Amgen is a biotechnology company built on treatments for cancer, bone disease, inflammatory conditions and rare diseases, several of which have remained top sellers for many years after launch. The company was an early pioneer of biologic drugs, medicines manufactured from living cells rather than chemically synthesized, and that early lead built a manufacturing and regulatory expertise that newer entrants still have to develop. Amgen has increasingly turned to acquisitions to refresh its pipeline as some of its older blockbuster drugs face biosimilar competition, the biologic equivalent of generic drugs. Its obesity drug candidate places it in the same fast-growing category that has reshaped Novo Nordisk and Eli Lilly's growth prospects, though Amgen remains earlier in that race.