The FDA approved Enspryng (satralizumab-mwge), developed by Genentech, Inc., a member of the Roche Holding AG (RHHBY) on August 14, 2020, for the treatment of adults with anti-aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD).NMOSD is a rare, lifelong, and debilitating autoimmune disorder of the central nervous system, that primarily damages the optic nerves and spinal cord, causing blindness, muscle weakness, and paralysis.Enspryng is a humanized monoclonal antibody that targets interleukin-6 (IL-6) receptor activity. This is the first subcutaneous NMOSD treatment using novel recycling antibody technology, which, compared to conventional technology, allows for a longer duration of antibody circulation.The wholesale acquisition cost for Enspryng is about $220,000 for the 15 doses required in the first year and $190,000 for subsequent years when 13 doses are needed.The drug will have to compete with Alexion's Soliris, which was approved last year and Viela Bio's Uplizna approved in June this year for the treatment of NMOSD.Enspryng is approved in Canada, Japan, and Switzerland. Applications are under review with various regulators, including in the European Union and China.