Amgen is a large-cap biotechnology company that discovers, develops, manufactures, and sells biologic medicines — complex drugs derived from living cells, including monoclonal antibodies and other protein-based therapies — for serious diseases. Amgen operates across four therapeutic areas: general medicine (cardiovascular, bone health, obesity pipeline), rare disease, inflammation, and oncology. Key products include Repatha (PCSK9 inhibitor for LDL-C reduction), Prolia and EVENITY (osteoporosis), TEPEZZA (thyroid eye disease), TEZSPIRE (severe asthma), and a broad oncology portfolio anchored by BLINCYTO and IMDELLTRA. Amgen generates revenue by selling branded biologics at premium prices, with growth driven primarily by patient volume rather than price, as net selling prices face ongoing pressure from payer rebates, PBM negotiations, and government programs including IRA-mandated Medicare price negotiations. Amgen also operates a growing biosimilars business, having launched eight biosimilars since 2018. The U.S. accounts for roughly 73% of product sales, with the majority sold through three wholesale distributors — McKesson, Cencora, and Cardinal Health. Amgen's pipeline is unusually active, headlined by MariTide, a monthly-or-less obesity injection in six Phase III studies, and olpasiran, an siRNA therapy targeting Lp(a) in a cardiovascular outcomes trial. Amgen acquired Horizon Therapeutics in 2023 for ~$28B, adding its rare disease portfolio, and has since prioritized debt repayment alongside heavy R&D and manufacturing investment.