Alexion, AstraZeneca Rare Disease, will present four abstracts, including one oral presentation, from its leading rare neurology portfolio at the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) Annual Congress in Barcelona, Spain, 24 to 26 September 2025.

Presentations will highlight the final long-term analysis of the CHAMPION-NMOSD Phase III trial as well as real-world data further supporting the safety profiles and efficacy of Ultomiris (ravulizumab) and Soliris (eculizumab) in adult patients with anti-aquaporin-4 (AQP4) antibody-positive (Ab+) neuromyelitis optica spectrum disorder (NMOSD).

Christophe Hotermans, Head of Global Medical Affairs, Alexion, said: "At ECTRIMS, new long-term clinical and real-world evidence will reinforce the potential of Ultomiris to eliminate relapses in most patients and elevate the standard of care for people living with AQP4-Ab+ NMOSD. From the final results of the CHAMPION-NMOSD Phase III trial to global, real-world Ultomiris and Soliris data, these presentations highlight Alexion's continued commitment to reducing the burden of this debilitating disease and our aspiration to revolutionise what living with NMOSD can look like."

Sean Pittock, MD, Mayo Clinic Glenn W. and Katherine K. Hasse Chair Neurology, Applebaum Family Professor of Neuroscience, Professor of Neurology, Co-Director of the Neuroimmunology Laboratory and principal investigator in the CHAMPION-NMOSD Phase III trial, said: "These long-term data from the CHAMPION-NMOSD Phase III trial show that patients treated with Ultomiris remained relapse-free for more than three years, a significant achievement in a disease where every relapse can lead to permanent disability. It's an honour to have these findings recognised as part of the `Best of ECTRIMS 2025', underscoring the potential impact of these results in improving outcomes for patients with NMOSD."

Completion of CHAMPION-NMOSD Phase III trial long-term extension shows maintained relapse prevention with Ultomiris

An oral presentation of the final safety and efficacy results from the long-term extension (LTE) of the global CHAMPION-NMOSD Phase III trial will demonstrate zero adjudicated on-trial relapses (OTR) in adults with AQP4-Ab+ NMOSD treated with Ultomiris through the median follow-up of 170.3 weeks (relapse risk reduction: 98.9%, hazard ratio (95% CI), 91.8-100; P < 0.0001). As one of the longest studies conducted in NMOSD, these data will reinforce the long-term clinical benefit of C5 inhibition with Ultomiris.

Additionally, most patients treated with Ultomiris were clinically stable (81%) or improved (13.8%), as measured by the Hauser Ambulation Index (HAI) score, and had no clinically important worsening (91.4%) of disability measured with the Expanded Disability Status Scale (EDSS). Further, the data will show that 63% (17/27) of patients taking immunosuppressive therapy (IST) at baseline reduced their dose or discontinued at least one treatment, indicating a potential for reduced use IST while being treated with Ultomiris long-term. The safety profile was consistent with prior study analyses.

Robust real-world evidence builds on the established benefits of C5 inhibition in NMOSD

A virtual poster presentation will feature real-world clinical findings from the global NMO SPOTLIGHT Registry, showing that Ultomiris and Soliris led to a reduction in relapses for people with AQP4-Ab+ NMOSD. Among 56 adults, the annualised relapse rate (ARR) fell from 0.50 [95% CI: 0.33-0.72] during the year prior to starting treatment with Ultomiris or Soliris to 0.02 [95% CI: 0.00-0.05] while on treatment, with no one experiencing more than one relapse. Among patients who switched from rituximab (n=15), no relapses were reported while treated with Ultomiris or Soliris, compared to an ARR of 0.47 [95% CI: 0.19-0.96] in the year prior to switching. These findings highlight the strong real-world clinical benefit of Ultomiris and Soliris in relapse prevention.

A separate poster presentation will share interim analysis results from a real-world study from Japan evaluating Ultomiris in patients with AQP4-Ab+ NMOSD who had a suboptimal response to satralizumab. Among 11 patients receiving Ultomiris for at least six months (10.9±1.4 months on average), 10 remained relapse-free. In addition, use of concomitant immunosuppressive drugs was reduced in all patients. The switch to Ultomiris also showed positive changes in inflammatory biomarkers, as measured by changes in CD19+CD27-IgD- double negative B cells (%DNB) and unswitched memory B cells (%USM) at two months follow-up after treatment initiation.

Lastly, a virtual poster presentation will share findings from the ongoing AMAZE study, a 78-week observational trial to evaluate the biological effects of Ultomiris, on clinical, serological and radiological measures of disease, and better understand the impact of social determinants of health on access to care and treatment outcomes for living with AQP4-Ab+ NMOSD. Upon study completion, these data may help guide clinicians towards optimised and equitable healthcare practices for people living with AQP4-Ab+ NMOSD.

Notes

Alexion
Alexion, AstraZeneca Rare Disease, is focused on serving patients and families affected by rare diseases and devastating conditions through the discovery, development and delivery of life-changing medicines. A pioneering leader in rare disease for more than three decades, Alexion was the first to translate the complex biology of the complement system into transformative medicines, and today it continues to build a diversified pipeline across disease areas with significant unmet need, using an array of innovative modalities. As part of AstraZeneca, Alexion is continually expanding its global geographic footprint to serve more rare disease patients around the world. It is headquartered in Boston, US.

AstraZeneca
AstraZeneca (LSE/STO/Nasdaq: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca's innovative medicines are sold in more than 125 countries and used by millions of patients worldwide. Please visit astrazeneca.com and follow the Company on social media @AstraZeneca

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