FDA Approves Nusinersen Drug To Treat Spinal Muscular Atrophy

Highlights

• Spinal Muscular Atrophy is a genetic disease that causes muscle weakness in children.
• FDA has recently approved Nusinersen drug for the treatment of Spinal Muscular Atrophy.
• Nusinersen drug is a SMN2 (Survival motor neuron) antisense oligonucleotide which is injected directly to the spinal cord for treatment.

The United States Food and Drug Administration has recently approved Nusinersen drug to treat Spinal Muscular Atrophy in children and adults. Spinal Muscular Atrophy (SMA) is a genetic disease which affect the nerve cells that controls voluntary muscle movements. It is marked by progressive muscle weakness.

Nusinersen (Spinraza) is the first and the only approved drug for the treatment of Spinal Muscular Atrophy in the United States. The drug was discovered and developed by Ionis and Biogen. It is licensed and marketed by Biogen for developing the drug.

Billy Dunn, M.D., director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, said, “There has been a long-standing need for a treatment for spinal muscular atrophy, the most common genetic cause of death in infants, and a disease that can affect people at any stage of life”

“As shown by our suggestion to the sponsor to analyze the results of the study earlier than planned, the FDA is committed to assisting with the development and approval of safe and effective drugs for rare diseases and we worked hard to review this application quickly; we could not be more pleased to have the first approved treatment for this debilitating disease.”

The drug has received FDA approval in fast track designation and priority review. Nusinersen has also received orphan drug designation which provides incentives to develop new drugs for rare diseases.

The importance of giving a fast track designation to a drug is mainly to provide important new drugs to the patient as early as possible. Priority review means FDA action has to be taken within 6 months of application.

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The drug efficacy was revealed in a clinical trial with 121 patients who have infantile-onset spinal muscular atrophy. These patients were diagnosed before 6 months of age and were found to be less than 7 months of age at the time of their first dose.

Patients randomly received nusinersen drug into the fluid surrounding the spinal cord. Control group patients did not receive injections (mock procedure). More than twice the number of patients received nusinersen when compared to those who underwent a mock procedure. The percentage of patients with improvement in motor milestones such as head control, sitting, rolling, crawling, ability to kick in supine position, standing and walking were noted.

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The FDA has also asked the sponsor to conduct analysis and evaluate the results. Out of 121 patients, around 82 were eligible. 40% of patients who took the drug were found to show improvement in motor milestones were none of the control patients showed improvement.

Additional clinical trials for patients who received the drug from 30 days to 15 years of age and from 8 days to 42 days at the first time of the dose. These studies lack control group, however it was able to support the clinical efficacy of the drug.

Spinal Muscular Atrophy

• It is a genetic disease, that makes it difficult for the patient to move around and do physical tasks
• It is one of the genetic diseases that affects the children under the age of 2
• Spinal Muscular Atrophy is caused by a defective gene called survival of motor neuron (SMN)
• Around 1 in 40 people carry the gene that causes Spinal Muscular Atrophy
• There is no cure for SMA, however treatment includes managing the symptoms and complications

Nusinersen Drug
Nusinersen is a survival motor neuron 2 (SMN2) directed oligonucleotide which is indicated for the treatment of Spinal Muscular Atrophy. It is injected intrathecally (spinal cord injection) and is used for the treatment of all types of spinal muscular atrophy.

Common Side Effects of Nusinersen

• Respiratory tract infections
• Constipation

Warnings and precautions for Nusinersen drug may also include low blood platelet count, toxicity to the kidneys and the nervous system.

References

1. Spinal Muscular Atrophy - (https://medlineplus.gov/spinalmuscularatrophy.html)
2. What is SMA? Stop SMA - (http://www.stopsma.org/what-is-sma)
3. FDA approves first drug for spinal muscular atrophy - (http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm534611.htm)

Source-Medindia