Onasemnogene Abeparvovec as New Gene Therapy in Patients with Spinal Muscular Atrophy – a Review of the Literature

Abstract Introduction Spinal muscular atrophy is an autosomal recessive neurodegenerative disease that mainly affects children. It is caused by mutation in the SMN1 gene, which results in degeneration and loss of alpha motor neurons innervating skeletal muscles. Without any intervention, spinal muscular atrophy progresses and leads to disability or even early death. Material and methods The latest available literature accessible on the Pub-Med database was reviewed. Thirty papers, which were published in English, available as full-text publications, and published since 2015, were selected for analysis. Results Depending on the level of motor development and the age of onset, spinal muscular atrophy is divided into 4 or 5 subtypes. Onasemnogene abeparvovec is a gene replacement therapy and consists of a vector of the serotype 9 adeno-associated virus, which delivers a functional copy of the SMN1 gene to the cells of the motor neuron. Important advantage of the drug is single administration via an intravenous route. The limitation is the high price and the lack of studies in older children. Several studies confirmed the efficacy and safety of using onesamnogene abeparvovec in children who afterward made progress in respiratory functions, swallowing, and motor milestones, like head control and sitting independently. Conclusions Onasemnogene abeparvovec is an innovative and effective drug with great potential for present and future use. Therapy in spinal muscular atrophy should be implemented as early as possible to avoid muscle cell loss. It is important to conduct universal screening tests of newborns to detect the disease before the first symptoms appear.