Nathan Bomey

USA TODAY

Drugmaker Mylan said Monday that it will offer a generic version of the life-saving allergy treatment EpiPen for half the list price of the brand-name treatment after it became the center of a national controversy over skyrocketing drug prices.

The move marks a sharp shift in Mylan's position after it vigorously defended multiple increases over the years that resulted in a list price of about $600 for a two-pack of the emergency injection treatment, up from about $100 in 2009.

​The generic version of EpiPen "will be identical to the branded product, including device functionality and drug formulation," Mylan said in a statement.

"It's highly unusual for a generic product to come out in this way," Marianne Udow-Phillips, director of the Center for Healthcare Research & Transformation at the University of Michigan, said Monday . "It clearly shows how much pressure Mylan was under. It's still a huge profit margin for them."

The company's decision was revealed hours before Republican and Democratic leaders of the U.S. House Committee on Oversight and Government Reform launched an investigation into EpiPen price increases in a rare show of bipartisanship that underscores the depth of the opposition to Mylan's strategy.

Committee chairman Jason Chaffetz, R-Utah, and ranking member Elijah Cummings, D-Md., requested a slew of documents from Mylan, including details of EpiPen profits and sales, lobbying data, internal cost figures and federal health reimbursement numbers.

Mylan has "a virtual monopoly over the epinephrine auto-injector market," the lawmakers said in a letter to Bresch. "While families and schools are struggling to keep up with your company's unreasonable price increases, Mylan has profited richly from its pricing strategy."

The committee's letter, which requested a briefing by Sept. 6 and documents by Sept. 12, paves the way for a potential congressional hearing on the matter.

The company will surely cite its decision to introduce an identical generic as reflective of its attentiveness to the public's concerns.

The move could also be viewed as something of a preemptive strike by Mylan, which is facing the prospect of a generic competitor offered by rival Teva Pharmaceutical Industries — although the U.S. Food and Drug Administration recently dealt Mylan's competitor a setback, saying it wasn't ready to hit the market and delaying the drug until at least 2017.

Mylan's generic version will hit shelves within several weeks at a list price of $300 for a two-pack carton in dosages of either 0.15 milligrams or 0.30 mg, the company said. Mylan will continue to sell EpiPen and continue to offer a $300 discount to certain families that qualify for assistance based on their income levels, a solution the company announced last week to assuage the firestorm that had erupted over the dramatic increase in price.

EpiPen maker to offer discounts after price hike firestorm

"We understand the deep frustration and concerns associated with the cost of EpiPen to the patient, and have always shared the public's desire to ensure that this important product be accessible to anyone who needs it," Mylan CEO Heather Bresch said in a statement, calling the move an "extraordinary commercial response."

The announcement "seems like a bold move" and one that helps its public-relations effort, Evercore ISI analyst Umer Raffat said in a research note. But several questions linger, he said, including whether there will be enough supply and whether pharmacy benefit managers will supply the generic or whether Mylan will require patients to pay with cash.

Mylan offers generic EpiPen: What's the difference?

After becoming immersed in controversy over sharp drug price increases, which has enveloped drug companies such as Valeant Pharmaceuticals and Turing Pharmaceuticals, Mylan took steps to offer discounts to families that needed financial assistance to afford EpiPen. EpiPen is used to treat sudden allergic reactions.

Bresch had blamed the "broken" health-care industry, saying that it "incentivizes higher prices" through a complex thicket of drug companies, insurers, health-care providers and pharmacy benefit managers.

But the price cut illustrates the unilateral pricing power that drug companies retain in certain instances.

Despite the controversy, Mylan shares barely budged Monday. Mylan (MYL) rose 0.4%, 19 cents, to close at $43.22.

"Because of the complexity and opaqueness of today's branded pharmaceutical supply chain and the increased shifting of costs to patients as a result of high deductible health plans, we determined that bypassing the brand system in this case and offering an additional alternative was the best option," Bresch said. "Generic drugs have a long, proven track record of delivering significant savings to both patients and the overall health care system."

Financially, the company could take a hit. Sanford Bernstein analyst Ronny Gal estimated that Mylan would reap 25% less revenue per prescription because of the brand-name discounts and generic competitor.

Mylan is likely to "get some credit for the sharp moves," Gal said in a note to investors — "not absolution, but some recognition they responded."

Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.