The paper reported that 67 percent of Duke's 340B patients had commercial healthcare coverage, while only five percent were uninsured.
In a letter to federal health officials last week, Grassley questioned whether the program intended hospitals to sell 340B drugs to non-charity patients for large profits.
"These numbers paint a very stark picture of how hospitals are reaping sizeable 340B discounts on drugs and then turning around and up-selling them to fully insured patients … in order to maximize their spread," Grassley wrote in a letter to the Health Resources and Services Administration (HRSA), which oversees the 340B program.
Grassley's probe began in September after reporters in Raleigh and Charlotte found that large non-profit hospitals were inflating the price of cancer drugs.
In addition to Duke University Hospital, he also questioned UNC Hospitals and Carolinas Medical Center.
“If ‘non-profit’ hospitals are essentially profiting from the 340B program without passing those savings to its patients, then the 340B program is not functioning as intended,” Grassley wrote to the hospitals.