US regulators have approved Roche's Enspryng (satralizumab-mwge) as the first and only subcutaneous treatment for adults living with the rare autoimmune disorder anti-aquaporin-4 (AQP4) antibody positive neuromyelitis optica spectrum disorder (NMOSD).
The condition is often misdiagnosed as multiple sclerosis, as it primarily damages the optic nerve(s) and spinal cord, causing blindness, muscle weakness and paralysis.
Enspryng is a humanised monoclonal antibody designed to target and inhibit interleukin-6 (IL-6) receptor activity, which is believed to play a key role in the inflammation associated with NMOSD.
The treatment was designed by Chugai, a member of the Roche group, using novel recycling antibody technology, which compared to conventional technology, allows for longer duration of antibody circulation and subcutaneous dosing every four weeks.
Approval was based on data from the SAkuraStar and SAkuraSky studies, in which Enspryng demonstrated robust and sustained efficacy and a favourable safety profile in adults with AQP4 antibody positive NMOSD.
In the SAkuraStar monotherapy study’s AQP4 antibody positive subgroup, 76.5% of Enspryng-treated patients were relapse-free at 96 weeks, compared to 41.1% with placebo. In the SAkuraSky study, which evaluated the treatment when used concurrently with baseline IST, 91.1% were relapse-free at 96 weeks, compared to 56.8% with placebo.
“For people with NMOSD, relapses can cause devastating, irreversible and disabling neurological effects,” said Professor Jeffrey Bennett, University of Colorado Neurology & Ophthalmology, and investigator for the Enspryng pivotal clinical trials.
“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.”