Arrowhead Pharma signs $250M deal

California-based Arrowhead Pharmaceuticals, which has most of its employees in Madison, has signed a $250 million deal with Janssen Pharmaceuticals that could grow to $3.7 billion, according to media reports.

Janssen, a unit of Johnson & Johnson, would develop and commercialize Arrowhead’s latest product, according to MarketWatch. The company is developing a three-injection regime designed to treat hepatitis B. Early tests have indicated a positive response.