Objective: We aimed to describe real-world outcomes in patients with spinal muscular atrophy (SMA) aged ?6 months at the time of onasemnogene abeparvovec (OA) infusion.
Background: Interventional trials of OA demonstrated safety and efficacy in patients <6 months of age.
Methods: We evaluated patients aged ?6 months receiving OA (regardless of treatment with other disease-modifying treatments) in RESTORE (a comprehensive, prospective, multicenter, multinational, observational registry of patients with SMA).
Results: As of May 23, 2021, RESTORE included 117 patients with SMA aged ?6 months at OA infusion (51 [43.6%] were ?6–<12 months; 57 [48.7%] were ?12–<24 months; and 9 [7.7%] were ?24 months). The majority of patients (n=73/117; 62.4%) had two copies of the SMN2 gene. Thirty-eight (32.5%) participants received OA monotherapy; 26 (22.2%) were administered OA that was preceded and followed by nusinersen and/or risdiplam; and 53 (45.3%) switched from nusinersen to OA. Of 81 patients with information available, 41 (50.6%) weighed ?8.5 kg at OA infusion. At that time, the majority of patients (n=76/114; 66.7%) were diagnosed with SMA type 1 and 7/114 (6.1%) were presymptomatic. Of 28 patients with ?2 evaluable CHOP INTEND assessments, 25 (89.3%) increased or maintained score, and 18 (64.3%) achieved ?4-point increases (11 patients aged ?6–<12 months; 7 patients aged ?12–<24 months). Adverse event (AE) data were reported for 116 patients; 71 (61.2%) reported at least one treatment-emergent AE and 33 (28.4%) reported at least one serious AE (20 [17.2%] related to OA treatment).
Conclusions: Patients with SMA aged ?6 months at OA infusion benefited from treatment as measured by CHOP INTEND scores. The safety profile of OA in patients aged ?6 months at infusion is consistent with the overall AE profile for OA, with no apparent pattern of AE incidence or severity according to age at infusion.