GSK to buy US cancer drug developer amid pressure from activist investor

GlaxoSmithKline's 1.5bn Sierra Oncology deal comes after pressure from Elliott to boost its pipeline

The UK drug company GlaxoSmithKline has agreed a 1.5bn deal to buy a US cancer treatment developer, Sierra Oncology, as it tries to fend off pressure from the activist shareholder Elliott Management.

The deal will give Britain's second-largest pharmaceutical company access to California-based Sierra Oncology's momelotinib, a drug being tested on anaemic patients with a type of bone marrow cancer called myelofibrosis. GSK said the drug had significant growth potential" and it expected sales to start next year, with one analyst predicting it could generate peak annual sales of about $1.7bn (1.3bn).