At the hearing, outrage over drug-pricing once again united politicians from both sides of the aisle. It came months after “pharma bro” Martin Shkreli, former chief executive of Turing Pharmaceuticals, appeared in the same chamber because he had increased the price of a decades-old drug called Darparim from $13.50 to $750 a pill.
"Here we are again, and my guess is if it's happening in these two instances, it's probably happening in others," Chaffetz said during the hours-long hearing. "Maybe not as egregious, maybe not as big of a rapid rise, but I find this to be so extreme."
Proposed solutions included finding ways for the Food and Drug Administration to ease the drug-approval process so competition can help bring down prices and calls for greater transparency in pharmaceutical pricing.
But Heather Bresch, Mylan's chief executive, stayed firm in her message that the list price of EpiPen had increased because of the inherent complexity of the pharmaceutical marketplace and that few patients were paying the list price. She has attempted to shift blame away from her company to a network of middlemen that sits between drug companies and patients and take a cut of the price.
Bresch said that Mylan's efforts to cut down the price patients pay - including its plan to release a half-price generic version of EpiPen - would solve the problem.
It was the second time this week that lawmakers called a chief executive to Capitol Hill to answer for perceived wrongdoings. On Tuesday, Wells Fargo chief executive John Stumpf attempted to address questions about the creation of millions of sham accounts to boost sales.
Bresch has come under scrutiny not only for raising the price of EpiPen but also for the role her mother, Gayle Manchin, played in encouraging states to require schools to stock epinephrine as head of the National Association of State Boards of Education, according to USA Today. Bresch's father is Sen. Joe Manchin III (D-W.Va.).
Mylan acquired the drug in 2007 and raised the price of a two-pack from less than $100 to more than $600 today, which has led to fierce criticism from lawmakers and the public.
"I think many people incorrectly assume we make $600 off each pen. This is simply not true," she said, repeatedly saying that Mylan gets $274 for each sale of a two-pack, and of that $100 is profit.
But lawmakers were clearly frustrated as they struggled to understand how much total profit the company had made and how that had changed as the list price increased.
Rep. Elijah E. Cummings (D-Md.) attempted to break down how much of the $912 million in EpiPen net revenue for Mylan in 2015 represented profit.
"How about this: Would you agree that you made hundreds of millions of dollars in profit in 2015 based on the sale of EpiPens alone?" Cummings asked, clearly frustrated that Mylan had not provided documents to answer the question and requesting that Bresch furnish the information to the committee.
Bresch emphasized that in the eight years Mylan has owned EpiPen, the company has invested to "enhance the product and make it more available," estimating the total investment at more than $1 billion.
For example, in 2009, changes to the device improved it, Bresch said. But those changes also gave Mylan renewed patent protection for EpiPen, insulating it from possible generic competition even though the drug was first approved nearly three decades ago. At the same time, Mylan began a pattern of large, biannual price increases. The efforts that Mylan has made to increase the awareness of anaphylaxis, a life-threatening allergic reaction, has resulted in increased availability of emergency epinephrine in schools but also benefited its bottom line.
While Bresch's testimony and answers stressed Mylan's commitment to providing access to the drug, lawmakers - even those who specifically said that they supported a company's ability to make a profit - were skeptical about the company's tactics.
"As someone who considers themselves to be a free-market Republican, part of me has been uncomfortable with where this hearing has gone," said Rep. Mick Mulvaney (R-S.C.). "But I have to defend both my Republican and Democrat colleagues, because you asked for it. ... If you want to come to Washington, if you want to come to the state capitols and lobby us to make us buy your stuff, this is what you get. You get a level of scrutiny and a level of treatment that would ordinarily curl my hair."
Rep. Tammy Duckworth (D-Ill.) waved a contract that schools could sign to get access to discounted EpiPens, pointing out that a condition of getting the discount was a requirement that schools not buy competitors' products. "You're so concerned about these kids that you limit the schools' ability to buy the pens from anyone else," Duckworth said.
The New York attorney general's office has launched an investigation into whether there are antitrust issues or anticompetitive terms in any of Mylan's contracts with schools.
Also at the hearing was Douglas Throckmorton, deputy director of the Center for Drug Evaluation and Research at the Food and Drug Administration. He was asked questions about the generic backlog but said he could not comment on the number of epinephrine injector products waiting for regulators.
The heat of the hearing was focused on Bresch, who is the latest political punching bag for an issue that is beginning to follow a pattern: A drug company finds itself in the crosshairs for raising the list price. The solution that is usually discussed is encouraging competition.
But as Throckmorton pointed out, four epinephrine autoinjectors have been approved, and two are on the market.
Douglas S. Boothe, president of the generics division at Impax Laboratories, which makes a competitor - the authorized generic of Adrenaclick - said in an interview that his company is ramping up its manufacturing capabilities.
But he noted that since his drug is not considered a true generic of EpiPen, one challenge is that if a physician writes "EpiPen" on a prescription, it cannot be substituted by a pharmacist in more than half of states without rewriting the prescription.
That may be one factor that helps fuel EpiPen's dominance, with a market share of over 90 percent.
"You virtually have a monopoly, and you've used it to your advantage - but unfortunately, it's at the expense of people who need it," said Rep. Gerald E. Connolly (D-Va.). "I'm wondering what your sense of social responsibility is to those people.
Correction: A previous version of this story misstated the profit Mylan makes on EpiPen. It is $50 per pen.