Biogen and Ionis Pharmaceutical signed a collaboration agreement to identify new antisense oligonucleotide drug candidates for the treatment of spinal muscular atrophy (Sma), a disease characterised by loss of motor neurons in the spinal cord and lower brain stem, resulting in severe and progressive muscular atrophy and weakness. Individuals with the most severe type of Sma can become paralyzed and have difficulty performing the basic functions of life, like breathing and swallowing. Under the agreement, Ionis will receive a $25 million upfront payment and will earn development and regulatory milestone payments from Biogen if new drugs advance towards marketing approval.