ABOUT SMA / WHAT IS SMA?

For patients with SMA,
disease progression is lifelong1-3

Spinal muscular atrophy (SMA) is a progressive neuromuscular disease4

SMA is defined as a neuromuscular disease of the central nervous system (CNS) that results in the deterioration of motor function and strength over time, due to motor neuron loss, although the rate and severity vary. Watch to learn more about the causes and symptoms of SMA.3,5,6

Mechanism of disease

Watch the video to learn about the clinical manifestations and cause of SMA.

The broad range of SMA symptoms includes7:

// Weakness that is usually symmetrical and more proximal than distal

// Absent or diminished tendon reflexes

// Difficulty or inability to walk

// Respiratory issues that may require tracheostomy or ventilation 

SMA is caused by a lack of functional survival motor neuron (SMN) protein5

Two nearly identical genes produce SMN protein4

People with SMA have a homozygous deletion of their SMN1 gene, and rely on the SMN2 gene to produce functional SMN protein. However, SMN2 can only produce about 10% of the protein the motor neurons need to power muscles, resulting in the progressive loss of strength and motor function that all patients with SMA experience.4,5

Why it’s important to consider treating SMA as soon as possible

Motor function loss may be permanent and unpredictable1,6,9

Because the rate of motor function loss is different for every patient, there is no way to predict when motor function loss will occur or how severe it will be.
Adults with later-onset SMA are at risk for progression1-3,9

Despite apparent plateaus, untreated adults with later-onset SMA will continue to lose muscle strength or function over time.

SMA, spinal muscular atrophy; SMN, survival motor neuron; SMN1, survival motor neuron 1 gene; SMN2, survival motor neuron 2 gene.
Genetic testing can confirm an SMA diagnosis or SMA carrier status.10
Learn about genetic testing offered at no charge to patients

Treatment of SMA involves many different types
of healthcare specialists

LEARN ABOUT MULTIDISCIPLINARY CARE
LEARN ABOUT AN SMA TREATMENT

INDICATION

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

IMPORTANT SAFETY INFORMATION

Coagulation abnormalities and thrombocytopenia, including acute severe thrombocytopenia, have been observed after administration of some antisense oligonucleotides. Patients may be at increased risk of bleeding complications.

In the sham-controlled studies for patients with infantile-onset and later-onset SMA, 24 of 146 SPINRAZA-treated patients (16%) with high, normal, or unknown platelet count at baseline developed a platelet level below the lower limit of normal, compared to 10 of 72 sham-controlled patients (14%). Two SPINRAZA-treated patients developed platelet counts <50,000 cells per microliter, with the lowest level of 10,000 cells per microliter recorded on study day 28.

Renal toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. SPINRAZA is present in and excreted by the kidney. In the sham-controlled studies for patients with infantile-onset and later-onset SMA, 71 of 123 SPINRAZA-treated patients (58%) had elevated urine protein, compared to 22 of 65 sham-controlled patients (34%).

Laboratory testing and monitoring to assess safety should be conducted. Perform a platelet count, coagulation laboratory testing, and quantitative spot urine protein testing at baseline and prior to each dose of SPINRAZA and as clinically needed.

Severe hyponatremia was reported in an infant treated with SPINRAZA requiring salt supplementation for 14 months.

Cases of rash were reported in patients treated with SPINRAZA.

SPINRAZA may cause a reduction in growth as measured by height when administered to infants, as suggested by observations from the controlled study. It is unknown whether any effect of SPINRAZA on growth would be reversible with cessation of treatment.

The most common adverse reactions (≥20% of SPINRAZA-treated patients and ≥5% more frequently than in control patients) that occurred in the infantile-onset controlled study were lower respiratory infection and constipation. Serious adverse reactions of atelectasis were more frequent in SPINRAZA-treated patients (18%) than in control patients (10%). Because patients in this controlled study were infants, adverse reactions that are verbally reported could not be assessed. The most common adverse reactions that occurred in the later-onset controlled study were pyrexia, headache, vomiting, and back pain. Post-lumbar puncture syndrome has also been observed after the administration of SPINRAZA.

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.

References

1. Wadman RI, Wijngaarde CA, Stam M, et al. Muscle strength and motor function throughout life in a cross-sectional cohort of 180 patients with spinal muscular atrophy types 1c–4. Eur J Neurol. 2018;25(3):512-518. 2. Montes J, McDermott MP, Mirek E, et al. Ambulatory function in spinal muscular atrophy: age-related patterns of progression. PLoS One. 2018;13(6):e0199657. 3. Werlauff U, Vissing J, Steffensen BF. Change in muscle strength over time in spinal muscular atrophy types II and III. A long-term follow-up study. Neuromuscul Disord. 2012;22(12):1069-1074. 4. Lunn MR, Wang CH. Spinal muscular atrophy. Lancet. 2008;371(9630):2120-2133. 5. National Institutes of Health, National Library of Medicine. MedlinePlus: SMN1 gene. Updated August 18, 2020. Accessed March 7, 2023. https://ghr.nlm.nih.gov/gene/ SMN1 6. Deymeer F, Serdaroglu P, Parman Y, Poda M. Natural history of SMA IIIb: muscle strength decreases in a predictable sequence and magnitude. Neurology. 2008;71:644-649. 7. Wang CH, Finkel RS, Bertini ES, et al. Consensus statement for standard of care in spinal muscular atrophy. J Child Neurol. 2007;22(8):1027-1049. 8. McGovern VL, Iyer CC, Arnold WD, et al. SMN expression is required in motor neurons to rescue electrophysiological deficits in the SMNΔ7 mouse model of SMA. Hum Mol Genet. 2015;24(19):5524-5541. 9. Zerres K, Rudnik-Schöneborn S, Forrest E, Lusakowska A, Borkowska J, Hausmanowa- Petrusewicz I. A collaborative study on the natural history of childhood and juvenile onset proximal spinal muscular atrophy (type II and III SMA): 569 patients. J Neurol Sci. 1997;146(1):67-72. 10. D’Amico A, Mercuri E, Tiziano FD, Bertini E. Spinal muscular atrophy. Orphanet J Rare Dis. 2011;6:71.

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