This is the first therapy approved by Health Canada for the treatment of SMA. The drug is specifically indicated to treat 5q SMA, which represents about 95 percent of all SMA cases, making it the most common type of SMA.
Spinraza is an antisense oligonucleotide (ASO) designed to treat SMA caused by mutations or deletions in the SMN1 gene located in chromosome 5q, which leads to SMN protein deficiency. Spinraza targets the SMN2 gene in order to increase production of SMN protein. This way, Spinraza has the potential to increase the amount of fully-working SMN protein in SMA patients.
“Today, Biogen is very proud to share the news that Health Canada has approved SPINRAZA for the treatment of 5q SMA. Based on the robust efficacy and safety profile demonstrated in the clinical trials, we believe SPINRAZA will have a meaningful impact on individuals living with this devastating disease,” Wildon Farwell, Biogen Canada’s senior director of clinical development, said in a press release. “Biogen is committed and willing to continue to work with healthcare professionals, advocacy groups and government agencies to ensure people who could benefit from SPINRAZA receive access to this important treatment as quickly as possible.”
Health Canada’s decision to approve Spinraza was based on positive results from a series of clinical trials including more than 170 participants. The data package backing the regulatory decision included results from the Phase 3 ENDEAR study (NCT02193074), which evaluated Spinraza in infantile-onset SMA.
Results from ENDEAR showed that patients who received Spinraza achieved and sustained clinically meaningful improvements in motor function when compared to subjects who did not receive treatment with Spinraza.
Additional open-label studies showed that certain patients were able to achieve milestones such as the ability to sit without requiring assistance, stand up or walk when they would otherwise not be able to do so, and maintain these achievements at ages when they would not be expected to do so.
Most common side effects reported included upper respiratory/lower respiratory infection and constipation.
These findings were considered sufficient to support the decision to approve Spinraza in the treatment of 5q SMA, as well as to support the early initiation of treatment.
Spinraza became the first treatment approved by the U.S. Food and Drug Administration (FDA) to treat SMA in both children and adults on Dec. 23, 2016, under a priority review program for rare diseases.
On June 21, 2017, Spinraza also was granted a marketing authorization by the European Medicines Agency (EMA) for the treatment of 5q SMA.
Regulatory filings in Australia, Brazil, Japan and Switzerland are underway.