By Counterforce Health Team —

A Groundbreaking Therapy for Spinal Muscular Atrophy: Spinraza (Nusinersen)

Spinal muscular atrophy (SMA) is a rare genetic disorder that affects the nerves controlling voluntary muscles. It leads to muscle weakness and atrophy, which can affect movement, breathing, and swallowing.

Spinraza® (nusinersen) is a disease-modifying therapy that has transformed the treatment landscape for SMA. It was the first FDA-approved therapy for SMA, offering hope to patients and families affected by this challenging condition.

What Is Spinraza Used For?

Spinraza is approved for treating children and adults with spinal muscular atrophy, regardless of age or disease stage. It can:

  • Improve muscle function and strength
  • Help children achieve motor milestones (like sitting, standing, or walking)
  • Support breathing and swallowing function in affected individuals

By targeting the root cause of SMA, Spinraza addresses the underlying genetic problem rather than just the symptoms.

How Spinraza Works

Spinraza contains nusinersen, an antisense oligonucleotide. Its mechanism of action includes:

  1. Targeting the SMN2 gene: People with SMA have mutations in the SMN1 gene, which leads to insufficient production of survival motor neuron (SMN) protein.
  2. Increasing SMN protein production: Spinraza modifies SMN2 gene expression so that more functional SMN protein is produced.
  3. Supporting motor neurons: Increased SMN protein helps maintain the health of motor neurons, slowing disease progression and improving muscle function.

How Spinraza Is Administered

  • Form: Intrathecal injection (directly into the cerebrospinal fluid around the spinal cord)
  • Dosing schedule:
    • Loading doses: Typically 4 doses over the first 2 months
    • Maintenance doses: Once every 4 months thereafter
  • Setting: Administered by a trained healthcare professional in a clinic or hospital

Because Spinraza is delivered intrathecally, it bypasses the bloodstream to directly reach the nervous system.

Benefits of Spinraza

  • Disease-modifying treatment: Slows SMA progression and improves motor function
  • Effective across age groups: Works for infants, children, and adults
  • Proven clinical outcomes: Many patients achieve milestones not typically seen without treatment
  • Improved quality of life: Supports independence and functional abilities

Possible Side Effects

Common side effects include:

  • Headache
  • Back pain
  • Nausea
  • Vomiting
  • Fever or respiratory infections

Less common but serious side effects may include:

  • Low platelet counts
  • Kidney problems
  • Injection-related complications

Regular monitoring of blood counts, kidney function, and neurological status is recommended during treatment.

Precautions and Drug Interactions

  • Spinraza should be administered by a trained healthcare professional due to its intrathecal delivery.
  • Patients with bleeding disorders or severe spinal deformities should be carefully evaluated before administration.
  • There are no known significant drug interactions, but all medications should be reviewed with the healthcare provider.

Monitoring During Treatment

Healthcare providers typically monitor:

  • Platelet counts and kidney function before each dose
  • Neurological and motor function over time
  • Any adverse reactions to the injection

Close monitoring helps ensure the therapy is both safe and effective.

The Bottom Line

Spinraza (nusinersen) is a groundbreaking therapy for spinal muscular atrophy. By increasing the production of SMN protein, it targets the root cause of the disease and helps improve motor function, slow disease progression, and enhance quality of life for patients of all ages.

While administration requires careful monitoring and intrathecal injections, Spinraza represents a life-changing optionfor individuals and families affected by SMA.