GSK plcGSK plc, (an acronym from its former name GlaxoSmithKline plc,) is a British multinational pharmaceutical and biotechnology company with global headquarters in London. Established in 2000 by a merger of Glaxo Wellcome and SmithKline Beecham, GSK is the tenth largest pharmaceutical company and #294 on the 2022 Fortune Global 500, ranked behind other pharmaceutical companies China Resources, Sinopharm, Johnson & Johnson, Pfizer, Roche, AbbVie, Novartis, Bayer, and Merck Sharp & Dohme.