New Results from Biogen’s NURTURE Study of Pre-Symptomatic Infants with SMA

09 October 2018

NURTURE is a study investigating the effect of Nusinersen on infants with SMA before the onset of symptoms (including muscle weakness). The central problem in infants with SMA is that they lack the ability to make sufficient ‘survival of the motor neuron’ (SMN) protein, due to a lack of a functioning SMN1 gene. There is a second gene (SMN2) that can make this protein, however it doesn’t make enough. Sometimes there are more copies of the SMN2 gene and this is associated with milder symptoms and a later onset (see this page).

Infants were selected to receive treatment in the NURTURE trial if they had no clinical signs of SMA and 2-3 copies of the SMN2 gene. Infants with 2-3 copies of the SMN2 gene would be expected to have SMA Type 1 (never manages to sit unsupported), Type 2 (achieves sitting but never manages to walk unsupported) or Type 3a (the infant manages to walk but has onset of symptoms before the age of 3 years). The intention of the study is to show that earlier treatment can delay the onset of symptoms in infants with SMA.   

Biogen reported that all the participants were now 14 months or older and alive, with none requiring permanent ventilation. The majority of participants (22 out of 25 = 88%) were able to walk either with assistance or independently; all of the participants were able to sit without support.

The study also revealed results of the physiotherapist assessment which looks at function of muscles (CHOP INTEND) which is scored out of 64. Participants with three copies of the SMN2 gene (expected to be ‘less severe’) scored 62.6 on average, those with 2 copies of the SMN2 gene (expected to be the most severe SMA Type 1), scored only slightly lower at 61.