When Argenx’s Vyvgart won FDA approval in December for generalized myasthenia gravis (gMG), the entrant presented an attractive alternative to AstraZeneca’s entrenched rare-disease blockbuster Soliris.
But AZ may soon have another option for doctors to consider in treating gMG, a rare, chronic, debilitating autoimmune neuromuscular disease that causes severe weakness and a loss of muscle function.
AZ’s follow-on treatment for Soliris, Ultomiris, which has already achieved blockbuster status as a treatment for paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (AHUS), is lined up for a potential approval this year in gMG. Tuesday at the American Academy of Neurology (AAN) annual meeting, AZ presented follow-up results from a phase 3 trial that enhance Ultomiris’ case in the disease.
The open-label extension of the Champion-MG study shows long-term efficacy in those with anti-acetylcholine receptor (AChR) antibody-positive gMG, with improvements in daily activities, muscle strength and quality of life which sustained for more than a year.
“These results reinforce that C5 inhibition with predictable dosing is an important treatment option which provides sustained improvement of functional activities,” lead investigator James Howard, on the University of North Carolina School of Medicine, said in a release.
While Soliris and Ultomiris are C5 inhibitors, Vyvgart is a neonatal Fc receptor blocker, setting the companies up for a battle to show which mechanism is superior to treat gMG.
A Spherex survey of U.S. neurologists from February showed that 51% perceived Vyvgart to “offer a substantial advance over other currently available therapies.”
Vyvgart has another advantage. While it costs around $225,000 annually—through value-based arrangements with payers—Soliris knocks in at $470,000 per year.
AZ obtained Soliris and Ultomiris through its $39 billion buyout of Alexion, which was first revealed in December of 2020. Soliris generated $1.8 billion in sales last year.