Sanders, who chairs the Senate Health, Education, Labor, and Pensions (HELP) Committee, is a fierce critic of both industries and grilled the executives.

Lilly, Novo Nordisk, and Sanofi all said in March they were cutting list prices by more than 70% for some insulin products.

The cuts could help around 2 million people pay for insulin. Although many people, including some 3.3 million on Medicare, pay $35 a month or less, about 1-in-5 with private insurance and the 17% of insulin users who are uninsured stand to benefit.

Uninsured people often have to pay full list prices, an average of $900 a month, forcing many to ration or skip doses.