OBJECTIVES: The recent advent of disease-modifying treatments, including onasemnogene abeparvovec, has dramatically improved prognosis for patients with SMA. However, real-world data are lacking – particularly for patients >6 months of age. We sought to understand physicians’ assessments of improvement among patients with SMA treated with onasemnogene abeparvovec.

METHODS: We distributed an electronic survey via e-mail to providers in the United States who treated patients with SMA between 6-24 months of age and evaluated improvement (defined by gains in one or more of the following domains: motor functioning, mobility, bulbar function, pulmonary function) as assessed by respondents. All results were summarized descriptively.

RESULTS: Among the providers who responded to the survey, 13 of them cared for 30 pediatric patients with SMA within the age range (all with ≥2 copies of SMN2) over the past year who received onasemnogene abeparvovec monotherapy; improvement was reported among 83.3% of patients. Mean time (months, ±standard deviation) to achieving improvements was 1.8±1.1 for motor functioning, 2.6±2.3 for mobility, 2.4±2.0 for bulbar function, and 2.1±1.2 for pulmonary function.

CONCLUSIONS: This provider survey shows that a large proportion of patients with SMA between 6-24 months of age achieved rapid improvement after receiving onasemnogene abeparvovec. Given the inherent limitations of physician survey studies, additional research including patient-level data is needed to further assess outcomes in this population.