Mirador, a new biotech startup, launches with $400 million

What happens after you close a nearly $11 billion acquisition?

Well, for Prometheus Therapeutics’ former CEO Mark McKenna, there was a brief vacation. But within weeks of the company’s acquisition by Merck closing last June, he was thinking about ideas for the future.

Investors were floating ideas by him. McKenna discussed possibilities with his teenagers and Prometheus’ chief scientific officer. This “summer of discovery,” as McKenna called it, brought him back to the immune system. Prometheus and some other companies have been able to capitalize on creating treatments for conditions like inflammatory bowel disease and psoriasis, while arthritis medications like Humira have brought in billions of dollars in sales. But the field hadn’t quite received the same attention as missions to cure cancer.