Longitudinal assessment of respiratory status utilising the amended Great Ormond Street Respiratory Score in treated spinal muscular atrophy type 1 children

Spinal muscular atrophy type 1 phenotypes have changed since the introduction of disease modifying therapies. The Great Ormond Respiratory Score has been used to assess respiratory function in children with spinal muscular atrophy. This paper presents an updated version of the score and aims to describe preliminary data reviewing the two-year changes of respiratory status in a cohort of spinal muscular atrophy type 1 patients treated with monotherapy or sequential disease modifying treatments. Patients were assessed using the amended Great Ormond Respiratory score at baseline, 6 months, 12 months and 24 months. 59 patients were reviewed. In total, 32 first initiated nusinersen therapy, 16 first initiated onasemnogene abeparvovec and 11 first initiated risdiplam therapy. There was a significant difference in baseline Great Ormond Respiratory Score between the nusinersen group and the onasemnogene abeparvovec group (p = 0.002). Risdiplam data is limited and is identified as preliminary. The data identifies treatment prior to 6 weeks of age stabilise at a lower score, with this being impacted by age of treatment. Those treated after one year show worse scores but stabilise. Despite the switching between disease modifying treatments, the Great Ormond Respiratory Score is a useful and easy-to-use clinical outcome measure which can demonstrate change in respiratory status over longitudinal review.