Children with SMA type 1 still see benefits after 4 years on Evrysdi
All treated children alive at the time of the last analysis were still alive after four years
A growing number of young children with spinal muscular atrophy (SMA) type 1 who started taking Evrysdi (risdiplam) as babies are gaining the ability to sit, stand, and walk, according to four-year data from the FIREFISH clinical trial.
No new deaths have been reported since the study’s primary analysis, with 91% of FIREFISH enrollees still alive after four years and 95% maintaining the ability to swallow.
The findings were presented at the CURE SMA Research & Clinical Care Meeting in Orlando, Florida.
“The independence that comes with sitting, standing and walking is transformational for children with SMA, and their families, and we are very encouraged by how these skills increased over four years of Evrysdi treatment for many children in this study,” Levi Garraway, MD, PhD, Genentech’s chief medical officer and head of global product development, said in a company press release.
Babies with SMA type 1 fail to acquire motor milestones in the disease’s natural course and never achieve the ability to sit up independently and require breathing and feeding support. Left untreated, they aren’t expected to live past age 2.
Evrysdi is an oral medication that increases levels of the SMN protein that’s lacking in SMA patients. Developed by Genentech in collaboration with PTC Therapeutics and the SMA Foundation, it’s approved in the U.S. to treat any age.
“Evrysdi’s oral route of administration allows the medicine to be distributed throughout the body, systemically increasing SMN protein production, the lack of which is the underlying cause of SMA,” said Giovanni Baranello, MD, PhD, of the Carlo Besta Neurological Research Institute Foundation. “This has shown to help in delivering a meaningful impact on important functions of daily living.”
After 4 years of Evrysdi
The Phase 2/3 FIREFISH trial (NCT02913482) enrolled 62 patients with SMA type 1, ages 1-7 months. That included 21 patients treated in the study’s initial, dose-finding part, and 41 treated with Evrysdi at its approved dose in the second part.
Data after a year of treatment in both parts of the trial indicated Evrysdi defied the disease’s natural history, with most babies surviving up to a year without needing permanent ventilation and many achieving and maintaining motor milestones they weren’t expected to meet.
Four-year data now indicate continued gains for the participants, who are now young children. All Evrysdi-treated children who were alive at the time of the last analysis (91%) were still alive after four years, and most (95%) maintained the ability to swallow. Many continued to improve the ability to sit, stand, and walk without support after four years, according to Genentech.
Specifically, 37 of 58 children across both trial parts were able to sit without support for at least five seconds and 36 could do so for at least 30 seconds, compared with 35 and 23 children who met these milestones, respectively, after two years.
Also, three more infants gained the ability to stand alone and one child gained the ability to walk alone since the two-year analysis.
The rate of side effects fell by 71% in the fourth year of treatment compared with the first year. The most common side effects were fever, upper respiratory tract infection, and pneumonia. Hospitalization rates decreased during the study.
“Nine out of 10 patients in our studies remain on Evrysdi long-term and these data underscore its importance as an option for people with SMA across a broad range of age and disease types,” Garraway said.