Merck & Co., Inc. operates as a healthcare company worldwide. It operates through two segments, Pharmaceutical and Animal Health. The Pharmaceutical segment offers human health pharmaceutical products in the areas of oncology, hospital acute care, immunology, neuroscience, virology, cardiovascular, and diabetes under the Keytruda, Bridion, Adempas, Lagevrio, Belsomra, Simponi, and Januvia brands, as well as vaccine products consisting of preventive pediatric, adolescent, and adult vaccines under the Gardasil/Gardasil 9, ProQuad, M-M-R II, Varivax, RotaTeq, Live Oral, Vaxneuvance, Pneumovax 23, and Vaqta names. The Animal Health segment discovers, develops, manufactures, and markets veterinary pharmaceuticals, vaccines, and health management solutions and services, as well as digitally connected identification, traceability, and monitoring products. The company serves drug wholesalers and retailers, hospitals, and government agencies; managed health care providers, such as health maintenance organizations, pharmacy benefit managers, and other institutions; and physicians, wholesalers, government entities, veterinarians, distributors, animal producers, farmers, and pet owners. It has development and commercialization agreement for three of Daiichi Sankyo's deruxtecan ADC candidates, which include patritumab deruxtecan, ifinatamab deruxtecan, and raludotatug deruxtecan for the treatment of multiple solid tumors both as monotherapy and/or in combination with other treatments; and AstraZeneca PLC to co-development and co-commercialize AstraZeneca's Lynparza products for multiple cancer types, and Koselugo for multiple indications. The company also has a collaboration agreement with Eisai Co., Ltd., Bayer AG, and Ridgeback Biotherapeutics LP, as well Moderna, Inc. Merck & Co., Inc. was founded in 1891 and is headquartered in Rahway, New Jersey.