Covington & Burling said this week that it is launching a Boston office this spring with "broad-based life sciences capabilities," another sign of Am Law 100 law firms—and their clients—flocking to the city for its biotech opportunities.

"We have seen more and more of our Big Pharma clients relocating operations to Boston," said Covington chair Doug Gibson. "That combined with just the level of expertise out of the great universities in Boston has also created sort of, more of a biotech and emerging company hub for life sciences. So when you combine those two factors, it's just, it's a more and more important market for life sciences."