GlaxSmithKline

British biopharmaceutical group with its head office at Brentford in London, formed in 2000 by the merger of Glaxo Wellcome and SmithKline Beecham and renamed GSK, listed in London and New York, with its consumer health business separated as Haleon in 2022. Discovers, develops, makes and sells prescription medicines and vaccines in infectious disease, HIV, oncology, immunology and respiratory disease, and runs its own research sites, manufacturing plants and non-clinical safety and clinical development laboratories.