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Antisense oligonucleotides (ASO) intrathecal injection (12 mg/5 mL, 28 mg/5 mL, 50 mg/5 mL)

Spinraza

Generic name: nusinersen

Last updated March 31, 2026 0 views Reviewed by Carmen Pope, Senior Medical Editor, B. Pharm
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What is Spinraza?

Spinraza is used to treat spinal muscular atrophy (SMA) in children and adults. It is administered via intrathecal injection (an injection into the spine) by a healthcare provider every 4 months after an initial dosing period.

SMA is an inherited muscle-weakening condition caused by mutations in the SMN1 gene, which normally produces a protein needed for healthy motor neurons. A backup gene (SMN2) also makes this protein, but it's usually defective because a critical part called "exon 7" gets skipped. Spinraza’s mechanism ensures the missing piece of information from exon 7 is included when SMN2 produces protein, resulting in a properly functioning protein that helps keep motor neurons healthy. It belongs to the drug class called antisense oligonucleotides.

Spinraza (nusinersen) gained FDA approval on December 23, 2016. There is no generic.

  • Spinraza was the first drug to be approved by the FDA for SMA.

How is Spinraza administered?

Spinraza is administered by a qualified healthcare professional in a treatment center.

  • Spinraza is injected into the fluid of the spine (intrathecal injection) over 1 to 3 minutes.

Before you start treatment with Spinraza and before each dose, your doctor will order blood and urine testing to monitor for the potential risks of bleeding complications or kidney damage.

Before receiving

Before you receive Spinraza, tell your healthcare provider about all of your medical conditions, including if you:

  • have a bleeding disorder
  • have a kidney disorder
  • are pregnant or intend to become pregnant
  • are breastfeeding or intend to breastfeed.

Pregnancy

Spinraza may harm an unborn baby. You should not become pregnant while receiving Spinraza. Tell your doctor immediately if you become pregnant while receiving Spinraza.

Breastfeeding

There is no data about the presence of Spinraza in human milk. Talk to your doctor about the best way to feed your baby while receiving treatment with Spinraza.

Side effects

The most common side effects of Spinraza are:

  • Lower respiratory tract infections (such as a cold or the flu)
  • Constipation
  • Fever
  • Headache
  • Vomiting
  • Back pain
  • Post-lumbar puncture syndrome.

Serious side effects and warnings

Spinraza may cause the following serious side effects:

  • Increased risk of bleeding. Complications linked to an increased risk of bleeding have been observed after administration of similar medicines. Your healthcare provider will perform blood tests before you start treatment with Spinraza and before each dose to monitor for signs of these risks. Seek medical attention if unexpected bleeding occurs.
  • Increased risk of kidney damage, including potentially fatal acute inflammation of the kidney. An increased risk of kidney damage has been observed after administration of similar medicines. Your healthcare provider will perform urine testing before you start treatment with Spinraza and before each dose to monitor for signs of this risk.

These are not all of the possible side effects of Spinraza. Call your healthcare provider for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Dosing information

Recommended Spinraza dosage for SMA is one of two options:

Low Dose Regimen (12 mg):

  • 12 mg loading dose every 14 days for three doses; then a fourth 12 mg loading dose 30 days after the third dose
  • then a 12 mg maintenance dose once every 4 months (3 times per year) thereafter.

High Dose Regimen (50mg):

  • 50 mg loading dose followed by a second 50 mg loading dose 14 days later
  • then a 28 mg maintenance dose once every 4 months (3 times per year) thereafter

Before administering

  • Allow Spinraza to warm up to room temperature before administering.
  • Administer within 4 hours of removal from the vial.
  • Prior to administration, remove 5 mL of cerebrospinal fluid.
  • Administer as an intrathecal bolus injection over 1 to 3 minutes.
  • See the full prescribing information for further dosing information.

Spinraza injection:

  • 12 mg/5 mL (2.4 mg/mL) in a single-dose vial
  • 28 mg/5 mL (5.6 mg/mL) in a single-dose vial
  • 50 mg/5 mL (10 mg/mL) in a single-dose vial

What other drugs will affect Spinraza?

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Storage

Store Spinraza in a refrigerator between 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Do not freeze.

  • Protect from light and keep in the original carton until time of use.
  • If no refrigeration is available, Spinraza may be stored in its original carton, protected from light at or below 30°C (86°F) for up to 14 days.
  • Prior to administration, unopened vials of Spinraza can be removed from and returned to the refrigerator, if necessary. If removed from the original carton, the total combined time out of refrigeration should not exceed 30 hours at a temperature that does not exceed 25°C (77°F).

Keep out of reach of children.

What are the ingredients in Spinraza?

Active ingredient: nusinersen 12 mg

Inactive ingredients: monobasic dihydrate sodium phosphate, dibasic anhydrous sodium phosphate, sodium chloride, potassium chloride, calcium chloride, magnesium chloride, water.

Supplied as a 12 mg/5 mL (2.4 mg/mL) solution in a single-dose glass vial, free from preservatives.

Spinraza is manufactured by Biogen, located in Cambridge, MA.

Common questions about Spinraza

What is Spinraza's mechanism of action?
The Spinraza mechanism of action involves altering the splicing of the SMN2 gene to increase the levels of a more functional SMN protein. Spinraza is used to treat spinal muscular atrophy (SMA), a decline in muscle strength over time, in adults and children. People with SMA have a mutated SMN1 gene and can’t generate enough SMN protein needed for muscle development and strength.
Zolgensma vs Spinraza: What are the key differences?
Zolgensma (onasemnogene abeparvovec-xioi) and Spinraza (nusinersen sodium) are both treatments for people with spinal muscular atrophy (SMA). There are a number of key differences between the two treatments, including: Which patients with SMA they are approved for use in How often they are administered The type of treatments they are How they work How well they work Continue reading
Evrysdi vs Spinraza: How do they compare?
Evrysdi (risdiplam) and Spinraza (nusinersen) work in different ways to increase the level of functional SMN (survival of motor neuron) protein in people with spinal muscular atrophy (SMA). A key difference between the two drugs is that Evrysdi is taken orally, whereas Spinraza needs to be given via intrathecal injection. Continue reading
How is Spinraza administered?
Spinraza (nusinersen) is a prescription injection administered into the spine to treat spinal muscular atrophy (SMA), a genetic disease affecting muscle-controlling nerve cells, in adults and children. Continue reading

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
General medicine information Consumer-friendly language Source: Drugs.com

Content is provided for education and is not medical advice. See our medical disclaimer. Source page medically reviewed by Carmen Pope, Senior Medical Editor, B. Pharm on March 31, 2026.