Trial finds NMOSD treatment prevents disease relapses for years

A global clinical trial testing Ultomiris (ravulizumab-cwvz) in adults with neuromyelitis optica spectrum disorder (NMOSD) found that the treatment kept patients free of relapses for more than 4.5 years.

When compared with data from an external group of NMOSD patients given a placebo in a previous trial, the findings indicate a relative reduction in relapse risk of 98.9% with Ultomiris.

Data from the first two-year portion of the Phase 3 trial, CHAMPION-NMOSD (NCT04201262), formed the basis for Ultomiris’ regulatory approvals to treat NMOSD in adults positive for self-reactive antibodies targeting the AQP4 protein, the most common type of NMOSD-driving antibody.

Final data from the 243-week trial were published in Neurology Neuroimmunology and Neuroinflammation, in a study titled “Long-Term Ravulizumab Efficacy and Safety in AQP4 Antibody–Positive Neuromyelitis Optica Spectrum Disorder.” The work was funded by Alexion, AstraZeneca Rare Disease, the company that markets Ultomiris.

Treatment for more than three years “continued to show significant relapse risk reduction in patients with [AQP4-related] NMOSD, and the safety profile was consistent with the known safety profile for [Ultomiris],” the researchers wrote.

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June 10, 2026 Columns by Jennifer V.

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Burdensome symptoms

NMOSD is an inflammatory disorder that causes damage to the spinal cord and optic nerves, which relay signals between the brain and eyes. In most cases, NMOSD is caused by self-reactive antibodies targeting AQP4, a protein highly present in neuron-supporting cells.

Patients may experience disease relapses, or flares, when NMOSD symptoms suddenly worsen or new symptoms appear. Often, patients do not fully recover after relapses, leading to long-lasting symptoms that can be disabling and pose a substantial burden on quality of life. NMOSD relapses are also costly to manage and pose a substantial burden on the healthcare system.

Ultomiris is an infusion therapy that works by blocking activation of the complement cascade, a group of immune proteins that contributes to NMOSD-related damage. It is approved in the U.S. and other regions for adults with NMOSD and anti-AQP4 antibodies.

The CHAMPION-NMOSD study enrolled 58 adults with AQP4-related NMOSD who had experienced at least one relapse in the previous year. All participants were treated with Ultomiris, with the first two infusions given two weeks apart and subsequent infusions every other month.

The trial’s first part, completed after all participants had completed nearly a year of treatment or discontinued before that time, lasted little over two years.

Results from this part were compared with data from an external group of 47 patients who received a placebo in the Phase 3 PREVENT trial (NCT01892345), the findings of which supported approvals of Soliris (eculizumab), Alexion’s older treatment, for AQP4-related NMOSD. These patients had been followed for a median of eight months, and for as long as two years.

That comparison showed that CHAMPION-NMOSD met its main goal, with Ultomiris being associated with a 98.6% drop in the risk of relapse relative to the placebo.

Fifty-six participants chose to enter CHAMPION-NMOSD’s long-term extension (LTE) portion, in which they continued to receive Ultomiris for up to two years. All but one of these patients completed the LTE. During the whole trial, patients were followed for a median of 170.3 weeks (little over three years) and up to 243 weeks (more than 4.5 years).

Over this time, none of the patients experienced any relapses while on Ultomiris, reflecting a 98.9% reduction in the risk of relapse relative to the external placebo group. In addition, nearly all trial participants had stable or improved scores in measures of physical disability at the end of the study.

Most (63%) of those who were taking other immunosuppressive drugs at the trial’s start were able to discontinue or reduce the dose of at least one such medication at any time during the study.

Over the course of the trial, the most commonly reported safety issues were headaches and infections. Nearly half of the participants (46.6%) experienced adverse events deemed related to Ultomiris.

“The safety profile of [Ultomiris] during the LTE was consistent with that seen during the [first part of the trial], and no new safety concerns were identified,” the researchers wrote.

Four serious infections related to Ultomiris were reported; one led to treatment discontinuation. One patient died of heart disease during the trial, but the person had a history of heart problems, and the death was judged as unrelated to Ultomiris.

“Given the crucial role of effective and well-tolerated treatments in relapse prevention, the end of CHAMPION-NMOSD study results demonstrates that [Ultomiris] has the potential to not only lower disease burden for patients but also reduce treatment burden through its extended 8-week dosing period, ultimately lowering health care resource utilization and the overall relapse-associated cost, as well as generally improving patients’ quality of life,” the researchers concluded.