One of the latest breakthroughs in care for patients with spinal muscular atrophy (SMA) is the FDA approval of a new medicine called nusinersen (brand name Spinraza) for the treatment of SMA in children and adults.

How does nusinersen work?

Nusinersen is a medication that is used to increase production of the survival of motor neuron (SMN) protein. While individuals with SMA do not have functional copies of SMN1, they typically have multiple copies of the SMN2 gene. The SMN2 gene is not as functional as SMN1, and makes a much smaller amount of functioning protein.

Nusinersen alters how SMN2 is processed, increasing the amount of functional protein produced from this gene. Because the primary site of injury is in the motor neurons in the spinal cord, the medication is injected into the spinal fluid to specifically target the cells that are most affected.

Who is a candidate for nusinersen?

Your child’s doctor will determine if your child is a candidate for the drug based on genetic factors, disease type, and symptoms. Currently, nusinersen is approved for use in all patients who are confirmed to have the SMN gene mutation that causes the disease.

How is nusinersen given?

Nusinersen is injected directly into the fluid surrounding the spine using a needle. This procedure is called a lumbar puncture.

During a lumbar puncture, it is very important for your child to remain still. Many older children and teens are able to have this procedure performed without sedation, with only local anesthetics, or numbing medications. Some children will need sedation to help them stay calm and still.

At Children’s Hospital of Philadelphia, our expert pediatric anesthesiologists will work closely with the rest of the team to provide the safest possible care and make sure your child has the breathing support they need when under sedation. For individuals with severe scoliosis or prior spinal fusion, interventional radiology may be necessary to provide imaging guidance.

Depending on the individual needs of the child, this procedure can be done either in a regular procedure room, a sedation room, an operating room, or an interventional radiology suite. In the first two months, your child will receive four doses. After that, you’ll return once every four months for maintenance doses. Patients typically receive the drug during an outpatient visit. While the procedure time is short (typically around 15 minutes), the visit can last several hours, as monitoring labs are checked prior to the injection, and patients are observed for a minimum of one hour after the procedure is completed.

Our dedicated child life specialists are also available to work with your child and provide age-appropriate and therapeutic activities to make them feel comfortable and familiar with the procedure.

Outcomes of patients taking nusinersen

Early results of SMA treatment with Spinraza are promising. Clinical trials have shown some patients experience improvement in motor skills. Many others will stabilize and not experience any further loss or deterioration of skills. Research trials show that the earlier patients start the medication, the better the results.

Read more about other therapies currently available for treatment of children with SMA.