In 2016, Spinraza® became the by the first FDA-approved treatment for spinal muscular atrophy (SMA). This neurodegenerative disease is the leading genetic cause of infant death. The drug was conceived and developed by Cold Spring Harbor Laboratory (CSHL) Professor Adrian Krainer and collaborators. But Prof Krainer’s lab continued to try and improve Spinraza® could be improved, in collaboration with Alberto Kornblihtt at Universidad de Buenos Aires. They discovered pairing Spinraza® with a second FDA-approved drug called valproic acid (VPA) could be a new way to boost its therapeutic effects, without increasing toxic side effects.
Prof Krainer explained: “Sometimes you don’t want to use a ton of a drug. If you have a condition that allows you to use less drug, then you may have fewer toxicities. So the idea is to combine these two drugs to get maximal effects.”
In SMA, the body produces insufficient amounts of a protein called SMN. Spinraza® is a type of molecule called an antisense oligonucleotide (ASO) that helps cells make more SMN protein from a gene called SMN2. Roadblocks were discovered on the SMN2 gene when using Spinraza®, slowing down the cellular machine producing SMN protein. The drug VPA helps remove these roadblocks, allowing Spinraza® to further increase the SMN protein output. When mice with SMA were treated with both VPA and a Spinraza®-like ASO used for research, the mice survived longer, with improved muscle function.
To date, more than 11 000 SMA patients have been treated with Spinraza® in more than 50 countries. Prof Krainer’s latest research shows that there’s always room for improvement. He hopes the team’s findings will help optimize the efficacy of Spinraza® treatments, and hopes their work will help the development of treatments for other neurodegenerative diseases.
Source: Cold Spring Harbor Laboratory
