Search

Spinal muscular atrophy (SMA) is a motor neuron disease associated with progressive muscle weakness, ventilatory failure, and reduced survival. Onasemnogene abeparvovec is the first gene replacement therapy (GT) approved to treat this condition. An observational retrospective study was conducted to assess adverse events and efficacy of GT in SMA patients. Forty-one patients with SMA (58.5% females and 80.1% SMA type 1) were included. The mean age at GT dosing was 18 (±6.4) months. Thirty-six patients (87.8%) were under previous treatment with nusinersen, and 10 (24.4%) continued nusinersen after GT. Mean CHOP-INTEND increased 13 points after 6 months and this finding did not differ between groups according to nusinersen maintenance after GT (p = 0.949). Among SMA type 1 patients, 14 (46.6%) reached the ability to sit alone. Liver transaminases elevation at least two times higher than the upper limit of normal value occurred in 29 (70.7%) patients. Thrombocytopenia occurred in 13 (31.7%) patients, and one presented thrombotic microangiopathy. Older age (>2 years) was associated with more prolonged use of corticosteroids (p = 0.021). GT is effective in SMA patients, combined nusinersen after GT did not appear to add gain in motor function and older age is associated with prolonged corticosteroid use., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

BackgroundSpinal muscular atrophy (SMA) is a motor neuron disease associated with progressive muscle weakness and motor disability.ObjectiveThis study aims to report the evaluation of nusinersen, an antisense oligonucleotide, on motor function in patients with SMA types 2 and 3.MethodsThis single-center retrospective observational study assessed nusinersen therapy outcomes, measured by HSMFSE or CHOP-INTEND scales, in patients with SMA types 2 and 3, compared to untreated patients, for at least 24 months.ResultsA total of 41 patients with SMA types 2 and 3 under nusinersen treatment were included. In 30 treated patients (mean age: 10.6 years; 14 with SMA type 2), the mean change in HFMSE scores was +1.47 points (SD = 0.4) and +1.60 points (SD = 0.6) after 12 and 24 months of treatment, respectively. In contrast, the control group (N = 37) (mean age: 10.2 years; 20 with SMA type 2) presented a mean change of -1.71 points (SD = 0.02) and -3.93 points (SD = 0.55) after 12 and 24 months of follow-up, respectively. The most severe patients under nusinersen treatment (N = 11) showed a change of +2.37 (SD = 1.13) on the CHOP-INTEND scale after 12 months of follow-up. Disease duration at the beginning of treatment was the main predictor of functional improvement. Despite functional gain and motor stabilization, treatment with nusinersen did not prevent the progression of scoliosis.ConclusionsOur data provide evidence for the long-term safety and efficacy of nusinersen use in the treatment of later-onset SMA, and patients with shorter disease duration showed better response to treatment.