Alexion Pharmaceuticals, a subsidiary of AstraZeneca, has received the US Food and Drug Administration (FDA) approval for Ultomiris (ravulizumab-cwvz) to treat a type of generalised myasthenia gravis (gMG) in adults.

Ultomiris is a long-acting C5 complement inhibitor that provides immediate, complete and sustained complement inhibition.

The drug was indicated for adults with gMG, who are anti-acetylcholine receptor (AChR) antibody-positive, which represents 80% of people living with gMG.

gMG is a rare, chronic, autoimmune neuromuscular disorder where patients lose muscle function and suffer from severe muscle weakness.

With the FDA approval, Ultomiris becomes the first and only long-acting C5 complement inhibitor approved in the US for the treatment of gMG.

Alexion chief executive officer Marc Dunoyer said: “Since bringing forward the first complement inhibitor, we’ve continued to listen to the community and focused innovation on the needs of gMG patients.

“We’re proud to deliver on this commitment with today’s approval. Ultomiris, the only long-acting C5 inhibitor, will benefit a broader range of patients, including those with milder symptoms.

“As presented at the 2022 American Academy of Neurology Annual Meeting, Ultomiris has demonstrated clinical benefit through 60 weeks, with treatment every eight weeks, compared to Soliris every two weeks.”

The FDA approval was supported by positive results from the Phase 3 CHAMPION-MG trial that enrolled 175 patients across North America, Europe, Asia-Pacific and Japan.

The change in the MG-ADL total score from baseline at Week 26 was the primary endpoint of the study, and improvement in disease-related and quality-of-life measures include the secondary endpoints.

In the study, Ultomiris showed improvement in the Myasthenia Gravis-Activities of Daily Living Profile (MG-ADL) score from baseline compared to placebo, which is the primary endpoint.

The drug showed a safety profile that is consistent with that observed in Phase 3 trials in paroxysmal nocturnal haemoglobinuria (PNH) and atypical haemolytic uraemic syndrome (aHUS).

Upper respiratory tract infection and diarrhoea are the most common adverse reactions observed in patients receiving Ultomiris.

CHAMPION-MG trial lead primary investigator professor James Howard Jr said: “Despite recent advances, managing gMG is complex. Earlier intervention can preserve function and quality of life.

“This approval offers patients, including those with milder symptoms, a long-acting C5 inhibitor with early-onset and reliable efficacy.”

AstraZeneca said that its regulatory submissions for Ultomiris to treat gMG are currently being reviewed by multiple health authorities, including in the European Union (EU) and Japan.