Merck & Co., Inc. operates as a healthcare company worldwide. It operates through two segments, Pharmaceutical and Animal Health. The company offers human health pharmaceutical for various areas, including oncology, vaccines, hospital acute care, cardiovascular, virology, neuroscience, and diabetes under the Keytruda, Welireg, Gardasil, ProQuad, M-M-R II, Varivax, Vaxneuvance, RotaTeq, Pneumovax 23, Bridion, Dificid, Zerbaxa, Noxafil, Winrevair, Adempas, Verquvo, Lagevrio, Isentress/Isentress HD, Delstrigo, Pifeltro, Belsomra, Januvia, and Janumet brands. It also provides veterinary pharmaceuticals, vaccines and health management solutions and services, such as livestock products under the Nuflor, Bovilis/Vista, Bovilis Cryptium, Banamine, Estrumate, Matrix, Resflor, Zuprevo, Revalor, Safe-Guard, M+Pac, Porcilis, Circumvent, Nobilis/Innovax, Paracox and Coccivac, Exzolt, Slice, Imvixa, Clynav, Aquavac/Norvax, Aquaflor, Flexolt brands; Allflex Livestock Intelligence solutions for animal identification, monitoring and traceability; and companion animal products under the Bravecto One-Month, Bravecto Injectable/Quantum, Bravecto Plus, Sentinel Spectrum, Sentinel Flavor Tabs, Optimmune, Nobivac NXT, GilvetMab, Otomax, Mometamax, Mometamax Ultra, Posatex, Caninsulin/Vetsulin, Panacur, Regumate, Prestige, Scalibor/Exspot, Sure Petcare, and Home Again brands. The company has development and commercialization agreement for three of Daiichi Sankyo's deruxtecan ADC candidates; AstraZeneca PLC to co-development and co-commercialize AstraZeneca's Lynparza products for multiple cancer types, and Koselugo for multiple indications; licensed to develop, manufacture and commercialize LM-299, a novel investigational PD-1/VEGF bispecific antibody from LaNova; and 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.