FDA and EMA Accepts Applications for New Nusinersen Regimen

woman with SMA © Framestock - stock.adobe.com

The FDA has accepted Biogen’s supplemental New Drug Application (sNDA) for a higher dose regimen of nusinersen to advance the treatment of spinal muscular atrophy (SMA), according to today’s news release. The European Medicines Agency (EMA) has also accepted this new regimen, which consists of two 50 mg doses 14 days apart and a maintenance dose of 28 mg, every four months. Nusinersen is currently marketed as Spinraza worldwide.

The current approved regimen is four 12 mg doses administered over 60 days, followed by maintenance dosing every four months. Both therapies are injected directly into the lumbar spine.

These approvals were based on the results of the DEVOTE phase 2/3 study, in which safety and efficacy was studied in 145 SMA patients at 42 sites around the world. In the Part B cohort, researchers reported a clinically meaningful reduction in symptoms at six months among treatment-naïve children with infantile-onset SMA on the higher dose when compared to patients on the already approved lower dose.

The safety and efficacy of the higher dose regimen were generally consistent with the lower dose regimen. The most common adverse events were lower respiratory infection and constipation. However, serious adverse events were less frequent in the higher dose group, affecting 60% vs. 72%, of patients, respectively.

SMA is a hereditary disease caused by low levels of the survival motor neuron (SMN) protein, which is essential for controlling muscle movement. As a result, neurons disintegrate, resulting in progressive muscle weakness, especially in the trunk. It can be diagnosed at any age and symptoms are progressive. There is currently no cure for SMA.

Nusinersen is an antisense oligonucleotide, which increases the amount of SMN protein in the body.It is currently sold in over 71 countries and is approved to treat infants, children and adults with SMA. More than 14,000 patients have been treated with nusinersen worldwide.

“Continued progress to improve upon the remarkable initial successes in SMA necessitates an innovative approach,” Thomas Crawford, M.D., co-director of the Muscular Dystrophy Association Clinic at Johns Hopkins Medicine said in the release. “Today’s announcement is a significant step forward for the community. Results from the DEVOTE study have shown us that the higher dose regimen of nusinersen can enable meaningful clinical benefits while maintaining a safety profile broadly consistent with the approved 12 mg regimen.”

Biogen is unable to comment on the pricing of investigational treatments, according to a media representative from their company.