U.S. Sen. Bernie Sanders (I-Vt.) sent letters to Sanofi SA and Novo Nordisk A/S executives on March 1, urging them to follow Eli Lilly and Co.’s example in cutting prices for their insulin products, offering more affordable access for Americans with diabetes. Industry leaders, however, have long argued that the problem goes far beyond list price, as pharmacy benefit managers and health plans have simply not passed their rebates onto consumers.