As argenx continues to rise to profitability based on the strength of its indication-spanning FcRn inhibitor Vyvgart, a simpler route of administration for the med forms a key piece of the Dutch immunology specialist’s expansion plans.
Heading into 2025, the chief item on argenx’s agenda is the FDA’s April 10 target action date to decide on the approval of a prefilled syringe version of Vyvgart—also known as efgartigimod—in its current generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP) indications.
If argenx gets the label it’s hoping for, the new green light could clear patients to administer Vyvgart themselves, akin to existing approvals for the drug’s subcutaneous presentation in Europe and Japan. In the U.S., the drug's infusion and subcutaneous injection formulations typically require patients to travel to a doctor's office or an infusion center for treatment, followed by 30 minutes of monitoring for allergic reactions.
The goal with the planned launch of the prefilled syringe—which would mark the next phase in the drug’s evolution from infusion to below-the-skin injection—is to move Vyvgart into earlier lines of therapy in gMG and build on the current momentum of the CIDP launch, which kicked off last year, the company’s chief operating officer, Karen Massey, said in a recent interview.
When Vyvgart first launched in gMG in early 2022, much of the drug’s use was in refractory patients, the tough-to-treat subset in which biologics have historically been prevalent, Massey explained. Since then, argenx feels confident that Vyvgart has raised the bar in terms of both safety and efficacy in MG, in turn helping push the biologic earlier into the treatment sequence.
“We’re seeing over 60% of the patients starting on Vyvgart now are coming directly from the orals, from corticosteroids or from Mestinon,” Massey said, referring to the long-approved MG drug pyridostigmine by its brand name. “And that’s good for patients, because it means they’re getting access to Vyvgart earlier.”
The convenience of a prefilled syringe could further extend Vyvgart's reach by attracting new prescribers, Massey figures. The company previously witnessed this dynamic when it introduced the drug's subcutaneous presentation, Vyvgart Hytrulo.
Anticipating an approval for the new format, argenx is currently prepping for the Vyvgart prefilled syringe launch by hashing out payer policies, upping engagement with doctors and reaching out to patients, Massey noted.
Argenx also plans to continue its doctor education and engagement efforts to help grow its prescriber base for Vyvgart, which currently sits at around 3,500 neurologists, Massey said.
With regard to patient awareness, argenx recently unveiled a new direct-to-consumer TV ad for Vyvgart Hytrulo in CIDP dubbed “Live Vyvidly.” The new spot covers Vygart’s subcutaneous presentation specifically rather than the anticipated prefilled syringe.
“Activating the patient is always important,” Massey stressed. “They’re an important advocate for health, and, in this case, it’s important that they give some thought to and have some agency and some choice over the routes of administration that makes sense for them in their day-to-day life.”
On Vyvgart’s launch in CIDP, the drug has now reached more than 1,000 patients, according to argenx’s COO. Roughly 85% of those CIDP patients have switched over to Vyvgart from intravenous immunoglobulin treatment, in line with argenx’s expectations prior to the launch, Massey pointed out.
All told, argenx has reported preliminary product sales of $2.2 billion for 2024, with $737 million of that coming in the fourth quarter alone. Argenx has yet to reveal sales guidance for 2025, though it does expect to become profitable this year while incurring marketing, administrative and R&D expenses of around $2.5 billion.
Aside from Vyvgart’s new launch and the growing popularity of the drug’s subcutaneous delivery format, Massey attributed argenx’s growth trajectory to what she called “the halo effect from CIDP to MG.”
With the spotlight on Vyvgart Hytrulo from the CIDP launch, neurologists prescribing treatments for both diseases are becoming enticed by the convenience of the med’s subcutaneous format and are increasingly considering whether to switch their gMG patients over to argenx’s drug, Massey explained.
The commercial growth and continued development of Vyvgart, plus work on other key immunology assets like empasiprubart and the MuSK-targeting antibody ARGX-119, all form part of argenx’s aim to treat 50,000 patients, secure 10 approved indications and advance five pipeline candidates into late-stage development by the end of the decade.
The company plans to release complete 2024 financial results later this month.