New Study Finds Evrysdi (Risdiplam) Triggers Cellular Changes Beyond Motor Neurons in Adults with SMA
A new peer-reviewed study of adults living with spinal muscular atrophy (SMA) has shed light on how Evrysdi (risdiplam) affects the body at a cellular level — including some differences you might not expect between SMA types 2 and 3.
Researchers at the University of Bari in Italy studied 16 adults with SMA types 2 and 3 (11 with type 2 and five with type 3), taking blood samples before treatment and again after 12 months on Evrysdi. Using a technique called RNA sequencing, they tracked which genes were switched on or off in blood cells over the course of treatment.
What did they find?
As expected, patients on Evrysdi showed increased levels of the healthy version of the SMN2 gene transcript — this is exactly how the drug is designed to work, helping the body produce more functional SMN protein.
But the study also picked up some effects that go beyond the drug's known target:
- Genes linked to mitochondria (the tiny structures inside cells that produce energy) were more active after treatment.
- Genes involved in autophagy — the process cells use to clear out damaged components — were less active.
- There were measurable molecular differences between people with type 2 and type 3 SMA, suggesting the two types may respond somewhat differently at a cellular level, even to the same treatment.
The researchers say these findings could be "of some relevance for future clinical and therapeutic strategies" — in other words, understanding these wider cellular effects might eventually help doctors fine-tune treatment or explain why people respond differently to the same medicine.
What this means for families
This is early-stage, exploratory research based on a small group of 16 adults, so it won't change how Evrysdi is prescribed today. Nusinersen, risdiplam and onasemnogene abeparvovec remain the three treatments routinely available on the NHS in England following NICE's approval earlier this year. But findings like these add to the wider scientific understanding of how SMA treatments work throughout the body, not just in motor neurons — something researchers hope could inform better monitoring and future combination therapies down the line.
TreatSMA will continue to follow research like this and keep you updated on anything that could affect how SMA is treated and monitored in the UK.