Merck & Co., Inc. (NYSE: MRK)

Merck & Co., Inc. is a global health care company that delivers innovative health solutions through its prescription medicines, biologic therapies, vaccines and animal health products. The company operates principally on a product basis and serves both human and animal health markets worldwide. As of December 31, 2025 it employed approximately 75,000 people across its operations.

Merck generates revenue primarily from the sale of human health pharmaceutical and vaccine products as well as animal health pharmaceuticals vaccines and health management solutions. In 2025 total company sales amounted to $65,011 million with pharmaceutical sales of $58,142 million and animal health sales of $6,354 million. Within the pharmaceutical segment the top selling products were Keytruda at $31,680 million Gardasil or Gardasil 9 at $5,233 million Januvia or Janumet at $2,544 million and ProQuad or M-M-R II or Varivax at $2,451 million. The company also earns alliance revenue from collaborations such as Lynparza and Lenvima which contributed $1,450 million and $1,053 million respectively in 2025. Animal health sales were divided between livestock products at $3,896 million and companion animal products at $2,458 million. Other revenues primarily comprising miscellaneous corporate revenues and third party manufacturing arrangements contributed $515 million in 2025.

The company operates through the following segments: Pharmaceutical and Animal Health.

• Pharmaceutical: This segment includes human health pharmaceutical and vaccine products. Human health pharmaceutical products consist of therapeutic and preventive agents sold by prescription for the treatment of human disorders. Human health vaccine products consist of preventive pediatric adolescent and adult vaccines. Key franchises in this segment include oncology led by Keytruda immunology vaccines such as Gardasil ProQuad Vaxneuvance hospital acute care products like Bridion and Prevymis cardiometabolic and respiratory treatments including Winrevair Adempas Verquvo and Ohtuvayre virology agents such as Lagevrio Isentress Delstrigo and Pifeltro neuroscience products like Belsomra and diabetes treatments including Januvia and Janumet. In 2025 the pharmaceutical segment generated $58,142 million in sales.

• Animal Health: This segment discovers develops manufactures and markets a wide range of veterinary pharmaceutical and vaccine products health management solutions and services and digital identification traceability and monitoring products. It serves livestock and companion animal species with products such as antibiotics vaccines parasiticides fertility management tools and nutrition supplements. In 2025 the animal health segment generated $6,354 million in sales with livestock products accounting for $3,896 million and companion animal products for $2,458 million.

Merck holds a leading position in the global pharmaceutical industry competing with other large research based companies generic manufacturers and specialized animal health firms. Its competitive advantages arise from a robust research and development pipeline a diversified portfolio of patented products strategic alliances and collaborations and extensive global manufacturing and distribution capabilities. The company invested heavily in R&D with approximately 24,700 employees engaged in research activities as of December 31, 2025 and maintains a broad clinical pipeline spanning oncology cardiovascular metabolic infectious diseases neuroscience immunology ophthalmology respiratory diseases and vaccines.

The company’s customers include drug wholesalers and retailers hospitals government agencies managed health care providers such as health maintenance organizations and pharmacy benefit managers physicians veterinarians distributors animal producers farmers and pet owners. Specific customer names are not disclosed in the filing.