Nusinersen: A Treatment for Spinal Muscular Atrophy.

OBJECTIVE: To review the efficacy and safety of nusinersen (Spinraza) in the treatment of spinal muscular atrophy (SMA).

DATA SOURCES: An English-language literature search of PubMed and MEDLINE (1946 to June 2018) was performed using the terms nusinersen, ISIS-SMN (Rx), and spinal muscular atrophy. Manufacturer prescribing information, abstracts, article bibliographies, and clinicaltrials.gov data were incorporated for additional materials.

STUDY SELECTION/DATA EXTRACTION: All clinical trials of nusinersen were identified and analyzed in the review.

DATA SYNTHESIS: Nusinersen is the first drug therapy approved for the treatment of SMA. It is a novel modified antisense oligonucleotide designed to treat SMA caused by mutations in chromosome 5q that lead to survival motor neuron protein deficiency. Nusinersen has been studied for safety, pharmacokinetics, and efficacy in both open-label and randomized controlled trials. The studies show improvement in motor function across SMA of all types. The most common adverse effects were respiratory tract infections, headache, back pain, constipation, and post-lumbar puncture syndrome. Relevance to Patient Care and Clinical Practice: Based on phase III trial data, nusinersen produced positive changes in the clinical course of patients with SMA. The acquisition and administration of nusinersen present a number of challenges in clinical practice. Its intrathecal delivery and costly price tag must be recognized.

CONCLUSION: Nusinersen is safe and effective in patients with SMA. It was well tolerated across all studied age groups.