March 22 note to clients that 11% of subcutaneous patients experienced worsening disease symptoms, compared with 2% of intravenous patients. However, Brill said the symptoms became worse at the end of the longer-term observation period, when no redosing was allowed according to the trial design.
Argenx shares rose about 4% Tuesday morning following the announcement of the trial results. The company has a market valuation of more than $15 billion.