Generic name: nusinersen
Dosage form: intrathecal injection
Drug class: Miscellaneous uncategorized agents

Medically reviewed by Philip Thornton, DipPharm. Last updated on Mar 25, 2025.

What is Spinraza?

Spinraza is a type of medication called an antisense oligonucleotide. It is used to treat children and adults with spinal muscular atrophy (SMA), a type of motor neuron disease. It was the first drug to be approved by the US Food and Drug Administration (FDA) for this group of people.

SMA is an inherited disorder that causes skeletal muscle weakness and wasting, which worsens with age. SMA is most commonly caused by mutations in a gene called SMN1 (survival motor neuron 1), which leaves the body without enough functional SMN protein to keep motor neurons healthy and functioning.

A back-up gene called SMN2 also produces SMN protein, but only a small percentage of the protein produced by SMN2 functions properly. This is because when the protein is being made a portion of the gene called exon 7 tends to be skipped over, so the resulting protein isn't supplied with all of the right building blocks of information it needs to function properly.

Spinraza works by fixing the protein produced by SMN2 so that it functions properly. It does this by making sure that the missing piece of information from exon 7 is included.

Spinraza was approved by the FDA in 2016.

What is Spinraza used for?

Spinraza is a prescription medicine used to treat spinal muscular atrophy (SMA) in pediatric and adult patients.

Important information

Spinraza can cause serious side effects including:

• 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.

What should I tell my doctor before receiving Spinraza?

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

How should I receive Spinraza?

• Spinraza will be 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.
• You will receive 4 initial loading doses of Spinraza. The first 3 doses will be given at 14-day intervals and the 4th dose will be given 30 days after the 3rd dose.
• After your 4 loading doses, you will receive a maintenance dose of Spinraza every 4 months (3 times per year).

What happens if I miss a dose?

• If a loading dose of Spinraza is delayed or missed, administer it as soon as possible, with at least 14-days between doses and continue dosing as prescribed.
• If a maintenance dose of Spinraza is delayed or missed, administer it as soon as possible and continue dosing every 4 months.

Dosing information

• The recommended dosage of Spinraza is 12 mg (5 mL) per administration
• Spinraza treatment should be initiated with 4 loading doses. The first 3 loading doses should be administered at 14-day intervals. The 4th loading dose should be administered 30 days after the 3rd dose.
• A maintenance dose of Spinraza should be administered once every 4 months thereafter.
• See the full prescribing information for further dosing information.

What are the side effects of Spinraza?

Spinraza may cause serious side effects including:

• Thromocytopenia and coagulation abnormalities
• Renal toxicity

The most common side effects of Spinraza include:

• lower respiratory infection
• fever, constipation
• headache
• vomiting
• back pain
• post-lumbar puncture syndrome

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 FDA at 1-800-FDA-1088.

Related/similar drugs

Interactions

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

Pregnancy and breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before taking Spinraza. Spinraza may cause fetal harm according to the results of studies conducted in animals.

Tell your doctor if you are breastfeeding or plan to breastfeed before taking Spinraza. Talk to your doctor about the best way to feed your baby while receiving treatment with Spinraza.

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.
• Spinraza should be protected from light and kept 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

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

Spinraza is manufactured by Biogen, Cambridge, MA 02142.

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Further information

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