Isis Pharmaceuticals has earned a $2 million milestone payment from Biogen Idec for the advancement of the ongoing study of ISIS-SMNRx in children with spinal muscular atrophy (SMA). 

The FDA has granted orphan drug status and fast track designation to ISIS-SMNRx for the treatment of SMA. Isis and Biogen are collaborating to develop and potentially commercialize the investigational compound to treat all types of SMA. 

Under the January 2012 agreement, Isis is responsible for global development and Biogen has the option to license the compound until the first successful Phase II/III study or the completion of two Phase II/III studies.