ISIS-SMNRx is a new drug being developed by ISIS Pharmaceuticals with the goal of reducing the severity of spinal muscular atrophy (SMA) in infants. Classified as an antisense oligonucleotide, ISIS-SMNRx works by affecting the splicing mechanism of RNA. The phase I study showed no adverse events for patients involved. The new therapy will now move on to phase II trials.
In an open-label study involving 17 patients, the therapy showed signs of effectiveness. Some treated infants had longer event-free stretches of time compared with historical averages for victims of the disease. There were also notable improvements in motor control and strength. The most promising result from the open-label study came when a few children gained the ability to sit upright without support. This seemingly simple activity was enough to change their prognoses from type-1 SMA to type-2 SMA.