Satralizumab: A Review in Neuromyelitis Optica Spectrum Disorder

Satralizumab (Enspryng®) is a monoclonal antibody that blocks the interleukin-6 (IL-6) receptor and is approved for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in patients who are aquaporin-4 immunoglobulin G (AQP4-IgG) seropositive. Patients with NMOSD are at risk of recurrent autoimmune attacks that primarily target the optic nerves and spinal cord but may also target other regions of the central nervous system; these attacks can lead to life-long disability. In the randomized, placebo-controlled phase III SAkuraSky and SAkuraStar trials, subcutaneous satralizumab as an add-on to immunosuppressive therapy or as a monotherapy, respectively, significantly reduced the risk of relapse compared with placebo in patients who were AQP4-IgG seropositive with NMOSD. Satralizumab was well tolerated; the most common adverse events were infection, headache, arthralgia, decreased white blood cell count, hyperlipidaemia and injection-related reactions. In the EU, satralizumab is the first IL-6 receptor blocker to be approved for treatment of AQP4-IgG-seropositive patients with NMOSD, has the potential advantage of subcutaneous administration, and is the only targeted treatment approved for adolescent patients with this disorder. Thus, satralizumab is a valuable treatment option for patients with NMOSD. Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder, in which recurrent attacks by the body’s own immune system can cause severe morbidity and disability. Immunoglobulin G antibodies targeting the aquaporin-4 (AQP4-IgG) water channel in cells of the central nervous system can be detected in the majority of patients with NMOSD. Satralizumab (Enspryng®), which is designed to suppress autoantibody production by blocking the interleukin-6 (IL-6) receptor, was found to significantly reduce the rate of immune attack recurrence compared with placebo when used as an add-on to standard immunosuppressive therapy (SAkuraSky trial) or when used alone (SAkuraStar trial). Satralizumab was well tolerated in the SAkuraSky and SAkuraStar trials, with infections (e.g. nasopharyngitis, upper respiratory tract infections) being the most common associated adverse event. In the EU, satralizumab is the first IL-6 receptor blocker approved for AQP4-IgG-seropositive patients with NMOSD and is the only subcutaneously administration targeted drug approved for NMOSD. Therefore, satralizumab represents a valuable treatment option for NMOSD.