As a pharmaceutical company run by U.S. Sen. Joe Manchin's daughter faces scrutiny for hiking prices on life-saving allergy injection pens, Manchin is remaining mum.
The Democratic West Virginia senator's daughter, Heather Bresch, is CEO of Mylan, which manufactures EpiPens.
A two-dose package cost around $94 nine years ago. The cost averaged more than six times that in May.
Manchin spokesman Jonathan Kott said Wednesday the senator had no comment.
Several senators are demanding more information and requesting congressional hearings and investigations.
Sens. Amy Klobuchar of Minnesota and Richard Blumenthal of Connecticut want the Federal Trade Commission to investigate Mylan for possible antitrust violations.
Hillary Clinton, whom Manchin has endorsed for president, called the increase "outrageous."
A Mylan statement Tuesday cited health insurance changes with higher deductible costs for many.