The European Medicines Agency has granted orphan drug designation to inebilizumab (formerly MEDI-551) for the treatment of neuromyelitis optica spectrum disorder. Developed by MedImmune, inebilizumab is currently in Phase IIb clinical development for NMOSD.
Research has shown that patients with NMOSD develop antibodies against a protein called aquaporin-4 in their optic nerve and spinal cord. The antibodies play a key role in NMOSD disease pathogenesis. Inebilizumab directly targets and depletes cells that produce the antibodies.
The FDA granted an orphan drug designation in March 2016.