New Drug for Spinal Muscular Atrophy Shows Promise
Despite the benefits observed, the improvements still do not represent normal muscle function.
HealthDay News -- An experimental drug for infants with spinal muscular atrophy type 1 appears to be effective, according to research published in The Lancet.
A new phase 2 clinical trial of 20 infants with spinal muscular atrophy found that the drug nusinersen was safe and improved muscle function and nerve activity in most of the infants. The results have prompted a larger phase 3 clinical trial.
The researchers found that muscle skills improved in 16 of the 20 infants, with the biggest improvements seen in the ability to grasp, kick, and sit. Overall muscle function improved in 14 of 18 babies. Four of the patients in the trial died of the disease during the study, including one who died too early to be included in the final analysis. All the infants experienced issues associated with their disease, and 16 had 77 adverse events such as difficulty breathing or respiratory infections. Those complications were considered by the investigators not to be drug-related, however. One infant developed mild neutropenia and another had mild vomiting possibly linked to the drug.
"While our results are promising, this drug does not represent a cure. We observed remarkable improvement in muscle function -- for instance, some babies undergoing treatment developed the ability to sit and roll over independently, and improved their head control, kicking, grasping, standing, and even walking," lead author Richard Finkel, MD, of the Nemours Children's Hospital in Orlando, Fla., said in a journal news release. However, "although this type of improvement has not been observed before in infants with infantile-onset spinal muscular atrophy, the drug did not restore normal levels of muscle function."
Disclosure: The study was funded by Ionis Pharmaceuticals and Biogen, the manufacturers of nusinersen.
Finkel R, Chiriboga C, Vajsar J et al. Treatment of infantile-onset spinal muscular atrophy with nusinersen: a phase 2, open-label, dose-escalation study. The Lancet. 2016; doi:10.1016/s0140-6736(16)31408-8.