Home Business GSK to buy cancer drugmaker Tesaro for $5.1 billion Business GSK to buy cancer drugmaker Tesaro for $5.1 billion By Genpie - December 3, 2018 183 0 Facebook Twitter Google+ Pinterest WhatsApp GlaxoSmithKline has agreed to buy U.S. cancer drug specialist Tesaro for $5.1 billion, marking a major biotech investment by the drugmaker as its seeks to rebuild its pharmaceuticals portfolio.