NEW YORK (Reuters) – U.S. drug company Merck & Co Inc said on Tuesday that its Chief Executive Ken Frazier plans to testify at a Senate hearing later this month examining rising prescription drug prices.

Republican Senator Chuck Grassley, chairman of the Senate Finance Committee, and Democratic Senator Ron Wyden, ranking member of the committee, on Monday invited executives from seven pharmaceutical companies, including Merck, to testify. The other companies are AbbVie Inc, AstraZeneca PLC, Bristol-Myers Squibb Co, Johnson & Johnson, Pfizer Inc and Sanofi SA.

A spokesman from Senator Grassley’s office said on Monday that two of the CEOs have agreed to testify so far, but did not say what companies they were from.