2023 American Academy of Neurology Abstract Website

Objective:

We aim to understand the benefits between two therapies in adults and potential adverse events.

Background:

Spinal Muscular Atrophy is an autosomal recessive disorder causing progressive degeneration of anterior horn cell resulting in muscle weakness. This is due to mutation in SMN1 gene. SMA is phenotypically classified into 5 types based on age at onset of symptoms. Current approved therapies for adults include antisense oligonucleotide-Nusinersen and a small molecule mRNA splicing modifier-Risdiplam.

Design/Methods:

15 adult SMA patient who are on treatment with either Nusinersen or Risdiplam were reviewed and RULM score, treatment adverse effect data were collected.

Results:

We reviewed a total of 15 adult SMA patients. The mean age was 44.6 years (30-64) and 10 were female. 10 had 3 copies, 3 had 4 copies and 1 had 2 copies of SMN2 gene. 12 patients received Nusinersen out of which 7 switched to Risdiplam. The RULM scoring that was performed at each of their clinic visit were collected for pre and post treatment from 2018 to 2022. On Nusinersen 7/12 (58.3%, p-value 0.003) showed increase in their scores while 2/12 (16.6%) showed decrease and 3/12 (25%) showed no change. Most improvement was observed in fine motor category. On Risdiplam 1/7 (14.2%) showed increase and 4/7 (57.1%) showed decrease in scores and 2/7 (28.5%) were stable. There were no serious adverse events related to intrathecal administration of Nusinersen and were switched to Risdiplam due to patient preference or no improvement in scores. Only one patient discontinued Risdiplam due to significant GI side effects.

Conclusions:

In our single center experience Nusinersen was seen to have better functional outcome RULM scores in comparison to Risdiplam. This however is subject to limited number of patients on Risdiplam and phenotypic variability in patients. There were no serious adverse effects in either of the medications.