As you have conversations with your family, friends, or healthcare providers, you can use this glossary to better understand some of the medical terms

age 4

Later-onset (Type 2) SMA
treated with SPINRAZA

Spinraza reference glossary

Adverse event (AE): Any undesirable experience associated with the use of a medical product.

Ambulatory: An individual who can walk without assistance.

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: A 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.

Controlled study: This term is often used to describe a study that compares the effectiveness and safety of a medication in one group of patients with a second group of patients who receive a placebo.

CS2/CS12: An open-label study evaluating SPINRAZA in ambulatory and nonambulatory individuals aged 2-15 years with later-onset (Types 2 and 3) SMA.

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.

Family Access Manager (FAM): A Biogen 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.

Hammersmith Functional Motor Scale-Expanded (HFMSE): Assesses motor function of individuals with later-onset SMA. It measures 33 items grouped into 7 categories, such as standing, stepping, and walking.

Infantile-onset SMA: Infants who started to experience symptoms of SMA at 6 months of age or younger. Typically classified as Type 1 SMA.

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 with an untreated group.

Intrathecal injection: An injection into the cerebrospinal fluid (the fluid in the spine) This delivers medication directly to the CNS. Sedation may be used depending on the condition of the individual.

Lead Case Manager (LCM): LCMs from Biogen 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 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 Hammersmith Infant Neurological Examination, 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: Specialized nerve cells in the brain and spinal cord that control muscle movement.

Nonambulatory: An individual who is not capable of walking due to severe contractures in the lower limbs.

NURTURE: An open-label study of presymptomatic infants aged 8 to 42 days who were genetically diagnosed with SMA before the onset of symptoms.

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

Prior authorization (also called “preauthorization”): The requirement by a health insurance plan that they must decide whether a treatment or medication is medically necessary before they will provide coverage according to the terms of the plan.

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

Six-minute walk test (6MWT): Measures the distance an individual can walk in 6 minutes. Individuals are instructed to walk as far as possible along a 25-meter course and return in the opposite direction. The course is repeated as often as possible for 6 minutes.

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 for eligible individuals. 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. In individuals with SMA, a mutated or deleted SMN1 gene does not produce enough SMN protein to maintain the survival of motor neurons.

Survival motor neuron 2 (SMN2) gene: A closely related “backup” gene that is not considered to be affected 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: 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.

Upper Limb Module (ULM): An assessment that includes 9 tasks reflecting activities of daily living and can typically be performed in a brief amount of time (5 to 10 minutes) using common equipment. Activities include using a pencil, picking up a coin and placing it in a cup, pressing a button to turn on a lamp, lifting a beverage can to drink, removing the lid from a plastic container, and moving a weight from circle to circle on preprinted paper.

*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 respiratory infection, fever, constipation, headache, vomiting, 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.

Before taking SPINRAZA, tell your healthcare provider if you are pregnant or plan to become pregnant.

Please see full Prescribing Information.

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

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


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