A Study Evaluating the Effectiveness and Safety of Risdiplam Administered as an Early Intervention in Pediatric Participants With Spinal Muscular Atrophy After Gene Therapy

Eligibility Criteria

• * \<2 years of age at the time of informed consent
• * Confirmed diagnosis of 5q-autosomal recessive SMA
• * Confirmed presence of two SMN2 gene copies
• * Administration of onasemnogene abeparvovec pre-symptomatically or post-symptomatically
• * Has received onasemnogene abeparvovec for SMA no less than 3 months, but not more than 7 months, prior to enrollment
• * Has, in the opinion of the investigator, not experienced clinically significant decline in function from the time of onasemnogene abeparvovec administration
• * Treatment with investigational therapy prior to initiation of study treatment
• * Any unresolved standard-of-care laboratory abnormalities per the onasemnogene abeparvovec prescribing information
• * Concomitant or previous administration of a SMN2-targeting antisense oligonucleotide or SMN2 splicing modifier either in a clinical study or as part of medical care
• * Requiring invasive ventilation or tracheostomy
• * Requiring awake non-invasive ventilation or with awake hypoxemia (SaO2 \<95%) with or without ventilator support
• * Presence of feeding tube and an OrSAT score of 0
• * Hospitalization for pulmonary event within the last 2 months, or any planned hospitalization at the time of screening
• * Any major illness requiring hospitalization within 1 month before the screening examination or any febrile illness within 1 week prior to screening and up to first dose administration.