AstraZeneca Gains FDA Nod for Ultomiris, a Treatment for Managing NMOSD

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FDA has approved AstraZeneca's Ultomiris, marking the first and only long-acting C5 complement inhibitor for patients with NMOSD.

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FDA has approved Ultomiris (ravulizumab-cwvz), making it the first and only long-acting C5 complement inhibitor in the United States for treating adult patients with anti-aquaporin-4 (AQP4) antibody-positive (Ab+) neuromyelitis optica spectrum disorder (NMOSD). AstraZeneca announced the approval on March 25, 2024.

The approval was based on positive results from a Phase III trial (CHAMPION-NMOSD) that showed Ultomiris met the primary endpoint of time to first on-trial relapse. Zero relapses were observed among patients treated with Ultomiris. The median treatment duration was 73 weeks with a relapse risk reduction of 98.6%.

Sean J. Pittock, the director of the Mayo Clinic's Center for Multiple Sclerosis and Autoimmune Neurology and of Mayo's Neuroimmunology Laboratory and lead primary investigator in the Phase III trial, said in the press release that, “C5 inhibition has been proven to offer efficacy in reducing the risk of NMOSD relapses by blocking the complement system, a part of the immune system, from attacking healthy cells in the spinal cord, optic nerve, and brain. With today’s FDA approval, patients now have the option of a long-acting C5 inhibitor treatment that showed zero relapses in the pivotal CHAMPION-NMOSD trial, supporting the primary goal of relapse prevention in treating NMOSD.”

Ultomiris is also approved for certain adults with NMOSD in Japan and the European Union, while regulatory reviews in additional countries remain ongoing.


NMOSD is known to be a rare and debilitating autoimmune disease. It affects the central nervous system, including the spine and optic nerves. Most people living with the disease experience unpredictable relapses, which involve a new onset of neurologic symptoms or the worsening of existing neurologic symptoms. These relapses tend to be severe and recurrent and carry the risk of causing permanent disability. Approximately 6000 adults in the US are estimated to be affected by NMOSD, according to AstraZeneca in the press release.

“Alexion has been at the forefront of innovation in NMOSD, striving to offer patients a future without fear of life-altering or even fatal relapses. Building on the established efficacy of C5 inhibition for people living with AQP4 Ab+ NMOSD, we are proud to deliver a transformative, long-acting treatment option that has the potential to eliminate relapses with a convenient dosing schedule every eight weeks. We are grateful to the NMOSD community for their ongoing collaboration and input, which enables us to advance science for rare diseases,” said Marc Dunoyer, chief executive officer, Alexion, the group within AstraZeneca focused on rare diseases, in the press release.

The rare disease group was created following the completion of AstraZeneca’s approximately $13.3 billion acquisition of Alexion Pharmaceuticals in 2021 (1). With the acquisition, AstraZeneca strengthened its scientific presence in immunology, allowing the company to address the significant unmet medical need in the rare diseases sector. Alexion’s focus is on research in novel molecules aimed toward development of therapeutics for hematology, nephrology, neurology, metabolic disorders, cardiology, and ophthalmology.


1. AstraZeneca. Acquisition of Alexion Completed. Press Release, July 21, 2021.

Source: AstraZeneca