Last December, only weeks after Barack Obama had won the race for the US presidency, Richard Clark, the head of Merck, arranged a meeting with Fred Hassan, his opposite number at Schering-Plough.

In the world of pharmaceuticals, the meeting would mark a significant change of era. The two men’s offices are a few miles apart in New Jersey, historic centre of gravity of the US industry, and their companies have similarities and a history of co-operation.