AstraZeneca’s potential medicine for neuromyelitis optica receives FDA Orphan Drug Designation

AstraZeneca and its global biologics research and development arm, MedImmune, today announced that the US Food and Drug Administration (FDA) has granted Orphan Drug Designation for the investigational anti-CD19 monoclonal antibody, MEDI-551, for the treatment of patients with neuromyelitis optica (NMO) as well as neuromyelitis optica spectrum disorders (NMOSD). Developed by MedImmune, MEDI-551 is currently in Phase IIb clinical development for NMO.

NMO is a rare, life-threatening autoimmune disease of the central nervous system in which the body’s immune system attacks healthy cells, most commonly in the optic nerves and spinal cord, resulting in severe damage. NMO causes severe muscle weakness and paralysis, loss of vision, respiratory failure, problems with bowel and bladder function and neuropathic pain.[1] There is currently no cure or approved medicine for NMO, which affects about five in 100,000 people.

Bing Yao, Senior Vice President, R&D and Head of the Respiratory, Inflammation and Autoimmunity Innovative Medicines unit, MedImmune, said: “The orphan designation for MEDI-551 underscores the significant need for an effective medicine for NMO, a rare, devastating disease which causes increasing damage and disability with each attack. MEDI-551 has a unique, targeted mechanism of action offering potential for the treatment of NMO. We look forward to working with the FDA to advance MEDI-551 to patients suffering from NMO as quickly as possible.”

Research has shown that patients with NMO and NMOSD develop antibodies against a protein in their body called aquaporin-4, and these antibodies play a key role in NMO disease pathogenesis. MEDI-551 directly targets and depletes cells that produce these antibodies.

The FDA’s Orphan Drug Designation programme provides orphan status to potential medicines intended for the safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the US[2].


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About MEDI-551

MEDI-551 is a humanised, monoclonal antibody that binds with high affinity to CD19, a protein expressed on a broad range of B cells, including certain B cells called plasmablasts. Research has shown that autoantibodies called AQP4-Ab (or NMO-IgG) to the protein aquaporin-4 - produced in these plasmablasts - play a key role in NMO disease pathogenesis. MEDI-551 binds directly to CD19 protein on the surface of the plasmablasts and depletes them. MEDI-551 is currently being evaluated in a global clinical trial in Neuromyelitis Optica (NMO) and Neuromyelitis Optica Spectrum Disorders. MEDI-551 is also being studied in a Phase II trial in diffuse B-cell lymphoma. More information on the MEDI-551 NMO clinical trial can be found

About Neuromyelitis Optica (NMO) and Neuromyelitis Optica Spectrum Disorders (NMOSD)

NMO is a severe, rare, autoimmune disease that can be fatal. In NMO, immune system cells and antibodies attack cells in the optic nerves and spinal cord. The damage to the optic nerves produces swelling and inflammation that cause pain and loss of vision; the damage to the spinal cord can cause weakness, paralysis, loss of sensation, problems with bladder and bowel function, and respiratory failure, with each attack leading to further damage and disability.[3]Currently available data demonstrate that the prevalence of NMO is close to 5 out of 100,000 people[4]. It primarily affects women and it may be more common in non-Caucasians. There is currently no cure or approved treatment for NMO. Neuromyelitis optica spectrum disorders (NMOSD) is a recent unifying term for NMO and related syndromes.

About MedImmune

MedImmune is the global biologics research and development arm of AstraZeneca, a global, innovation-driven biopharmaceutical business that focuses on the discovery, development and commercialization of small molecule and biologic prescription medicines. MedImmune is pioneering innovative research and exploring novel pathways across key therapeutic areas, including respiratory, inflammation and autoimmunity; cardiovascular and metabolic disease; oncology; neuroscience; and infection and vaccines. The MedImmune headquarters is located in Gaithersburg, Md., one of AstraZeneca’s three global R&D centers, with additional sites in Cambridge, UK and Mountain View, CA. For more information, please visit

About AstraZeneca

AstraZeneca is a global, innovation-driven biopharmaceutical business that focuses on the discovery, development and commercialisation of prescription medicines, primarily for the treatment of diseases in three main therapy areas - respiratory, inflammation, autoimmune disease (RIA), cardiovascular and metabolic disease (CVMD) and oncology – as well as in infection and neuroscience. AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. For more information please



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Key: RIA - Respiratory, Inflammation and Autoimmunity, CVMD - Cardiovascular and Metabolic Disease,

ING - Infection, Neuroscience and Gastrointestinal

[1] National Institute of Neurological Disorders and Stroke, National Institutes of Health 

[2] US Food and Drug Administration. Developing Products for Rare Diseases & Conditions

[3] National Institute of Neurological Disorders and Stroke, National Institutes of Health



  • Inflammation och autoimmunitet