At a breakfast meeting two-and-a-half years ago, Pascal Soriot, the newly minted chief executive of pharmaceutical giant AstraZeneca, shook hands on the first major drug-development deal of his tenure. It was a research partnership with little-known biotechnology company Moderna Therapeutics of Cambridge, Massachusetts. Worth up to US$420 million, the deal was unusually large for a start-up that offered only a fledgling drug technology, especially one that had not yet even been tested in humans.