FDA grants orphan drug status to MedImmune’s MEDI-551 neuromyelitis optica drug

MEDI-551 is an anti-CD19 monoclonal antibody indicated to treat neuromyelitis optica and neuromyelitis optica spectrum disorders.

The drug is presently in phase IIb clinical development for treating NMO, an autoimmune disease of the central nervous system by which the body’s immune system attacks healthy cells, most commonly in the optic nerves and spinal cord.

Research has demo started that patients with NMO and NMOSD develop antibodies against a protein in their body called aquaporin-4.

MEDI-551 directly targets and depletes cells that produce the antibodies, which play an important role in NMO disease pathogenesis.

NMO, which affects around five in 100,000 people, results in severe muscle weakness and paralysis, loss of vision, respiratory failure, problems with bowel and bladder function and neuropathic pain.

It primarily affects women and it is expected to be more common in non-Caucasians.

MedImmune senior vice president, R&D and head of the respiratory, inflammation and autoimmunity innovative medicines unit Bing Yao 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."

MedImmune is the global biologics research and development arm of AstraZeneca.

The company recently received fast track designation from the FDA for its investigational human monoclonal antibody, MEDI8852, to treat patients hospitalised with Type A strain influenza.

Image: MedImmune, Gaithersburg USA. Photo: courtesy of AstraZeneca.