The company, which was nurtured by Flagship VentureLabs, the startup unit at Flagship Ventures in Cambridge, was working on a new drug in a medical field focused on the human microbiome — rebalancing bacteria in the body to help it fight off illness. It had developed a pill to treat recurrent Clostridium difficile infections, an especially nasty bug known as C. diff that kills as many as 29,000 people in the United States each year.
Early clinical tests were small but compelling. The treatment cured 29 of 30 patients and the Food and Drug administration gave it breakthrough experimental drug status — which helps speed a drug to market — about two weeks before the company’s IPO.