(Reuters) - U.S. Senator Bernie Sanders is set to question Novo Nordisk CEO Lars Jorgensen on Tuesday over the drugmaker's prices for its popular weight-loss and diabetes medicines that can cost Americans more than $1,000 a month. 

Sanders is expected to challenge the CEO during a hearing of the Senate Committee on Health, Education, Labor and Pensions (HELP), which he chairs, on why the company charges American payors more for the lifesaving drugs than any other country. 

Semaglutide, a drug in the GLP-1 class that is marketed as Wegovy for weight loss and Ozempic for type-2 diabetes, has been shown to help patients lose an average of 15% of their weight.

Ozempic and Wegovy carry U.S list prices of $935.77 and $1,349.02 respectively for a month's supply, which Sanders has previously argued is far higher than the respective $59 and $92 price tags they carry in some European countries. 

Jorgensen said in a written statement sent to the committee that Novo had spent $4.2 billion on diabetes and obesity research and development in 2023 alone.

He said 99% of U.S. commercial insurance plans now cover Ozempic and around half cover Wegovy. More than 80% of U.S. patients with insurance coverage for the drugs pay less than $25 for a month's supply and 90% pay less than $50, he added.

The CEO said Novo Nordisk has committed $30 billion to expand manufacturing capacity since the start of last year, most of which has been directed to GLP-1 drugs, including $4.1 billion to expand its facility in North Carolina last June.

Soaring demand for Ozempic and Wegovy and rival medicines from Eli Lilly ( LLY ) led to shortages of the drugs for much of this year.

Ozempic costs have decreased about 40% since launch while those for Wegovy have similarly declined for payors who receive discounts, Jorgensen said. 

Sanders said earlier this month that generic drugmakers have confirmed they could sell copycat versions of Ozempic for less than $100 a month, and has previously said the high cost of these drugs had the potential to bankrupt the American health system.

Jorgensen said Ozempic will be eligible for U.S. government price negotiations for its Medicare health program in 2027, assuming its meets other legal criteria. The company has previously told analysts it expects Medicare to negotiate the prices of Ozempic and Wegovy for that year.