Pharmaceutical companies are driven by profit. Is that why diseases that kill thousands of people every year have been ignored – even though the cures may already exist? Health editor Sarah Boseley investigates. Plus: Hillary Clinton argues that Europe must curb immigration to stop rightwing populists gaining ground

Neglected diseases kill thousands of people every year, even though the cures may already exist.

How much it costs for pharmaceutical companies to create a new drug is hotly disputed, but recent figures place it at around $2.7bn. So it’s not a cheap business – but successful medicines can net a company astronomical profits.

The Guardian’s Sarah Boseley has been to the Democratic Republic of the Congo (DRC) to find out how the world turned its back on infections and diseases in poor communities, where thousands of people have missed out on cures because they’re not an ‘attractive’ market. And Els Torreele, executive director of the MSF access campaign, explains why she believes big pharma has resisted finding cures for so long.

Also today: from an exclusive interview with the Guardian, Hillary Clinton argues that Europe must curb immigration to stop rightwing populists gaining ground.