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Adverse event (AE): An adverse event is any undesirable experience associated with the use of a medical product.

Atrophy (of skeletal muscle): A reduction in the size of muscle fibers, the strength of the muscle, and the resistance to fatigue. 

Autosomal recessive disorder: An autosomal recessive disorder such as spinal muscular atrophy (SMA) requires 2 copies of an abnormal gene, 1 copy from each parent, to be present in order for the disease or trait to develop.

Carrier: Someone who carries and is capable of passing on a genetic mutation associated with a disease or trait, though he/she may not display symptoms. Two carriers may produce a child with the disease.

Central nervous system (CNS): The CNS is the part of the nervous system, consisting of the brain and spinal cord, which is affected by SMA. Intrathecal injection delivers SPINRAZA directly to CNS.

ENDEAR: A 13-month, phase 3 clinical study with 2:1 randomization, meaning two-thirds of individuals received SPINRAZA and one-third were untreated. The study measured the proportion of motor milestone responders in infants treated with SPINRAZA vs untreated infants, and was ended early as a result of significant improvements seen in a planned interim analysis at day 183 for those who had been on treatment for at least 6 months.

Family Access Manager (FAM): An advocate for individuals taking SPINRAZA and their families who is dedicated to minimizing nonmedical barriers to access and providing support throughout the treatment journey. He/she works closely with families to help gain access to therapy by navigating site-of-care logistics, payer policy procedure, and providing other support services.

Hammersmith Infant Neurological Examination (HINE): An assessment tool that uses a point system to measure progress in various categories of motor milestones for infants between 2 and 24 months of age. The examination includes evaluations of posture, movement, tone, and reflexes. An overall score is assigned to each infant based on his/her milestone development. Learn more about the HINE.

Interim analysis: An analysis of data that is taken before the scheduled completion of a clinical study. Most clinical studies include a plan for ending early if the interim results indicate a treatment is particularly beneficial or harmful compared to an untreated group.

Intrathecal injection: Delivers medication through the lower back via a lumbar puncture and directly to the CNS. Sedation may be used depending on the condition of the individual.

Lead Case Manager (LCM): LCMs are committed to helping individuals taking SPINRAZA and their families make informed decisions about care. They can provide insights into insurance benefits for SPINRAZA and help to find the most affordable way to start and stay on treatment as prescribed.

Loading dose: An initial dose or series of doses given to rapidly achieve a therapeutic concentration of medication in the body.

Lumbar puncture: During a lumbar puncture, a needle is inserted into the spinal canal in the lower back, which allows for intrathecal injection of SPINRAZA.

Maintenance dose: A smaller or less frequent dose given after the initial loading dose period to maintain the appropriate levels of medication in the body.

Motor milestone responder: Measured according to Section 2 of the HINE, a responder is defined as anyone with at least a 2-point increase (or maximum score of 4) in their ability to kick, or at least a 1-point increase in the categories of head control, rolling, sitting, crawling, standing, or walking. Individuals must also show improvements in more categories of motor milestones than worsening.

Motor neuron: Motor neurons are specialized nerve cells in the brain and spinal cord that control muscle movement.

Open-label: A type of clinical study in which both patients and healthcare providers know what treatment is being given.

Scoliosis: Curvature of the spine, which is a common problem in individuals with spinal muscular atrophy.

SMA360°: Biogen’s SMA360° support program provides certain services that address nonmedical barriers to access.*  These include logistical assistance, product education, insurance benefits investigation, and financial assistance. A complete list of SMA360° offerings can be found here.

Spinal muscular atrophy (SMA): A rare genetic disease in which a lack of survival motor neuron (SMN) protein affects the part of the nervous system that controls motor function.

Survival motor neuron 1 (SMN1) gene: The SMN1 gene produces SMN protein, which is critical to the health of specialized nerve cells in the spinal cord called motor neurons. Without SMN protein, motor neurons die and nerve impulses are not passed between the brain and the muscles, leading to muscle weakness and impaired motor function in SMA.

Survival motor neuron 2 (SMN2) gene: A closely related “backup” gene to the SMN1 gene, which is missing or mutated in SMA. On its own, SMN2 produces an insufficient amount of the SMN protein needed for normal motor function and development. 

Survival motor neuron (SMN) protein: SMN protein is responsible for the health and normal function of motor neurons in the CNS. SMN protein is found throughout the body, with high levels in the spinal cord. Insufficient levels of SMN protein are the underlying cause of motor neuron loss in SMA.

*SMA360° services from Biogen are available only to those who have been prescribed SPINRAZA. SMA360° is intended for US residents only.


Increased risk of bleeding complications has been observed after administration of similar medicines. Your healthcare provider should 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, has been observed after administration of similar medicines. Your healthcare provider should perform urine testing before you start treatment with SPINRAZA and before each dose to monitor for signs of this risk.

The most common side effects of SPINRAZA include lower and upper respiratory infections, constipation, headache, back pain, and 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.

This information is not intended to replace discussions with your healthcare provider.

Please see full Prescribing Information for additional Important Safety Information.

As a courtesy, our full Prescribing Information is also available en Español. For prescribing decisions, please refer to official approved labeling.


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