The objective of this report was to identify the level of evidence for use of nusinersen to treat spinal muscular atrophy (SMA) and review clinical considerations regarding use. The author panel systematically reviewed nusinersen clinical trials for patients with SMA and assigned level of evidence statements based on the American Academy of Neurology’s 2017 therapeutic classification of evidence scheme. Safety information, regulatory decisions, and clinical context were also reviewed. Four published clinical trials were identified, 3 of which were rated above Class IV evidence. Evidence of efficacy is currently highest for treatment of infantile- and childhood-onset SMA in the early and middle symptomatic phases. While approved indications for nusinersen use in North America and Europe are broad, payer coverage for populations outside those in clinical trials remain variable. Evidence, availability, cost, and patient preferences all influence decision-making regarding nusinersen use.
