Spinraza, marketed by Biogen, was the first approved treatment for SMA in Europe.
Spinraza™ is an antisense oligonucleotide designed to modify the product of the SMN2 “backup” gene to produce more functional SMN protein. This protein is essential for motor neurons to function and remain healthy.
Antisense oligonucleotide drugs (ASOs) are small snippets of synthetic genetic material that bind to ribonucleic acid (RNA). They are often described as molecular patches because they can be specifically designed to target and affect how a particular gene is read. ASOs have great potential for SMA, because they can accurately target the SMN2 gene to essentially convert it into the SMN1 gene, i.e. they are small molecules “patching-up” SMN2 to act more like SMN1. So they can be used to fix splicing errors in genes such as SMN2. They do this by binding to the RNA template made by SMN2 and enhancing the inclusion of exon 7 into the SMN protein.