Spinraza aids motor function for SMA children at center in China
None of the 52 patients in study showed typical loss of motor milestones
Treatment with Spinraza (nusinersen) led to improvements in motor function for nearly all children with spinal muscular atrophy (SMA) who received the therapy at a center in China, and among children who didn’t experience improvements, motor function was generally stable with Spinraza.
The findings were detailed in a paper, “Effects of nusinersen on motor function in children with spinal muscular atrophy: a retrospective study,” published in Frontiers in Neurology.
“Our study demonstrated the therapeutic effect of [Spinraza] on motor function in children with SMA types 1, 2, and 3,” the researchers wrote. “Despite a wide age range, varying functional capacity at treatment initiation and different comorbidities, in the majority of children their disease progression was stabilized and they benefited from [Spinraza] treatment.”
Spinraza was 1st SMA treatment to receive widespread approvals
Spinraza was the first treatment for SMA to receive widespread approvals. It’s given by injection into the spinal canal every few months, and it works to boost levels of the SMN protein whose defect causes the disease. Spinraza is sold by Biogen, which was not involved in the present study.
A team of scientists in China reviewed data from 52 SMA patients who were treated with Spinraza at their center from November 2020 to September 2023. Most of the patients had SMA type 2 (76.9%). There were also some with type 1 (9.6%) or type 3 (13.5%) disease. The median age when they started treatment was just shy of 4 years.
Patients’ motor function was assessed with a battery of measures including the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) and the Hammersmith Functional Motor Scale Expanded (HFMSE) — both of which are assessments of overall motor function — as well as the Revised Upper Limb Module (RULM), which specifically assesses function in the arms and hands.
Results showed most patients experienced improvements in these scores in the months after starting on Spinraza. The researchers noted the number of patients showing improved motor function tended to increase with longer time on treatment.
Improvement in motor function scores considered clinically significant
After just over a year on Spinraza, among patients with available data, average CHOP-INTEND scores improved by 4.6 points and HFMSE scores improved by 4.7 points, and RULM scores improved by an average of 2.7. For all three assessments, the average improvement was higher than the minimum that’s considered clinically significant, indicating an improvement in motor function that would be noticeable for patients in their day-to-day lives.
Further analyses indicated that improvements in motor function were generally less dramatic for patients who were older and/or had been living with SMA symptoms for longer when they started on Spinraza. This was expected as Spinraza can slow or stop the progression of SMA, but it generally can’t repair damage that’s already accrued.
Still, the researchers highlighted that none of the patients lost motor milestones (being able to sit, stand, etc.) that they had previously achieved, which is a marked contrast to the typical progression of untreated SMA, where motor function deteriorates over time.
“Taken together, our data suggested that SMA children showed an overall improvement in motor function after [Spinraza] treatment,” the scientists concluded.
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