The Food and Drug Administration has approved a drug for treating a rare autoimmune disorder that can cause blindness, muscle weakness and paralysis.
Basel, Switzerland-based Roche said Monday that the FDA had approved Enspryng (satralizumab-mwge), a subcutaneous monoclonal antibody that targets IL-6 in patients with neuromyelitis optica spectrum disorder, or NMOSD, positive for anti-acquaporin-4 antibodies. The disease is an autoimmune disorder of the central nervous system often misdiagnosed as multiple sclerosis that mainly damages the optic nerves and spinal cord, Roche said.
“For people with NMOSD, relapses can cause devastating, irreversible and disabling neurological effects,” said Enspryng clinical trial investigator and professor of neurology and ophthalmology at the University of Colorado Jeffrey Bennett, in a statement. “Having an approved therapy that can be administered subcutaneously in the home and has demonstrated an impact on the frequency of relapses is an important advancement for patients.”
According to the National Organization for Rare Disorders, NMOSD affects about one to 10 individuals per 100,000 and occurs worldwide, but has been reported at higher frequencies in people of African and Asian descent. Existing treatments for the disease include corticosteroids, azathioprine, mycophenolate mofetil and another Roche drug, Rituxan (rituximab). According to NORD, Rituximab – which is used to treat some autoimmune disorders in addition to B-cell non-Hodgkin’s lymphomas – has been shown to be helpful in retrospective studies, especially among people who have failed immunosuppressive treatments. However, certain immunosuppressive drugs used to treat multiple sclerosis, such as interferon beta, are ineffective and may even be harmful.
The approval was based on two Phase III studies, SAkuraStar and SAkuraSky, which were randomized, double-blind, placebo-controlled trials that investigated Enspryng as a monotherapy in NMOSD and as an add-on to baseline immunosuppressant therapies, respectively. Both studies’ primary endpoints were the amount of time before patients relapsed.
Results of SAkuraStar, which enrolled 95 patients, published in April in The Lancet Neurology showed that protocol-defined relapses occurred in 30% of patients on Enspryng and 50% of patients in the placebo arm. In SAkuraSky, which enrolled 83 patients, relapses occurred in 20% of those receiving Enspryng and 43% of those receiving placebo, according to results published in The New England Journal of Medicine in November 2019.
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