The U.S. Food and Drug Administration announced Dec. 23 that it has approved Spinraza (nusinersen), making the Biogen drug the first available for treating spinal muscular atrophy in adults and children.

SMA is characterized by a motor neuron loss, leading to severe and progressive weakness and atrophy in the muscles. Those with the most severe type of the disease can eventually become paralyzed and have trouble performing basic life functions like swallowing and breathing.

"There has been a long-standing need for a treatment for spinal muscular atrophy ... We could not be more pleased to have the first approved treatment for this debilitating disease," said Dr. Billy Dunn, Division of Neurology Products director at the FDA's Center for Drug Evaluation and Research.

Nusinersen Clinical Trials

The approval was granted after desired results were met in ENDEAR, a clinical trial involving 121 patients diagnosed with infantile-onset SMA before they were 6 months of age and who were less than 7 months old during the time their first dose was administered.

Additionally, open-label uncontrolled clinical studies were carried out on symptomatic patients between the ages of 30 days and 15 years at the time of first dose, and presymptomatic patients between the ages of 8 and 42 days at the time of first dose. Without control groups, these studies made it more difficult for researchers to interpret them but their results nonetheless supported what ENDEAR yielded.

"Spinraza offers new hope for the SMA community and exemplifies our mission of applying cutting-edge science to make a meaningful difference in the lives of patients with devastating, life-altering diseases," said George A. Scangos, Biogen CEO.

He also said Biogen is grateful to patients and their families for participating in ENDEAR and acknowledged the efforts of the clinical trial's researchers, as well as the contributions of Ionis Pharmaceuticals, which initiated the program.

FDA Spinraza Approval

Alongside approval as a treatment drug for SMA, Spinraza was also granted by the FDA orphan drug designation, which gives incentives to encourage and assist pharmaceutical companies to develop medications for rare diseases.

It also received priority review status and a fast track designation, as well as a rare pediatric disease priority review voucher for Biogen that the company can redeem at a later date for a subsequent application for a different product. Since the rare pediatric disease priority review program was created to spur the development of treatments for rare pediatric diseases, this is the eighth voucher to be given out by the FDA.

Spinraza is scheduled to be made available to healthcare providers in the United States in about one week. According to Biogen, they are anticipating that there will be variations in how soon SMA patients can receive the treatment as institutions and treatment centers learn more about the drug.

Designed to be given via intrathecal injection, Spinraza is directly delivered to cerebrospinal spinal fluid around the spinal cord. It's in this area where SMA patients experience motor neuron degeneration because of low levels of the survival motor neuron protein.

Photo: Del Mich | Flickr