Sanofi to Pay Dren Bio Up to $1.8 Billion in Autoimmune Drug Bet

Sanofi agreed to pay US biotech Dren Bio as much as $1.8 billion, including $100 million upfront, as the French company expands a push to develop medicines for immune-system diseases.

The two companies will use closely held Dren Bio’s platform to discover new drug candidates which Sanofi will then develop and commercialize, according to a statement Monday. The terms are largely made up of conditional payments to Dren Bio dependent on the experimental medicines reaching certain milestones.

The deal comes as Sanofi works to bring another blockbuster medicine to market that could help it replace revenues from its top-selling medicine ...