Health Canada approves Enspryng (satralizumab) for neuromyelitis optica spectrum disorder

Health Canada has approved Enspryng (satralizumab), the second disease modifying therapy available for adults and young people from 12 years of age, living with neuromyelitis optica spectrum disorder (NMOSD) who are aquaporin-4 antibody (AQP4-IgG) seropositive. Health Canada’s approval of Enspryng, marketed by Hoffman-La Roche, is based on results from two pivotal phase three studies, SAkuraSky and SAkuraStar.

Enspryng (satralizumab) is a humanized monoclonal antibody that is self-administered subcutaneously (under the skin) once every four weeks. Enspryng targets the interleukin-6 (IL-6) receptor, which is believed to play a key role in the inflammation that occurs NMOSD and works by preventing relapses of NMOSD for aquaporin-4 antibody (AQP4-IgG) seropositive patients.

Clinical Trials

SAkuraSky was a randomized, multicenter, double-blind, placebo-controlled clinical trial to evaluate the safety and efficacy of Enspryng in combination with a baseline immunosuppressant therapy (corticosteroids, azathioprine, or mycophenolate mofetil). The primary endpoint of SAkuraSky was time to first relapse, and included 83 patients, 55 of whom were AQP4-IgG seropositive. Participants received the first 3 single doses of Enspryng 120 mg or placebo by injection under the skin (subcutaneous) every 2 weeks for the first 4 weeks, and then once every 4 weeks thereafter. In total, 41 patients were randomized to receive Enspryng, and 42 were randomized to receive placebo. The risk of relapse was reduced by 79% with Enspryng, compared to placebo (in combination with baseline immunosuppressant therapy) in participants who were AQP4-IgG seropositive.

SAkuraStar was a randomized, multicenter, double-blind, placebo-controlled clinical trial to evaluate the safety and efficacy of ENSPRYNG monotherapy compared to placebo. The primary endpoint of the SAkuraStar study was time to first relapse and included 95 adult participants of which 64 were AQP4-IgG seropositive. Participants received the first 3 single doses of ENSPRYNG 120 mg or placebo by injection under the skin every 2 weeks for the first 4 weeks and once every 4 weeks thereafter. A total of 63 patients were randomized to receive ENSPRYNG and 32 were randomized to receive placebo. The risk of relapse was reduced by 74% with ENSPRYNG monotherapy compared to placebo.

The MS Society will provide updates related to reimbursement as they become available. Individuals interested in treatment with Enspryng are encouraged to speak with their healthcare team.

Reference: Yamamura T, Kleiter I, Fujihara K, et al. Trial of Satralizumab in Neuromyelitis Optica Spectrum Disorder. N Engl J Med. 2019;381(22):2114-2124. doi:10.1056/NEJMoa1901747

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