Isis Pharmaceuticals, a leading company in antisense drug discovery and development, has earned a $9 million milestone payment from Biogen Idec related to advancing the ongoing pivotal phase 3 study evaluating ISIS-SMNRx in infants with spinal muscular atrophy (SMA).

Endear, a phase 3 study of ISIS-SMNRx, is a randomised, double-blind, sham-procedure controlled thirteen month study in approximately 110 infants diagnosed with SMA.  The study will evaluate the efficacy and safety of a 12 mg dose of ISIS-SMNRx with a primary endpoint of survival or time to permanent ventilation.  Additional efficacy endpoints are also included in the study.

ISIS-SMNRx is designed to alter the splicing of a closely related gene (SMN2) to increase production of fully functional SMN protein.  The FDA granted orphan drug status and fast track designation to ISIS-SMNRx for the treatment of patients with SMA.  Isis is currently in collaboration with Biogen Idec to develop and potentially commercialise the investigational compound, ISIS-SMNRx, to treat all types of SMA.  Under the terms of the January 2012 agreement, Isis is responsible for global development and Biogen Idec has the option to licence the compound.  Isis is conducting two phase 3 studies with agreement from the FDA for special protocol assessments, or SPAs. A SPA is a written agreement between the FDA and a drug sponsor intended to confirm that the clinical trial protocol is adequate to meet current scientific and regulatory requirements for a potential new drug application.

Isis acknowledges support from the following organisations for ISIS-SMNRx: Muscular Dystrophy Association, SMA Foundation, Cure SMA and intellectual property licensed from Cold Spring Harbor Laboratory and the University of Massachusetts Medical School.

Biogen Idec and Isis have established four collaborations focused on leveraging antisense technology to advance the treatment of neurological and neuromuscular disorders.  This alliance combines Isis' expertise in antisense technology to evaluate potential neurological targets and discover antisense drugs with Biogen Idec's capability to develop therapies for neurological disorders.  Isis is primarily responsible for drug discovery and early development of antisense therapies.  Biogen Idec has the option to license each antisense program at a particular stage in development.  Current development-stage programs include antisense drugs to treat patients with spinal muscular atrophy (SMA), ISIS-SMNRx, myotonic dystrophy type 1 (DM1), ISIS-DMPKRx, and two undisclosed neurodegenerative diseases, ISIS-BIIB3Rx and ISIS-BIIB4Rx.