FDA Approves Satralizumab for Neuromyelitis Optica Spectrum Disorder Treatment

The Food and Drug Administration (FDA) has approved satralizumab (Enspryng; Genentech, South San Francisco, CA) as the first and only subcutaneous treatment for adults who test positive for antibodies to aquaporin-4 (antiAQP4+) and have neuromyelitis optica spectrum disorder (NMOSD). Satralizumab can be administered in the home by a person living with NMOSD or a caregiver following training from a healthcare provider. Satralizumab treatment is administered every 4 weeks after an initial loading dose.

“Today’s FDA approval of Enspryng, the first subcutaneous NMOSD treatment using novel recycling antibody technology, builds upon the work we’ve done in multiple sclerosis (MS) with 
ocrelizumab (Ocrevus; Genentech) to develop first-in-class medicines and further the scientific understanding of neuroimmunologic diseases,” said Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development. “We thank the NMOSD community, including patients and investigators who participated in Enspryng clinical trials.”

This approval is supported by results from 2 randomized controlled phase 3 clinical trials, the SAkuraStar (NCT020737279) and SAkuraSky (NCT02028884) studies. In the SAkuraStar monotherapy study, 76.5% of participants treated with satralizumab were relapse-free at 96 weeks compared with 41.1% of those treated with placebo. In the SAkuraSky study, which evaluated satralizumab when used concurrently with baseline immunosuppressive therapy, 91.1% of participants treated with satralizumab were relapse-free at 96 weeks compared with 56.8% of those treated with placebo.In both studies, all participants were antiAQP4+ with NMOSD. The primary endpoint of both SAkuraStar and SAkuraSky was time to first protocol-defined relapse (PDR) adjudicated by an independent review committee in the double-blind period.

The most common adverse reactions with satralizumab were nasopharyngitis, headache, upper respiratory tract infection, gastritis, rash, arthralgia, extremity pain, fatigue, and nausea. 
Satralizumab is a humanized monoclonal antibody and the only approved therapy for NMOSD designed to target and inhibit interleukin-6 (IL-6) receptor activity, believed to play a key role in the inflammation associated with NMOSD. The treatment was designed using novel recycling antibody technology, which, compared to conventional technology, allows for longer duration of antibody circulation and subcutaneous dosing every 4 weeks.