Hand strength improves for adults with SMA types 2, 3 taking Evrysdi
Evrysdi (risdiplam) effectively improved motor function in adults with spinal muscular atrophy (SMA) type 2 or type 3, particularly skills like hand strength and function, a small study in France shows.
Most patients also reported gains in bulbar functions, that is, speaking, chewing, and swallowing, and eased breath fatigue.
Evrysdi “is a well-tolerated treatment in our cohort of adult type 2 and type 3 SMA patients and resulted in improvement or stabilization in motor functions,” wrote the researchers, who noted the “meaningful improvements” were sustained throughout two years of therapy.
The study, “Risdiplam: therapeutic effects and tolerability in a small cohort of 6 adult type 2 and type 3 SMA patients,” was published in the Orphanet Journal of Rare Diseases.
SMA is a neuromuscular disease mostly caused by mutations in the SMN1 gene, which result in low or no production of the SMN protein, the loss of which particularly affects nerve cells that control voluntary movements, called motor neurons, leading to symptoms like muscle weakness and wasting.
Evrysdi is a disease-modifying treatment marketed by Roche and Genentech that increases levels of functional SMN protein by binding to and modulating the activity of the SMN2 gene, which normally produces 10% to 15% of the SMN protein produced by SMN1. The treatment is approved in the U.S. and in Europe. In the U.S., it’s approved for all types of SMA in children and adults of all ages. But “few data of adult patients treated by [Evrysdi] are published,” the researchers wrote.
Gains in motor function, strength
Researchers in France led a study that described the use of Evrysdi in six adults with either SMA type 2 (4) or type 3 (2) who couldn’t walk. In SMA type 2, symptoms appear between 6-18 months of age, while in the milder SMA type 3, symptoms start between 18 months and the end of adolescence.
The patients had a mean age of 40.5 (range, 21-65) and four were women. The two SMA type 3 patients had been treated with Spinraza (nusinersen), but it was suspended due to side effects. All the patients in this study were treated with Evrysdi at a daily dose of 5 mg.
After a mean period of 16 months of treatment, all the SMA type 2 patients saw gains in motor function, as assessed by the 32-item Motor Function Measure (MFM32). The SMA type 3 patients had a nonsignificant worsening of motor function, with no changes in clinical status.
The improvement in three SMA type 2 patients was observed in the MFM32 score’s D2 domain, which assesses axial muscles (trunk and head) and proximal limbs (upper arms and upper legs). It remained stable in an SMA type 3 patient and decreased in the two others.
Regarding motor function in the distal limbs (lower arms and legs, hands, and feet), four patients showed clinically significant benefits, whereas one worsened. No differences were seen in the ability to stand or transfer between positions, nor in the Hammersmith Functional Motor Scale-Expanded of motor function.
“MFM32, showing sustained amelioration over time in the majority of patients, is confirmed to be a useful tool able to detect minimal changes in motor function induced by the therapy,” the researchers wrote.
Five patients reported improvements in breath fatigue, voice, and hand strength and dexterity, that is, the ability to make coordinated finger movements to grasp and manipulate objects. Four patients reported greater cough strength, less fatigue, and better quality of life. Three reported improved arm mobility. Two patients described better chewing, swallowing, bowel function, and cognition.
The treatment was well tolerated and most adverse events — sensitivity to light (67%), diarrhea (67%), transient elevation of liver enzymes (50%), and kidney stones (33%) — were mild and decreased over time.
Evrysdi was effective overall and safe in adults with SMA, said the researchers, who wrote “future efforts to conduct clinical studies in larger cohorts are highly desirable in order to better characterize and quantify the effects of [Evrysdi] on adult patients, and to establish effective outcome measures.” Limitations to the study included its small size and there being no placebo or control group.
The post Hand strength improves for adults with SMA types 2, 3 taking Evrysdi appeared first on SMA News Today.
