Tillman Gerngross came to Dartmouth 15 years ago desperate for a new start. A biochemical engineer in his mid 30s, he’d just watched seven prime career years go by with little but wasted time, a narrow set of skills, and a few tough life lessons to show for it.

As it turns out, it wasn’t too late for Gerngross to find his calling. He’s used his Hanover, NH, perch to go from an assistant professor to one of biotech’s most respected and successful scientific entrepreneurs. He did something no one thought he could do—make protein drugs from yeast—and turned it into a $400 million payday from Merck. He followed that up by creating a self-sustaining, privately held, dividend paying biotech, Adimab. And now, with the same fearless, in-your-face gusto he’s become known for along the way, he’s taking on university politics and trying to upend decades-old tech transfer practices at Dartmouth.

“People have said of me that I don’t suffer fools lightly,” he says. “I’m sure some people dislike that.”

But Gerngross wasn’t always so self-confident. He stepped onto MIT’s campus as just another youngster wondering if he could hack it with the best engineers in the world. As a young scientist, he can remember the humbling days when he couldn’t get peers to approve his grant requests. Like many entrepreneurs, he also ruefully remembers what it was like to pour his heart and soul into his first startup, GlycoFi, taste success, and then watch his baby get suffocated by the Big Pharma machine.

The mistakes made, the obstacles overcome, the lessons learned all contribute to the irrepressible biotech entrepreneur Gerngross is today. Gerngross, at 50, has become the linchpin of a small, but growing biotech network out of New Hampshire. He still has his academic lab at Dartmouth that does research into biochemical engineering. He does some venture capital consulting. His antibody drug discovery shop, Adimab, was valued last year at more than half a billion dollars.