Amgen’s $11 Billion Transfer Pricing Dispute Draws Investor Suit

An investor is suing Amgen Inc.'s leaders over the company’s $10.7 billion fight with the IRS, which has said the biopharmaceutical giant dodged a huge tax bill by shifting profits to a subsidiary.

The shareholder lawsuit filed under seal widens the fallout from Amgen’s transfer pricing policies, which drew the scrutiny of regulators who found, after an extensive audit, that the company wrongfully allocated billions to a subsidiary in Puerto Rico, reducing its effective tax rate to 12.5%—well below the drug industry average.

The government’s bid to recoup nearly $9 billion in back taxes and $2 billion in penalties is ...