Spinraza (generic name nusinersen, and previously known as IONIS-SMN Rx) is an antisense oligonucleotide (ASO) that consists of small pieces of synthetic material that bind ribonucleic acid (RNA). The therapy, which was developed to treat infants and children with spinal muscular atrophy, targets the SMN2 gene and converts it to a SMN1 gene, which then binds to the RNA template made by SMN2 and enhances the inclusion of exon 7 into the SMN protein, increasing its production.1

Biogen and Ionis Pharmaceuticals have achieved several key developmental goals for the therapy, bringing nusinersen closer to regulatory approval. Both U.S. and European regulatory agencies have designated nusinersen an Orphan Drug for the treatment of patients with spinal muscular atrophy (SMA). The FDA also awarded nusinersen Fast Track Status for approval and Accelerated Assessment in the EU.2,3

The FDA announced approval of Spinraza for the treatment of SMA in both infants and adults on December 23, 2016.6

Recent findings for nusinersen

On Aug. 1, 2016, Biogen and Ionis announced that nusinersen met the primary endpoint pre-specified for the companies’ ENDEAR clinical trial. Interim analysis showed that infants taking nusinersen experienced a statistically significant improvement in the achievement of motor milestones compared to those who did not receive treatment. As a result of the study’s positive results, all participants who finished the trials (ENDEAR and CHERISH) were able to enroll in extension studies, providing them with extended use of the experimental therapy. This open-label extension (SHINE) has already begun, and is continuing to evaluate the long-term safety and tolerability of nusinersen.3

Clinical trials for nusinersen

Nusinersen was developed to treat infants and children with SMA. The drug is currently in Phase 3 clinical trials, which is typically the final stage of development before an experimental therapy is eligible for approval by regulatory bodies.

Recent and current trials for Nusinersen include:

  • The ENDEAR trial (NCT02193074), a Phase 3 randomized, double-blind, sham-procedure controlled, 13-month study in 122 infants diagnosed with SMA, evaluating the efficacy and safety of a 12 mg dose of nusinersen.
  • The CHERISH trial (NCT02292537), a Phase 3 randomized, double-blind, sham-procedure controlled, 15-month study in 126 children, non-ambulatory with later-onset SMA, between the ages of 2 and 12 years old. It also evaluates the efficacy and safety of the same dose of nusinersen.
  • The EMBRACE trial (NCT02462759) is a Phase 2 double-blind study evaluating the safety and pharmacokinetics of nusinersen.

Following positive results announced in early August, both the ENDEAR and EMBRACE studies will close and study participants have the option of enrolling in the SHINE (NCT02594124) open-label extension study. This study will collect additional data on the long-term safety, tolerability and efficacy of repeated doses of nusinersen in these patients.

The CHERISH study has completed enrollment and findings are planned to be reported in 2017.4

Next steps for nusinersen

Biogen and Ionis announced acceptance of a New Drug Application (NDA) and priority review for nusinersen by the FDA in late 2016. A Marketing Authorization Application (MAA) has been validated by the EMA (European Medicines Agency).5

Additional information on current and past studies for nusinersen is available at clinicaltrials.gov.

Read the latest nusinersen news on SMA News Today.

Follow the latest developments for all experimental Spinal Muscular Atrophy treatments on the SMA Therapy Tracker.

SMA News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.


  1. http://www.smatrust.org/research/funding-world-class-sma-research/therapy-pipeline/ionis-smnrx/
  2. http://www.ionispharma.com/pipeline/
  3. http://newsroom.biogen.com/press-release/corporate/biogen-and-ionis-pharmaceuticals-announce-spinraza-nusinersen-meets-primary-
  4. http://www.smatrust.org/sma-community-statement-ionis-biogen/
  5. http://newsroom.biogen.com/press-release/corporate/biogens-regulatory-applications-nusinersen-treatment-spinal-muscular-atrophy
  6. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm534611.htm