SMN2 and spinal muscular atrophy, type 1: ,19,20 Subsequent phase 3 trials have further confirmed the efficacy of onasemnogene abeparvovec in patients with SMA type 1 (STR1VE [ClinicalTrials.gov: NCT03306277] and STR1VE-EU [ClinicalTrials.gov: NCT03461289]) and in presymptomatic patients with two or three SMN2 gene copies at risk for developing SMA (SPR1NT; ClinicalTrials.gov: NCT03505099).14