LONDON (Reuters) - GlaxoSmithKline (GSK.L) has bought 5 million newly issued shares in diagnostics firm Response Genetics RGDX.O for $1.10 each, giving it a stake of 15.2 percent and sending shares in the U.S. company sharply higher.
The investment follows a deal between the two firms in 2010 that gave British-based GSK rights to Response's gene mutation testing technology, an area of growing importance to drugmakers as they target treatments according to patients' genetic profiles.
GSK said Response was performing companion diagnostic tests and other related activities for its immunotherapies and oncology pipeline candidates.
Shares in Response jumped 21 percent to $1.09 each in pre-market Nasdaq trading on Thursday.
Reporting by Ben Hirschler; editing by James Jukwey