AstraZeneca’s Ultomiris Wins FDA Approval for Rare Autoimmune Disease

AstraZeneca Building in Gothenburg/iStock

Pictured: AstraZeneca signage at its office in Sweden/iStock, Wirestock

The FDA on Monday approved the label expansion for AstraZeneca’s complement inhibitor Ultomiris (ravulizumab-cwvz), allowing its use for the treatment of adult neuromyelitis optica spectrum disorder patients positive for anti-AQP4 antibodies.

Monday’s approval makes Ultomiris the first and only long-acting C5 complement inhibitor for this indication that provides patients with the possibility of living relapse-free, according to the company’s announcement.

Marc Dunoyer, CEO of AstraZeneca’s rare disease unit Alexion, in a statement called Ultomiris a “transformative” treatment option for neuromyelitis optica spectrum disorder (NMOSD) with the “potential to eliminate relapses with a convenient dosing schedule every eight weeks.”

Ultomiris’ label expansion is supported by data from the Phase III CHAMPION-NMOSD trial, a global, open-label and multicenter trial with 58 NMOSD patients enrolled, all of whom were confirmed to be positive for anti-AQP4 antibodies and had had at least one attack or relapse in the 12 months before screening.

Given the potential long-term consequences of NMOSD relapses, AstraZeneca and Alexion could not ethically include a direct placebo arm into CHAMPION-NMOSD. Instead, the company used data from the placebo arm of the PREVENT trial for its other NMOSD therapy Soliris (eculizumab).

Findings from CHAMPION-NMOSD were published in March 2023 in the journal Annals of Neurology. Data showed that Ultomiris met its primary efficacy endpoint, preventing relapse in all 58 treated patients over a median follow-up period of 73.5 weeks, compared to 20 relapses in PREVENT’s placebo arm.

In relative terms, Ultomiris reduced the risk of relapse by 98.6% versus PREVENT’s placebo.

In terms of safety, Ultomiris was overall well-tolerated and most treatment-emergent events in CHAMPION-NMOSD were mild or moderate in severity. Two patients treated with the complement inhibitor developed meningococcal infections, both of whom recovered with no sequelae. No patients died due to treatment toxicities.

Affecting around 6,000 patients in the U.S., NMOSD is a rare autoimmune disorder that arises when the body’s immune system attacks the protective myelin sheaths surrounding neurons. NMOSD most often affects the central nervous system, particularly the spine and optic nerves, and to a lesser degree the brain.

NMOSD manifests as weakness in the limbs, painful spasms, uncontrollable vomiting, bowel dysfunction and sleeping problems. Patients with NMOSD often experience unpredictable relapses including new or worsening neurological symptoms.

Through its rare disease unit Alexion, AstraZeneca’s NMOSD portfolio includes Soliris, which is a monoclonal antibody that targets the C5 complement protein, suppressing a central cascade in the immune response and preventing the body from attacking the central nervous system. Ultomiris is also a monoclonal antibody that works via the same mechanism of action.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at or

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