Onasemnogene Abeparvovec (OA) is a highly effective treatment for spinal muscular atrophy (SMA), resulting in significant motor function improvements, a recently published study in BMC Neurology revealed.
The study also highlighted the importance of closely monitoring patients with SMA type 1 for respiratory and nutritional needs and the development of scoliosis, even in the short term after receiving OA treatment.
Read more about SMA therapies
The case series study collected data from patients with SMA with OA obtained from the Swiss Registry for Neuromuscular Disorders. The study used prospective observational methods and only included patients who met specific eligibility criteria, including those with biallelic SMN1 gene mutations, a maximum of three SMN2 gene copies, and those under 2 years of age with normal baseline blood values.
The study analyzed bulbar, motor, and respiratory function development, safety data, like liver function, platelet count, and cardiotoxicity, and the appearance of scoliosis.
Overall, 9 individuals were treated with OA and followed for 383 days. Of them, 6 were SMA type 1 (2 with nusinersen pretreatment), 1 was SMA type 2, and 2 were presymptomatic individuals. Study results indicated that in individuals with SMA type 1, the CHOP Intend score increased by 28.1 from a mean score of 20.5 at the baseline. At the end of the follow-up, it was found that 50% of patients with SMA type 1 required nutritional support, 17% required night-time ventilation, and 67% developed scoliosis.
“Our case series study demonstrates that OA is an effective disease-modifying treatment for SMA, a result that also was shown in clinical trials and other real-world studies,” the authors highlighted. SMN2 gene splice site modifier treatment has been shown to prolong survival, achieve motor milestones in patient with SMA type 1, and preserve motor functions in later-onset SMA types 2 and 3.
Onasemnogene Abeparvovec, an alternative treatment approach for SMA, was developed alongside SMN2 gene splice site modifier therapies. It delivers the human SMN1 gene through a single intravenous dose of an adeno-associated viral vector (AAV9). Gene addition therapy has been shown to improve survival rates and help patients with SMA type 1 achieve important motor milestones, even in presymptomatic individuals.
Stettner GM, Hasselmann O, Tscherter A, et al. Treatment of spinal muscular atrophy with Onasemnogene Abeparvovec in Switzerland: a prospective observational case series study. BMC Neurol. Published online February 28, 2023. doi: 10.1186/s12883-023-03133-6