The efficacy and safety of nusinersen within the expanded access program in Russia

Introduction. Spinal muscular atrophy is a severe neuromuscular disease characterized by rapid progression of muscle weakness and early death. Pathogenetic therapy with nusinersen can significantly change the course of the disease and enable the patient to acquire new skills. The study of the efficacy and safety of nusinersen therapy in patients with type 1 spinal muscular atrophy should be continued. The aim of the study was to assess the safety and efficacy of nusinersen therapy in patients with type 1 spinal muscular atrophy for 6 months as part of an expanded access program at federal and regional healthcare facilities. Materials and methods. Patients with type 1 spinal muscular atrophy received nusinersen therapy under the expanded access program (NCT02865109). Patients were evaluated before starting treatment and 6 months after starting treatment. Overall motor development and motor function was assessed using the Hammersmith Infant Neurological Status Scale Part 2 and the Philadelphia Pediatric Hospital Neonatal Motor Scale. Results. 41 children aged 6 to 38 months received nusinersen therapy between July 2019 and March 2020. At the time of analysis, all patients were alive and continued treatment. The average improvement on the Hammersmith Hospital Neurological Status Scale was 3.7 points after 6 months of therapy compared to baseline (n = 39, p <0.001). The mean improvement on the Children’s Hospital of Philadelphia Scale for the Diagnosis of Motor Function in Newborns was 9.8 after 6 months of therapy from baseline (n = 30, p <0.001). Conclusion. The efficacy and safety of nusinersen have been demonstrated in real clinical practice in Russia in the treatment of early-onset spinal muscular atrophy.