As written in BioSpace, Genetech has recently presented new two-year data on their spinal muscular atrophy (SMA) treatment, evrysdi. The information was released at the 25th International Annual Congress of the World Muscle Society, which was held virtually due to COVID-19.
About Spinal Muscular Atrophy (SMA)
Spinal muscular atrophy (SMA) is rare genetic order that is characterized by muscle weakness and degeneration. It affects one in every 10,000 people but can vary in severity from person to person. A mutation in the SMN1 causes this condition, and it causes the loss of motor neurons in the spinal cord and brain stem. Due to this loss, muscles weaken and atrophy, specifically the muscles used for walking, breathing, swallowing, crawling, sitting up, and moving the head. The symptoms of this condition depend on the severity and type of SMA. Type I is the most severe, and is diagnosed after birth. The symptoms of this type include developmental delay, the inability to sit up or move the head, and trouble with breathing and swallowing. Type II is diagnosed in children between six and twelve months old, and they experience trouble with standing and walking. Those who have type III are diagnosed between early childhood and adolescence and cannot walk or climb stairs independently. Type IV occurs in adults over 30 and is the least severe type. People with this form of SMA usually have mild muscle weakness, problems with breathing, twitches, or tremors.
Once these symptoms are noticed, a diagnosis is confirmed through neurological examination and genetic testing. While there is no cure for SMA, there are treatments available. Physical therapy, braces, and surgery can all help to improve movement. Noninvasive respiratory support and tracheostomies can address issues with breathing while gastrostomy can help with eating. Spinraza is the first FDA approved treatment for SMA, and Zolgensma has also recently been approved.
Evrysdi is a survival of motor neuron 2 (SMN2) splicing modifier that specifically treats SMA caused by chromone 5q mutations. It can be administered orally or through a feeding tube, making it possible to be given at home daily.
It has already been approved in the US by the FDA for adults and children over the age of two, along with reaching approval in South Korea, Taiwan, Australia, India, and other countries. The EU, Canada, Switzerland, and China are also reviewing applications currently.
Four trials are evaluating evrysdi to help it reach approval in other countries and to learn more about the treatment. They are FIREFISH, SUNFISH, JEWELFISH, and RAINBOWFISH.
The Data Presented
Genetech presented data from the first part of the FIREFISH trial, which evaluated evrysdi in SMA patients age two to seven months. The results were positive:
- 88% of participants survived and did not require ventilation
- 59% were able to sit without support for five seconds
- 30% were able to stand
- 29% were able to turn themselves over
- 65% had upright head control
- 71% reached a CHOP-INTEND score of 40 points
- 100% increased their score over the course of the study
- 100% were able to swallow
- 93% could be fed orally
The safety profile was maintained, and the majority of adverse effects were mild. This data is very exciting, as it proves again that evrysdi is a viable treatment option for those with SMA.