GlaxoSmithKline is expected to announce a deal to buy Human Genome Sciences for about $2.8 billion as soon as Monday, ending a three-month hostile pursuit of the U.S. biotech company on friendly terms after sweetening its offer. Sources familiar with the situation said Britain's biggest drugmaker was set to pay around $14 per share, up from $13 offered previously, which Human Genome - an early pioneer of gene-based drug discovery - had rejected as inadequate. Biotechnology companies are in increasing demand as Big Pharma companies seek new products to replace older medicines that are going off patent in the biggest wave of drug patent expiries in history.
