First-Ever Treatments and a Crushing Setback: The Week Drug Development Showed Its Best and Worst

Ionis Pharmaceuticals won FDA approval Thursday for Zanvastro (zilganersen), the first-ever treatment for Alexander disease — a rare, devastating neurological disorder affecting fewer than 1 in a million people worldwide that can be fatal. The RNA-based drug directly targets the toxic buildup of glial fibrillary acidic protein (GFAP) that destroys neurons and myelin. In a pivotal trial, treated patients' walking speed stayed stable while the control group declined...