Executives from seven pharmaceutical manufacturers will testify about drug pricing practices before the Senate Finance Committee "one way or another," Sen. Ron Wyden, D-Ore., said Tuesday.

Wyden and Sen. Chuck Grassley, R-Iowa, on Monday sent letters asking for representatives from the seven major drugmakers to testify at a Feb. 26 hearing. The seven companies are AbbVie, AstraZeneca, Bristol-Myers Squibb, Johnson & Johnson, Merck, Pfizer and Sanofi.

Calling the pace of drug price increases "unsustainable," Grassley, who is the committee's chairman, said in a statement that he wants pharmaceutical executives to explain how they price these treatments, "whether the status quo is unacceptable" and what can be done to lower costs.

Wyden, the committee's ranking member, followed with a tweet Tuesday that stopped short of threatening to issue a subpoena, indicating that participation at the hearing isn't entirely voluntary. He said the companies "will come before the committee one way or another."

Wyden tweet

Grassley criticized pharmaceutical companies that declined his invitation to testify at last week's hearing about drug prices, adding that several of the companies asked to testify Feb. 26 declined his original request.

"The companies that declined said they would discuss their ideas in private, but not in public," Grassley said at the committee's Jan. 29 hearing. "That is not what I mean when I talk about transparency. So, we will extend the opportunity again in the future, but we will be more insistent the next time."

Wyden said at the time that the committee would use its "power to compel the drug company CEOs to show up" if they don't testify.

Two companies have agreed to send their CEOs to the hearing, a spokeswoman for Grassley said Tuesday. Merck CEO Ken Frazier will attend, a spokeswoman for the company told CNBC. Sanofi is determining whether current scheduling allows CEO Olivier Brandicourt to attend the hearing, a spokeswoman said. AstraZeneca told CNBC that "we are currently reviewing the request and will respond to the Committee in due course."

Lawmakers on both sides of the aisle have demanded something be done to lower drug prices. President Donald Trump has made lowering out-of-pocket costs for patients one of his administration's top priorities. He's expected to address the issue Tuesday night in his State of the Union address.