Ultomiris is a long-acting C5 complement inhibitor that provides immediate, complete and sustained complement inhibition.
It is indicated for adult gMG patients, who are anti-acetylcholine receptor (AChR) antibody-positive, and whose symptoms are difficult to control with high-dose intravenous immunoglobulin therapy (IVIg) or plasmaphaeresis.
The Pharmaceuticals and Medical Devices Agency of Japan also indicated that the therapy can be used for patients who cannot receive high-dose IVIg or plasmaphaeresis due to adverse reactions, complications, or other factors.
The regulatory approval was based on data obtained from the double-blind, placebo-controlled, randomised, multicentre CHAMPION-MG Phase III trial that enrolled 175 participants across North America, Europe, Asia-Pacific and Japan.
In the study, Ultomiris showed improvement in the Myasthenia Gravis-Activities of Daily Living Profile (MG-ADL) total score from baseline compared to placebo at week 26.
The therapy’s safety profile was consistent with that observed in Phase III trials in paroxysmal nocturnal haemoglobinuria (PNH) and atypical haemolytic uraemic syndrome (aHUS).
AstraZeneca subsidiary Alexion CEO Marc Dunoyer said: “We are pleased that Ultomiris is now approved in Japan for adults with gMG, a disease that may impact their ability to work, meet family obligations and live their lives fully.
“The approval speaks to the strength and consistency of Ultomiris clinical data as demonstrated in the global CHAMPION-MG Phase III trial.
“We look forward to bringing this treatment option to people living with gMG in Japan as part of our broader strategy to expand global access to our medicines.”
Nausea, headache, and diarrhoea are the most common adverse reactions observed in patients receiving Ultomiris.