LISTEN TO ARTICLE 1:40 SHARE THIS ARTICLE Share Tweet Post Email

The U.S. Senate’s Special Committee on Aging will investigate drug pricing practices by four drug companies, including Valeant Pharmaceuticals International Inc., in the latest political challenge to an industry under intensifying scrutiny.

The panel, led by Senator Susan Collins of Maine, a Republican, and Senator Claire McCaskill of Missouri, a Democrat, sent letters to the companies asking about why they raised prices on drugs. Along with Valeant, the senators contacted Turing Pharmaceuticals AG, Retrophin Inc. and Rodelis Therapeutics. Daraprim, Turing’s anti-infection drug that increased from $13.50 to $750 per tablet, is of particular interest, the senators said.

“The Senate Special Committee on Aging considers these massive price increases worthy of a serious, bipartisan investigation into the causes, impacts, and potential solutions,” Collins said in a statement. A spokesman for the minority committee staff said McCaskill would support the use of subpoenas if the companies don’t cooperate.

They senators said the committee will hold a hearing on the issue on Dec. 9.

McCaskill had already requested details from Valeant on how it set prices for the drugs Isuprel and Nitropress, and called the company’s response at the time “deeply disappointing.” Collins could add weight to her inquiry by making it bipartisan.

Spokesmen for Valeant and closely held Turing didn’t immediately have a comment. Retrophin and closely held Rodelis didn’t immediately respond to requests for comment.

Retrophin shares fell 11 percent to $19.50 in early trading. Valeant rose 1.4 percent to $99.20.

(Corrects spokesman comment in third paragraph.)