Nusinersen

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 7 inclusion in SMN2 messenger ribonucleic acid (mRNA) transcripts and production of full-length SMN protein.

• SPINRAZA is indicated for the treatment of spinal muscular atrophy (SMA) in pediatric and adult patients.

• None. None.contraindicated

SPINRAZA is administered intrathecally ( 2.1 ) Recommended Dosage ( 2.1 ) The recommended dosage is one of two options: Low Dose Regimen: Administer one 12 mg loading dose every 14 days for three doses; then a fourth 12 mg loading dose 30 days after the third dose; then administer a 12 mg maintenance dose once every 4 months thereafter. High Dose Regimen: Administer one 50 mg loading dose followed by a second 50 mg loading dose 14 days later; then administer a 28 mg maintenance dose once every 4 months thereafter. Important Preparation and Administration Instructions ( 2.3 ) Allow to warm to room temperature prior to administration Administer within 4 hours of removal from vial Prior to administration, remove 5 mL of cerebrospinal fluid Administer as intrathecal bolus injection over 1 to 3 minutes Laboratory Testing and Monitoring to Assess Safety ( 2.4 ) At baseline and prior to each dose, obtain a platelet count, coagulation laboratory testing, and quantitative spot urine protein testing 2.1 Recommended Dosage SPINRAZA is administered intrathecally by, or under the direction of, healthcare professionals experienced in performing lumbar punctures. Two dosing regimen options for SPINRAZA, which consist of loading followed by maintenance dosages, are presented in Table 1 . Table 1: Recommended Dosage for SPINRAZA Loading Dosages Maintenance Dosage Low Dose Regimen (Low dose with four loading doses) Administer a total of four loading doses as follows: one 12 mg dose every 14 days for three doses, then a fourth 12 mg dose 30 days after the third dose.

Thrombocytopenia and Coagulation Abnormalities: Increased risk for bleeding complications; testing required at baseline and before each dose and as clinically needed ( 5.1 , 2.3 ) Renal Toxicity: Quantitative spot urine protein testing required at baseline and prior to each dose ( 5.2 , 2.3 ) 5.1 Thrombocytopenia and Coagulation Abnormalities Coagulation abnormalities and thrombocytopenia, including acute severe thrombocytopenia, have been observed after administration of some antisense oligonucleotides. In the sham-controlled studies for patients with infantile-onset (Study 1) and later-onset (Study 2) SMA who received Low Dose Regimen [see Clinical Studies ( 14.1 , 14.2 )] , 24 of 146 (16%) SPINRAZA-treated patients with high, normal, or unknown platelet count at baseline developed a platelet level below the lower limit of normal, compared to 10 of 72 (14%) sham-controlled patients. In Study 2, two SPINRAZA-treated patients developed platelet counts less than 50,000 cells per microliter, with a lowest level of 10,000 cells per microliter recorded on study day 28. In patients who received High Dose Regimen, decreases in platelet counts were also observed. Because of the risk of thrombocytopenia and coagulation abnormalities from SPINRAZA, patients may be at increased risk of bleeding complications. Perform a platelet count and coagulation laboratory testing at baseline and prior to each administration of SPINRAZA and as clinically needed.

The following serious adverse reactions are described in detail in other sections of the labeling: Thrombocytopenia and Coagulation Abnormalities [see Warnings and Precautions ( 5.1 )] Renal Toxicity [see Warnings and Precautions ( 5.2 )] The most common adverse reactions that occurred in at least 20% of SPINRAZA-treated patients who received Low Dose Regimen and occurred at least 5% more frequently than in control patients were: lower respiratory infection and constipation in patients with infantile-onset SMA ( 6.1 ) pyrexia, headache, vomiting, and back pain in patients with later-onset SMA ( 6.1 ) The most common adverse reactions in at least 10% of SPINRAZA-treated patients who received High Dose Regimen and occurred at least 5% more frequently than in historic matched sham-control were: pneumonia, COVID-19, pneumonia aspiration, and malnutrition in patients with infantile-onset SMA ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Biogen at 1-844-477-4672 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of SPINRAZA cannot be directly compared to rates in clinical trials of other drugs and may not reflect the rates observed in practice.

Pregnancy: Based on animal data, may cause fetal harm ( 8.1 ) 8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of SPINRAZA in pregnant women. When nusinersen was administered by subcutaneous injection to mice throughout pregnancy and lactation, developmental toxicity (long-term neurobehavioral impairment) was observed at all doses tested (see Data ) . In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. Data Animal Data When nusinersen (0, 3, 10, or 25 mg/kg) was administered subcutaneously to male and female mice every other day prior to and during mating and continuing in females throughout organogenesis, no adverse effects on embryofetal development were observed. Subcutaneous administration of nusinersen (0, 6, 12.6, or 25 mg/kg) to pregnant rabbits every other day throughout organogenesis produced no evidence of embryofetal developmental toxicity.

Metabolism

Absorption Intrathecal injection of SPINRAZA into the cerebrospinal fluid (CSF) allows nusinersen to be distributed from the CSF to the target central nervous system (CNS) tissues. Following intrathecal administration, trough plasma concentrations of nusinersen were relatively low, compared to the trough CSF concentration.

• Dec 23, 2016NDANDA209531Biogen Idec

1. 1Headache5277.0%
2. 2Post Lumbar Puncture Syndrome5116.8%
3. 3Pyrexia3995.3%
4. 4Procedural Pain3664.9%
5. 5Pneumonia3614.8%
6. 6Death3294.4%
7. 7Vomiting3024.0%
8. 8Asthenia2823.8%
9. 9Back Pain2463.3%
10. 10Scoliosis2243.0%
11. 11Fatigue2132.8%
12. 12Fall1712.3%
13. 13Malaise1712.3%
14. 14Nausea1622.2%
15. 15Nasopharyngitis1602.1%

The 10 most recently updated of 57 ClinicalTrials.gov registrations naming Nusinersen as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• A Study to Learn About the Effect of Higher Doses of Nusinersen (BIIB058) Given as Injections to Participants With Spinal Muscular Atrophy (SMA) Who Were Previously Treated With Risdiplam (ASCEND)
  Active not recruiting · Phase 3 · Interventional · 45 enrolled · Biogen
  NCT05067790updated 2026-05-22
• Characterizing Perceived Physical Fatigability in Nusinersen-treated SMA
  Recruiting · Observational · 45 enrolled · Columbia University
  NCT06955897updated 2026-05-14
• A Study to Evaluate How Apitegromab Works in Subjects Who Are Less Than 2 Years Old and Have Spinal Muscular Atrophy
  Recruiting · Phase 2 · Interventional · 52 enrolled · Scholar Rock, Inc.
  NCT07047144updated 2026-05-01
• Study of an Intrathecal Port and Catheter System for Subjects With Spinal Muscular Atrophy
  Recruiting · Interventional · 90 enrolled · Alcyone Therapeutics, Inc
  NCT05866419updated 2026-04-16
• 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)
  Recruiting · Phase 1 · Interventional · 58 enrolled · Biogen
  NCT06555419updated 2026-03-18
• 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
  Recruiting · Observational · 20 enrolled · Biogen
  NCT05789758updated 2026-03-09
• Motor Unit Number Estimation (MUNE) in Adults With Spinal Muscular Atrophy (SMA)
  Completed · Observational · 67 enrolled · Ohio State University
  NCT04139343updated 2026-02-23
• 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)
  Active not recruiting · Phase 3 · Interventional · 115 enrolled · Biogen
  NCT04729907updated 2026-02-18
• Characterization of New Phenotypes of Patients With Spinal Muscular Atrophy Treated With SMN Restoring Therapy
  Recruiting · Interventional · 60 enrolled · Hospices Civils de Lyon
  NCT06321965updated 2026-01-30
• A Study of Dosing Patterns and Costs in Patients With Spinal Muscular Atrophy Receiving Disease Modifying Therapies
  Completed · Observational · 4,114 enrolled · Novartis Pharmaceuticals
  NCT07378943updated 2026-01-30

Frequently asked questions

How does Nusinersen work?

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 7 inclusion in SMN2 messenger ribonucleic acid (mRNA) transcripts and production of full-length SMN protein.

What is Nusinersen used for?

According to FDA labeling, Nusinersen carries indications including: SPINRAZA is indicated for the treatment of spinal muscular atrophy (SMA) in pediatric and adult patients.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Nusinersen?

Nusinersen is classified as Other drugs for disorders of the musculo-skeletal system, Antisense Oligonucleotide, Survival Motor Neuron-2-directed RNA Interaction, Increased Protein Synthesis, Increased RNA Integrity.

What are the brand names for Nusinersen?

Nusinersen is marketed under brand names including Spinraza.

What are the contraindications for Nusinersen?

Nusinersen labeling lists contraindications including: None. None.. Always consult the full prescribing information and a clinician.