NEW YORK-- Billionaire Bill Ackman said his investment firm received a letter from a Senate committee about its investigation into drug prices.
Specifically, the Senate's Special Committee on Aging said it is investigating the pricing of "off-patent drugs," and requested the firm's cooperation, Ackman said. The letter arrived last Friday, Ackman revealed in an annual report to shareholders of his publicly traded entity, Pershing Square Holdings.
"As you would expect, we will fully cooperate with the Committee's request," Ackman said.
Ackman's holding company and hedge fund firm, Pershing Square Capital Management, are major investors in beleaguered drug company Valeant Pharmacuticals. Since the stock peaked last August, it has fallen 87% amid questions about its drug pricing and financial accounting.
Earlier this month, Valeant shed more than 50% of its value in a single day after warning that a late financial filing could lead to bond defaults that may hurt the company's ability to borrow money. The loss resulted in a more than $1 billion loss to Ackman, whose entities own 30.7 million Valeant shares.
This lead, last week, to Valeant's announcement that CEO Michael Pearson would step down and Ackman would join the company's board of directors.
Valeant shares traded down Thursday by another 7% to $31.09 a share, well below the stock's $261 peak reached last August.
Ackman, known for his public feuds with large, publicly traded companies, has is suffering declines of 25% so far this year, on top of losses of 20% this year — thanks in good part to Valeant's decline.
Follow USA TODAY reporter Kaja Whitehouse on Twitter @kajawhitehouse