As part of the National Institute for Health and Care Excellence (NICE) highly specialised technology (HST) evaluation programme, Novartis submitted evidence to support the use of onasemnogene abeparvovec as a treatment option for patients with pre-symptomatic 5q spinal muscular atrophy (SMA) with a bi-allelic mutation in the survival of motor neuron (SMN) 1 gene and up to three copies of the SMN2 gene. Here, SMN2 is linked to proximal spinal muscular atrophy.