Judging solely by appearances, Stephen Hahn, the former head of the US Food and Drug Administration, has left Washington behind. Sitting down for an interview at the offices of Flagship Pioneering above the Charles River in Cambridge, Mass., Hahn wears a stylish T-shirt underneath a smartly trimmed suit – a far cry from the DC uniform of repp ties and button-down collars that he wore during briefings as President Trump’s COVID-19-era commissioner.
But when Hahn talks, his observations and motivations often sound political. Why did he join Flagship, where he now serves...






