Two studies presented at the AAN Annual Meeting 2017 in Boston (MA, USA) have demonstrated positive results for nusinersen (Spinraza® Biogen (MA, USA) in the treatment of spinal muscular atrophy (SMA).
Nusinersen is an antisense oligonucleotide designed to treat SMA caused by mutations or deletions in the SMN1 gene located in chromosome 5q, which lead to SMN protein deficiency. Through alteration of SMN2 pre-mRNA, nusinersen acts to increase production of SMN full-length protein.
In the Phase III CHERISH study, 126 children who had experienced SMA symptom onset aged 6 months or older were randomized to nusinersen treatment or placebo control. In end of study analyses presented at the meeting, those assigned to the nusinersen treatment group demonstrated statistically significant and clinically meaningful improvements in motor function compared with controls.
The nusinersen safety profile was also found to be favourable in this study, with treatment-emergent, severe and serious adverse events all reported less frequently in children assigned to treatment.
“In CHERISH, most children with later-onset SMA treated with Spinraza saw improvements in motor function and stabilization or slowing of disease progression,” explained Nemours Children’s Hospital (FL, USA) Chief of Neurology Richard Finkel.
“As a physician who has spent 37 years treating children with SMA, it’s incredibly encouraging to see some patients on Spinraza achieve milestones such as crawling and standing with assistance within the clinical trial. These kinds of clinically meaningful improvement are unprecedented and give hope to individuals with SMA and their families.”
Also presented at the meeting were new interim data from the Phase II NURTURE study, investigating nusinersen treatment of infants under 6 weeks old who have genetic SMA diagnoses but are presymptomatic at treatment initiation. At the time of reporting, 20 infants have been enrolled, most of whom have achieved motor and growth milestones comparable with normal development. Three infants have reported adverse events possibly related to treatment but none have discontinued or withdrawn.
“The results from NURTURE are significant , as they continue to demonstrate the importance of beginning Spinraza treatment as soon as possible after an SMA diagnosis and the major impact that early treatment may have across a broad range of SMA populations,” summarized Biogen executive Vice President and chief medical officer Alfred Sandrock.