ToplineChief executives from three major pharmaceutical companies will testify before a Senate committee on Thursday, following a back-and-forth with Sen. Bernie Sanders (I-Vt.), who has accused the firms of overcharging Americans for prescription drugs.Johnson & Johnson and Merck have accused Sen. Bernie Sanders of unjustly targeting the companies.getty Key FactsJohnson & Johnson CEO Joaquin Duato, Merck CEO Robert Davis and Bristol Myers Squibb CEO Chris Boerner will testify before the Senate Committee on ...