The acquisition of Tesaro and a codevelopment deal with Merck KGaA has helped double the size of GlaxoSmithKline’s clinical oncology pipeline from eight to 16. Earlier this week, GSK formed an alliance with Germany’s Merck to codevelop and commercialize a bifunctional fusion protein immunotherapy intended to treat multiple cancers. Merck has received an upfront payment of €300 million ($340 million) from GSK and could receive a further €500 million in development milestone payments. The candidate, M7824 (proposed International Nonproprietary Name…