Pfizer Inc. is a leading research-based biopharmaceutical company that discovers, develops, manufactures, and commercializes innovative pharmaceutical and biological products across multiple therapeutic areas including primary care, specialty pharmaceuticals, oncology, vaccines, cardiovascular and respiratory medicines, and biosimilars. The company generates revenues primarily through direct sales of branded pharmaceuticals to healthcare providers, pharmacies, and pharmacy benefit managers, as well as through sales to government payors like Medicare and Medicaid, international health systems, and vaccines sold to national immunization programs. Pfizer operates globally with a portfolio concentrated in key franchises, including several blockbuster products each generating over one billion dollars in annual revenues, while managing ongoing challenges from patent expirations, generic and biosimilar competition, and pricing pressures from government regulations.