Isis Pharmaceuticals, Inc. has earned a $3.5 million milestone payment from Biogen Idec associated with the dosing of the first patient in a phase II study of ISIS-SMNRx in infants with spinal muscular atrophy (SMA).

The phase II study of ISIS-SMNRx is an open-label, multiple-dose, dose-escalation pilot study, which will include eight infants who have been diagnosed with SMA. To meet enrollment criteria, infants must be between the ages of three weeks and seven months, live in close proximity to a study site and pass screening evaluations conducted at study sites.

The study will be conducted at centres in the United States and Canada.

ISIS-SMNRx is designed to alter the splicing of a closely related gene (SMN2) to increase production of fully functional SMN protein. The United States Food and Drug Administration (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 license the compound until completion of the first successful phase II/III study. ISIS-SMNRx is currently being evaluated in a phase Ib/IIa multiple-dose, dose-escalation study in children with SMA. In this study, children will either receive two or three doses of ISIS-SMNRx over the course of the study.

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

Isis is exploiting its leadership position in antisense technology to discover and develop novel drugs for its product pipeline and for its partners.