Vertex Pharmaceuticals said its experimental drug for a rare kidney condition succeeded in a Phase 3 trial, a crucial step in the company's path to diversify beyond its main drugs for cystic fibrosis. The Boston-based drugmaker on Monday said its drug for immunoglobulin A nephropathy, povetacicept, decreased levels of a marker of the autoimmune condition by 52% in a late-stage trial. That passed the bar analysts had set for Vertex's drug to compete with a recently approved treatment from Japan-based Otsuka ...