Onasemnogene abeparvovec is recommended as an option for treating presymptomatic 5q spinal muscular atrophy (SMA) with a biallelic mutation in the SMN1 gene and up to 3 copies of the SMN2 gene in babies aged 12 months and under. It is only recommended if the company provides it according to the commercial arrangement.
Why the committee made this recommendation
This guidance is a partial review of NICE's highly specialised technologies guidance on onasemnogene abeparvovec for treating SMA. It focuses on new clinical trial evidence for onasemnogene abeparvovec for presymptomatic SMA.
SMA is a rare genetic condition. A few children are diagnosed with SMA using genetic testing before symptoms appear if a sibling has been diagnosed with the condition. If untreated, presymptomatic SMA will develop into one of several types of SMA of varying severity and symptoms. There are no routinely commissioned treatments for presymptomatic SMA for use in the NHS. If presymptomatic SMA develops into type 1 SMA, onasemnogene abeparvovec is an available treatment option in certain situations.
Evidence from a clinical trial suggests that onasemnogene abeparvovec is effective for presymptomatic SMA in babies. But it is difficult to estimate how well onasemnogene abeparvovec works, primarily because the trial only included babies aged 6 weeks and under, and treatment before this time point is not always possible in NHS clinical practice. Also, there is a lack of long-term evidence for onasemnogene abeparvovec in presymptomatic SMA.
Despite the high levels of uncertainty, there is evidence that onasemnogene abeparvovec provides substantial health benefits, such as reaching important motor milestones, for babies with presymptomatic SMA. The cost-effectiveness results show a lower overall cost compared with onasemnogene abeparvovec for type 1 SMA and best supportive care for types 2 and 3 SMA for babies aged 6 weeks and under. For babies with presymptomatic SMA aged over 6 weeks to 12 months and under, the cost-effectiveness estimates are still likely to be within the range that NICE considers an effective use of NHS resources for highly specialised technologies. So, onasemnogene abeparvovec is recommended for use in the NHS for presymptomatic SMA in babies aged 12 months and under, that is, in line with the population in the managed access agreement in NICE's highly specialised technologies guidance on onasemnogene abeparvovec for treating SMA.