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Merck is a large drug company that researches, makes, and sells medicines and vaccines to treat and prevent serious diseases.
Merck is one of the world's biggest drugmakers, and its business comes down to one thing: discovering medicines and vaccines, getting them approved by regulators, and selling them to hospitals, doctors, and patients around the world. People don't buy Merck products because they like the brand—they buy them because they treat cancer, prevent infections, or keep chronic conditions in check. The company spends billions each year on research, and the payoff comes years later when a drug wins approval and starts selling.
The star of the show is cancer. Merck's immunotherapy drug Keytruda, which helps the body's immune system attack tumors, has become one of the best-selling medicines on the planet and drives a huge share of the company's growth. Merck also sells a large portfolio of vaccines—including Gardasil, which protects against viruses linked to several cancers—plus treatments for diabetes and animal health products for pets and livestock. It even sells medicine directly to patients through a separate health business that fills prescriptions by mail. Its biggest problem is what the industry calls a "patent cliff." Keytruda's U.S. patent protection runs out around 2028, which means cheaper copycat versions could flood the market and take a big bite out of revenue. That's why Merck has been spending heavily to build the next generation of drugs: it bought the biotech company Acceleron to add rare-disease medicines, paid about $11.5 billion for Prometheus Biosciences to deepen its immunology pipeline, and struck licensing deals to bring new cancer treatments into its portfolio. In 2023 it also bought the biotech Seagen—a roughly $11 billion deal—to add antibody-drug conjugates, a promising class of targeted cancer therapy. Its main rivals are fellow drug giants like Pfizer, Bristol-Myers Squibb, and Johnson & Johnson.
Merck is a cash machine. It generated around $19 billion of free cash flow in 2023, money it uses to pay a healthy dividend, buy back shares, and fund expensive research and acquisitions. The bet is simple and risky at the same time: replace a blockbuster that made the company rich with new drugs that can do it all over again before the old one loses its edge.
Saved answer · last researched 23 Oct 2026