Children with Spinal Muscle Atrophy Treated Presymptomatically With Nusinersen Are Sitting Independently and Walking
Infants with spinal muscle atrophy (SMA), who were diagnosed through genetic testing and treated with nusinersen (Spinraza; Biogen, Cambridge, MA) prior to the onset of symptoms survived without tracheostomy or permanent ventilation and also achieved major motor milestones.
At age 14 months or more, all 25 infants treated are able to sit independently and 22 (88%) of the children treated are walking with assistance or independently. The children’s motor skills were assessed with World Health Organization (WHO) and Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) tests. The CHOP INTEND test assesses and scores 16 types of movement to create an overall score between 0 and 64. Children with SMA Type 1 and Type 2/3 had mean CHOP INTEND scores of 61 and 62.6 respectively.
These data are from interim analysis of the the NURTURE study (NCT02386553), in which 15 infants with the SMA Type 1 genotype and 10 infants with SMA Type 2/3 genotypes were treated on an open-label extension basis.
“The NURTURE study results demonstrate that early diagnosis and treatment with Spinraza has the potential to dramatically change the course of SMA,” said Wildon Farwell, M.D., senior medical director, clinical development at Biogen. “This is the longest available span of data on infants with SMA who began treatment in a presymptomatic period and indicates that children treated early with Spinraza can achieve motor milestones they would likely not attain without treatment.”
Additional research presented at the World Muscle Society meeting in Mendoza, Argentina showed that patients treated with nusinersen experienced rapid lowering of phosphorylated neurofilament heavy chain (pNF-H) blood levels that approached blood levels of pNF-H seen in healthy subjects. These results are a part of efforts to identify and validate biomarkers for understanding the disease progression of SMA.
Nusinersen is an antisense oligonucleotide (ASO) treatment delivered via an intrathecal injection that upregulates the production of survival of motor neuron (SMN) protein by binding to and altering splicing of RNA.