AstraZeneca's Klygefa drug recommended for EU approval by CHMP

For best results when printing this announcement, please click on link below: RNS Number: 4424V AstraZeneca PLC 21 September 2026 21 September 2026 Klygefa (gefurulimab) recommended for approval in the EU by CHMP for the treatment of adults with generalised myasthenia gravis (gMG) Recommendation based on PREVAIL Phase III trial demonstrating statistically significant and clinically meaningful improvement in Myasthenia Gravis Activities of Daily Living score If approved, Klygefa will be the first and only dual-binding nanobody C5 inhibitor for gMG in the EU, offering once weekly subcutaneous self-administration with rapid and sustained symptom control Alexion, AstraZeneca Rare Disease's Klygefa (gefurulimab) has been recommended for approval in the European Union (EU) as an add-on to standard therapy for the treatment of generalised myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) antibody-positive.

If approved, Klygefa will be the first and only dual-binding nanobody C5 inhibitor for this patient population. (3) Tobias Ruck, MD, Director Department of Neurology, BG University Hospital Bergmannsheil Bochum, Ruhr-University Bochum and investigator in the trial, said: "For people living with gMG, unpredictable symptoms can quickly become incapacitating or life-threatening. In the PREVAIL Phase III trial, gefurulimab demonstrated the ability to improve measures of disease severity and daily function with the convenience of once weekly subcutaneous self-administration, as early as one week and through the 26-week study period.

" Marc Dunoyer, Chief Executive Officer, Alexion, said: "This positive CHMP opinion is an important step towards bringing Klygefa, an innovative dual-binding nanobody C5 inhibitor, to people living with gMG in the EU. 0001). (1) Klygefa is approved in Japan and other countries for certain adults with gMG. Regulatory submissions based on the PREVAIL results are under review in the US, China and additional countries.

(7,8) PREVAIL (ALXN1720-MG-301) PREVAIL (ALXN1720-MG-301) is a global, Phase III, randomised, double-blind, placebo-controlled, parallel, multicentre study evaluating the safety and efficacy of Klygefa in adults with generalised myasthenia gravis (gMG). The trial enrolled 260 patients from 20 countries across North America, Europe, Asia and the Pacific region. (9) Patients were randomised 1:1 to receive Klygefa or placebo for a total of 26 weeks in the randomised controlled treatment period. Patients received a single weight-based loading dose on Day 1, followed by regular weight-based maintenance dosing beginning on Day 8 and once every week thereafter.

(9) Klygefa (gefurulimab) Klygefa (gefurulimab), a complement C5 inhibitor, is a novel dual-binding nanobody optimised for subcutaneous self-administration in development as a treatment for AChR-Ab+ gMG. The medication works by binding to the C5 protein in the terminal complement cascade, a part of the body's immune system. When activated in an uncontrolled manner, the complement cascade over-responds, leading the body to attack its own healthy cells. Klygefa's concurrent binding to serum albumin provides an extended half-life, enabling once-weekly dosing.

Klygefa is approved in Japan and other countries for certain adults with gMG. Regulatory submissions based on the PREVAIL results are under review in the US, China and additional countries. 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/NYSE: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Disease, 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. com and follow the Company on Social Media @AstraZeneca ( ). Contacts For details on how to contact the Investor Relations Team, please click here ( ).

For Media contacts, click here ( ). References 1. Gwathmey KG, Saccà F, Howard JF Jr, et al. Efficacy and safety of gefurulimab in generalized myasthenia gravis: the PREVAIL phase 3 randomized clinical trial.

JAMA Neurol. 2026 Jul 27. 2. Jung-Plath W, et al.

Assessment of myasthenia gravis patients' quality of life. The Journal of Neurosurgical Nursing. 2023;12(2):74-83. 3.

AstraZeneca Data on File - Epidemiology estimates are composed of a triangulation of different data sources including Data Monitor, Decision Resources Group, Kantar Health, and internal input. Available here ( ). Accessed September 2026. 4.

Lazaridis K, et al. Myasthenia gravis: autoantibody specificities and their role in MG management. Front Neurol. 2020;11:596981.

5. Huang YF, et al. Visualization and characterization of complement activation in acetylcholine receptor antibody seropositive myasthenia gravis. Muscle Nerve.

2024. 6. Cavanagh N, et al. Exploring the impairments and allied health professional utilization in people with myasthenia gravis: a cross-sectional study.

J Clin Neurosci. 2023;114:9-16. 7. Catalin J, et al.

Clinical presentation of myasthenia gravis. Thymus. 2019. 8.

Farid ZR, et al. Factors affecting generalization of ocular myasthenia gravis. Sriwijaya Journal of Ophthalmology. 2020;3(2):48-54.

9. gov. Safety and efficacy of ALXN1720 in adults with generalized myasthenia gravis. NCT Identifier: NCT05556096.

Available here ( ). Accessed September 2026. Matthew Bowden Company Secretary AstraZeneca PLC This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom.

Terms and conditions relating to the use and distribution of this information may apply. com) or visit ( ). RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our Privacy Policy ( ).

END MSCGPUMGBUPQGCR