The therapy received fast track designation and was approved in just over 1 year.
The FDA has approved satralizumab-mwge (Enspryng; Genentech) for the treatment of neuromyelitis optica spectrum disorder (MNOSD) in adults who are anti-aquaporin-4 (AQP4) antibody-positive, making it the third approved treatment for the disorder.
The drug received fast track designation to address the unmet medical need for MNOSD; it was approved by the agency in just over a year.
NMOSD, a rare autoimmune disease, affects an estimated 4000 to 8000 Americans. Patients with NMOSD exhibit changes to the immune system, in which it mistakenly attacks healthy cells and proteins in the body, most often within the optic nerves and spinal cord. Antibodies binding to the AQP4 protein may activate subsequent immune system components directing to inflammation and damage to the central nervous system.
It is typical in those with NMOSD to experience attacks of optic neuritis, leading to eye pain and vision loss; about 50% of patients with NMOSD suffer permanent visual impairment and paralysis.
The approval was based on two 96-week clinical studies evaluating the safety and efficacy of satralizumab-mwge. The first study incorporated 95 adult patients with NMOSD who showed the presence of antibodies against AQP4 (anti-AQP4 positive). According to the results, satralizumab-mwge reduced the number of NMOSD relapses by 74% in patients who were anti-AQP4 positive compared with placebo.
The second study incorporated 76 patients; 52 patients were anti-AQP4 positive. Satralizumab-mwge similarly showed reduced relapse rates in anti-AQP4 positive patients; in this study, the number of relapses diminished by 78% compared with placebo treatment.
“Until last year, there were no FDA-approved treatments for patients with this rare, debilitating and sometimes fatal disease. Now there are three,” said Billy Dunn, MD, director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research. “Today’s approval of Enspryng highlights the FDA’s commitment to rapidly advancing safe and effective therapies for NMOSD and other neurological diseases.”