Breakthrough Therapy Designation for Neuromyelitis Optica Spectrum Disorder Drug Candidate

Possible First Treatment Option for Rare Autoimmune Disease of the CNS

The FDA has awarded a breakthrough therapy designation for Viela Bio’s inebilizumab, an investigational monotherapy for neuromyelitis optica spectrum disorder (NMOSD). The rare, life-threatening autoimmune disease of the central nervous system currently has no cure or approved treatment.

In NMOSD, the immune system attacks healthy cells, usually in the optic nerves and spinal cord, resulting in serious damage. NMOSD can cause muscle weakness and paralysis, vision loss, respiratory failure, problems with bowel and bladder function, and neuropathic pain. The disease is more common in women and may be more common in non-Caucasians.

The designation was based on results from the largest monotherapy study ever conducted in NMOSD—the pivotal N-MOmentum trial. Inebilizumab is a humanized monoclonal antibody that binds with high affinity to the CD19 protein and depletes a wide range of B cells, including autoantibody-secreting plasmablasts and CD19-expressing plasma cells.

N-MOmentum enrolled 231 NMOSD patients who were randomized to receive two intravenous doses of inebilizumab monotherapy or placebo and followed for 6.5 months. Patients were then placed into an open-label extension in which all of them received inebilizumab every six months. The primary endpoint was time from treatment initiation to occurrence of an NMOSD attack. An open-label study is ongoing, with patients receiving inebilizumab every six months.

Source: Viela Bio, April 18, 2019