The plaintiff, Roofers Local No. 149 Pension Fund, said Amgen's share price fell 6.5% on Aug. 4, 2021, and 4.3% on April 28, 2022, because the company waited until those dates to disclose its potential liabilities. "Defendants failed to take any meaningful accrual or otherwise reveal the staggering amount of back taxes and penalties claimed by the U.S. government," causing shareholder losses when the truth was revealed, the fund said. Chief Executive Robert Bradway and Chief Financial Officer Peter Griffith are also defendants. Amgen on Tuesday said it was reviewing the complaint.