In a major change of strategy, the new head of GlaxoSmithKline, Andrew Witty, has told the Guardian he will slash prices on all medicines in the poorest countries, give back profits to be spent on hospitals and clinics and – most ground-breaking of all – share knowledge about potential drugs that are currently protected by patents. Witty says he believes drug companies have an obligation to help the poor get treatment. He challenges other pharmaceutical giants to follow his lead.