Sen. Angus King called out drugmakers suing to prevent a Trump administration rule requiring them to include list prices in their TV ads.

Drug manufacturers Amgen, Merck and Eli Lilly teamed up with the Association of National Advertisers to challenge the rule making drugmakers put list prices in ads. The suit was filed Friday in federal court against the Department of Health and Human Services and the Centers for Medicare and Medicaid Services.

King has been a proponent of more drug pricing transparency, and drug pricing legislation has become a prerequisite for Democrats running to win the 2020 presidential nomination. In a Monday tweet, King highlighted the suit and his push for transparency.

[2020 Democratic contenders largely align on drug price bills]

“It’s commonsense: if you advertise a product to the American people, you should tell them what you’re charging,” the Maine independent said in a tweet Monday. “Apparently drug companies missed the memo, though — they’re suing to block a rule I have been pushing for which requires them to disclose their prices in TV ads.”

It’s commonsense: if you advertise a product to the American people, you should tell them what you’re charging. Apparently drug companies missed the memo, though — they’re suing to block a rule I have been pushing for which requires them to disclose their prices in TV ads. https://t.co/9qUbzhLVMr

— Senator Angus King (@SenAngusKing) June 17, 2019

The move to sue was widely expected after drugmakers warned that the rule violated their First Amendment rights when the proposal was unveiled in October. They also note that almost no one pays the list price, which functions as a starting point for negotiations with health insurers.

“Not only does the rule raise serious freedom of speech concerns, it mandates an approach that fails to account for differences among insurance, treatments, and patients themselves, by requiring disclosure of list price,” Amgen said in a statement. “Most importantly, it does not answer the fundamental question patients are asking: ‘What will I have to pay for my medicine?’”

At least one drugmaker, Johnson & Johnson, embraced the rule early in March by including the list price for its blood thinner Xarelto in its commercials. But other pharmaceutical companies placed prices on their websites instead, in an attempt to address growing scrutiny about the industry’s closely guarded pricing practices. The Pharmaceutical Research and Manufacturers of America launched a digital hub for drug prices in response to the rule.

[House, Senate panels begin hearings seeking drug cost solutions]

In a May press release, King introduced the legislation requiring that list prices be included in advertisements, saying the rules would be cosponsored by Illinois Democrat Dick Durbin and Republican Sens. Chuck Grassley of Iowa and Lamar Alexander of Tennessee. 

In a subsequent Monday tweet, King pointed out the broad support from Republicans and President Donald Trump’s administration. 

“This rule has bipartisan Congressional support, is backed by the administration, and will reduce costs for Americans who rely on these medications,” King said. “If anything, the objections of these corporations makes me think we’re on the right track.”

Lauren Clason contributed to this story.