In the trial, dosing of the first infant will be carried out within the next few weeks, when Isis will receive an $18m milestone payment from its development partner, Biogen Idec.
ENDEAR is the first of several planned trials in a broad and comprehensive late-stage clinical development program for ISIS-SMN.
The company intends to begin a second pivotal trial in children with SMA later in 2014.
Isis Pharmaceuticals chief operating officer Lynne Parshall said the successful advancement of ISIS-SMNRx from a preclinical drug candidate to late-stage studies within just a few years reflects the effectiveness of the company’s strategic alliance with Biogen Idec and the benefit of working closely together with combined expertise, and the support from the SMA community.
"As we continue development of ISIS-SMNRx and initiate the two pivotal studies in infants and children with SMA, we are in the planning stages for clinical studies in additional patient populations," Parshall said.
"The clinical and preclinical data we have generated to date, including data in multiple open-label clinical studies, across multiple measures with ISIS-SMNRx, support the initiation of these studies, which fully assess the safety and efficacy benefits of this experimental treatment."
The randomized, double-blind, sham-procedure controlled thirteen month Phase III ENDEAR trial will enroll around 110 infants diagnosed with SMA.
The trial will evaluate the efficacy and safety of a 12mg dose of ISIS-SMN with a primary endpoint of survival or permanent ventilation, while additional efficacy endpoints are also included in the trial.
ISIS-SMN is designed to alter the splicing of a closely related gene (SMN2) to increase production of fully functional SMN protein.