Biogen

Tysabri (natalizumab) is a monoclonal antibody from Biogen for highly active relapsing forms of multiple sclerosis and, in the United States, for moderately to severely active Crohn's disease after inadequate response to conventional therapy. It keeps inflammatory immune cells out of the brain and gut.

Natalizumab is given by intravenous infusion and works on the traffic of immune cells rather than destroying them. Most white blood cells carry alpha4

Spinraza (nusinersen) is an antisense oligonucleotide from Biogen for spinal muscular atrophy in children and adults. Given into the spinal fluid, it helps the backup SMN2 gene produce more of the survival motor neuron protein that motor neurons need to survive.

Spinal muscular atrophy is caused by a defect in the SMN1 gene, so motor neurons lack survival motor neuron (SMN) protein and gradually stop working,