Already on a roll with its first-in-class FcRn blocker Vyvgart, argenx has reported successful trial results that could pave the way for the fast-rising blockbuster to reach a new indication—ocular myasthenia gravis.
The phase 3 Adapt Oculus study, which is the first to specifically evaluate a targeted treatment for ocular myasthenia gravis (oMG), has achieved its primary endpoint, demonstrating that Vyvgart can improve vision by a statistically significant margin, argenx reported Thursday.
The company hailed the victory the same day it unveiled its 2025 earnings, showing that Vyvgart sales came in at $1.3 billion in the fourth quarter and $4.2 billion for the full year.
A year ago, argenx posted fourth-quarter 2024 sales of $737 million and full-year sales of $2.2 billion. The 90% annual revenue boost allowed the Dutch drugmaker to turn an operating profit for the first time, at $1.05 billion for the year.
As for the success in the oMG study, it comes after argenx sustained a rare defeat with Vyvgart, coming up short in a trial for thyroid eye disease (TED) two months ago. The loss convinced argenx to scrap the development of Vyvgart in the indication.
The oMG trial included 141 patients from the U.S., Europe and Asia with a mild (Class 1) form of the disorder who received four weekly subcutaneous injections of Vyvgart or placebo, followed by a 4-week follow-up. Using patient-reported outcomes on the Myasthenia Impairment Index (MGII), those in the Vyvgart arm had a mean 4.04-point change versus a mean change of 1.99 in the placebo arm.
Patients treated with Vyvgart also saw a reduction of key ocular symptoms—diplopia (double vision) and ptosis (drooping of the upper eyelids).
“There is a long-standing gap for a patient population that has historically been excluded from clinical trials,” Luc Truyen, M.D., Ph.D., argenx’s chief medical officer, said in the company’s quarterly conference call. “Patients are still relying on chronic steroids and symptomatic therapy, which causes an unacceptable treatment burden over time. For the first time, we are bringing forward a therapy that specifically addresses the underlying pathological mechanism of ocular MG.”
The company will provide full results at a future medical conference, and argenx will file an application for FDA approval.
A month ago, argenx announced that the FDA had accepted its application to expand Vyvgart to those with acetylcholine receptor antibody (AChR-Ab) seronegative generalized myasthenia gravis (gMG), for which the U.S. regulator has assigned a decision date of May 10.
With the potential label expansions, argenx is on track to reach an additional 18,000 patients, including 7,000 in oMG, chief commercialization officer Sandrine Piret-Gerard said during the call.
oMG is a chronic autoimmune disease causing weakness in eye muscles. It is caused by antibodies blocking acetylcholine receptors at the neuromuscular junction, affecting only eye muscles or progressing to general weakness.
“Ocular myasthenia gravis significantly impacts patients’ daily lives, affecting vision, independence and the ability to do routine tasks, such as work or drive a car. Yet today, there are no approved targeted medicines for this disease,” Carolina Barnett-Tapia, M.D., Ph.D., of the University of Toronto, said in a release.
The FDA originally approved Vyvgart in December 2021 for the treatment of generalized myasthenia gravis (gMG). A year later, the agency signed off on Vyvgart Hytrulo, a subcutaneous formulation, which provided more convenience for patients. In 2024, an approval for Vyvgart Hytrulo came for the rare immune-mediated neuromuscular disorder chronic inflammatory demyelinating polyneuropathy.