Ionis Pharmaceuticals, Inc., formerly Isis Pharmaceuticals, Inc., is engaged in discovering and developing ribonucleic acid-targeted (RNA-targeted) therapeutics. The Company operates through two segments: Ionis Core and Akcea Therapeutics. The Company's Ionis Core segment is developing a drug discovery platform. The Company's Akcea Therapeutics segment consists of the operations of its subsidiary, Akcea Therapeutics, Inc., which develops and commercializes drugs for cardiometabolic disorders. The Company is developing transformational drugs, which include nusinersen, IONIS-TTR and volanesorsen that are designed to treat patients with orphan diseases. In addition to its Phase III programs, the Company has a pipeline of drugs in Phase II development, which includes IONIS-FXI and IONIS-APO(a)-L. Its Phase II pipeline includes drugs to treat patients with severe and rare diseases, viral infections, ocular diseases, metabolic disorders and cardiovascular diseases.