Understand any stock in simple English
Enter a ticker to learn what the company does and how it makes money.
Regeneron invents and sells medicines that treat serious eye diseases, skin conditions, asthma, and rare genetic disorders.
Regeneron is a drug company. It discovers, tests, and sells medicines, mostly large-molecule drugs made from living cells rather than simple chemicals. It sells to hospitals, clinics, pharmacies, and insurers, largely through wholesale distributors. One product, Eylea, treats a common cause of vision loss in older people by blocking a protein that makes blood vessels leak. Another, Dupixent, calms the immune system and is used for eczema, asthma, and other allergic conditions. A third big seller, Libtayo, fights certain cancers by helping the immune system attack tumors. Eylea and its newer version are roughly a third of revenue, and Dupixent is a similar-sized chunk.
Think of Regeneron as a factory for antibodies, the body's natural targeting missiles. Its scientists mine huge genetic databases to find which proteins actually cause disease, then engineer copies or blockers of those proteins as drugs. That genetics-first approach is also why it makes ultra-expensive treatments for rare diseases, where a single patient can pay hundreds of thousands of dollars a year. The catch: drugs are protected by patents for only so long. Eylea already faces cheaper copycat versions, which is why Regeneron keeps launching improved formulas and new products.
Regeneron was founded in 1988 in the New York suburbs and is still run by one of its co-founders, Leonard Schleifer. Its most important relationship is with Sanofi, which shares profits on Dupixent and other drugs; that partnership is a huge slice of earnings. The company spends heavily on research, roughly a fifth of revenue, and has recently pushed into new areas like a gene-editing partnership and an antibody for hearing loss. It also buys back its own stock, returning cash to shareholders while keeping plenty on hand for science.
Saved answer · last researched 15 Oct 2026