Arrowhead Pharmaceuticals says it has reached a licensing and collaboration agreement with Janssen Pharmaceuticals that will bring the company $250 million to start and ultimately could be worth as much as $3.7 billion.

Janssen will get the worldwide exclusive license for ARO-HBV, a drug that treats chronic hepatitis B, and an option to collaborate with Arrowhead on drugs aimed at up to three new disease targets.

Arrowhead is based in Pasadena, California, but about 90 of its 110 employees are in Madison, at 502 S. Rosa Road in University Research Park, handling the company’s research and development. Read the full story here.