A phase 3 study of AstraZeneca’s gefurulimab has hit its primary and all secondary endpoints, teeing up talks with regulators about the potential blockbuster generalized myasthenia gravis (gMG) treatment.
AstraZeneca listed gefurulimab among candidates it expects to generate sales of between $1 billion and $3 billion at its investor day last year. The forecast rests on the belief that the weekly, self-administered subcutaneous nanobody C5 inhibitor can unlock an earlier, broader population than AstraZeneca’s existing gMG drug Ultomiris, which is given as a one-hour infusion and is feeling the pressure in a competitive market.
The phase 3 trial randomized 260 people with anti-acetylcholine receptor antibody-positive gMG to take gefurulimab or placebo. After 26 weeks, people on gefurulimab performed significantly better on a gMG scale that assesses the ability to perform daily activities, achieving the primary endpoint of the study.
Marc Dunoyer, chief of AstraZeneca’s rare disease unit, said in a statement that the data “reinforce the established safety profile and efficacy of C5 inhibition and show the potential for gefurulimab as a first-line biologic, with the convenience of a self-administered option.”
The trial’s secondary endpoints assessed how people performed on other gMG scales and evaluated the proportion of patients who were classed as responders. AstraZeneca is yet to share any data, saying only that the trial met all its endpoints, gefurulimab was well tolerated and no new safety signals were seen.
AstraZeneca is planning to present the data at a medical meeting and to share the results with regulators. The company has identified gefurulimab as a product that can drive growth through 2030 and beyond by opening up more of the market. AstraZeneca sells Ultomiris in gMG, but it is used by more advanced patients. Competitive pressure in gMG offset growth of Ultomiris in other indications in the first quarter.
“Ultomiris has a key position in this market, but, obviously, other mechanisms have an attraction for people who are switching from the steroids or immunosuppressant as a first-line treatment. Ultomiris is also competing in that segment, but it’s not the only mechanism available,” Dunoyer said in April.
The gMG market has grown in recent years as FcRn inhibitors have won approval. Led by argenx’s Vyvgart Hytrulo, the drug class has given gMG patients self-administered subcutaneous treatment options.