Ionis Pharmaceuticals is a biotechnology company that discovers and develops RNA-targeted medicines for serious diseases. Its core technology is antisense oligonucleotide (ASO) therapy — short, chemically modified RNA sequences designed to bind to and silence specific messenger RNA targets, addressing the root molecular cause of a disease. Ionis commercializes medicines through two models: independently marketing select drugs in the U.S., and licensing others to large pharma partners who handle development and commercialization costs in exchange for royalties and milestone payments. Ionis' two independent U.S. launches are TRYNGOLZA (for familial chylomicronemia syndrome) and DAWNZERA (for hereditary angioedema). The most important partnered medicine is SPINRAZA (for spinal muscular atrophy), commercialized by Biogen, which generates royalties in the 11–15% range and is the largest single recurring revenue source. Other key partnered medicines include WAINUA (co-commercialized with AstraZeneca for hereditary TTR polyneuropathy) and bepirovirsen (partnered with GSK for chronic hepatitis B, with positive Phase 3 data in early 2026). Ionis' largest near-term commercial opportunity is olezarsen for severe hypertriglyceridemia, with an FDA decision expected in 2026 and management projecting peak sales exceeding $2B. Revenue is split between product sales and royalties on one hand, and lumpy R&D revenue from partner milestones and license fees on the other. Ionis is currently unprofitable but targets cash flow breakeven by 2028 as its commercial portfolio expands.