Last reviewed 2026-04-20 · How we verify

Spinraza (NUSINERSEN)

Spinraza works by binding to a specific genetic sequence to increase production of a protein that helps maintain muscle function.

Spinraza (Nusinersen) is an antisense oligonucleotide developed by Biogen Idec, approved by the FDA in 2016 for the treatment of spinal muscular atrophy. It is a small molecule modality that works by modifying the production of a specific protein responsible for the disease. Spinraza is a patented medication with no generic manufacturers available. It is used to treat a rare genetic disorder that affects muscle strength and movement. Key safety considerations include potential risks of liver damage and bleeding.

At a glance

Mechanism of action

SPINRAZA is an antisense oligonucleotide (ASO) designed to treat SMA caused by mutations in chromosome 5q that lead to SMN protein deficiency. Using in vitro assays and studies in transgenic animal models of SMA, SPINRAZA was shown to increase exon inclusion in SMN2 messenger ribonucleic acid (mRNA) transcripts and production of full-length SMN protein.

Approved indications

• Spinal muscular atrophy

Common side effects

• Lower respiratory infection
• Constipation
• Pyrexia
• Headache
• Vomiting
• Back pain
• Atelectasis
• Urinary tract infection
• Upper respiratory tract congestion
• Ear infection
• Flatulence
• Decreased weight

Key clinical trials

• A Study to Evaluate How Apitegromab Works in Subjects Who Are Less Than 2 Years Old and Have Spinal Muscular Atrophy (PHASE2)
• A Study to Find Out How Nusinersen is Processed in the Body When Given Through the ThecaFlex DRx™ System in Adult and Pediatric Participants With Spinal Muscular Atrophy (PIERRE-PK) (PHASE1)
• A Study to Learn How Nusinersen (Spinraza) Affects Participants With Spinal Muscular Atrophy (SMA) Who Took it Before or During Pregnancy And About The Health of Their Babies
• Study of an Intrathecal Port and Catheter System for Subjects With Spinal Muscular Atrophy (NA)
• Motor Unit Number Estimation (MUNE) in Adults With Spinal Muscular Atrophy (SMA)
• A Study to Learn About the Long-Term Safety of Higher Doses of Nusinersen (BIIB058) Given as Injections to Participants With Spinal Muscular Atrophy (SMA) Who Took Part in an Earlier Nusinersen Trial (ONWARD) (PHASE3)
• Characterizing Perceived Physical Fatigability in Nusinersen-treated SMA
• Characterization of New Phenotypes of Patients With Spinal Muscular Atrophy Treated With SMN Restoring Therapy (NA)

Patents

Primary sources

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