Lawmakers are finally demanding an investigation into the soaring cost of life-saving allergy medication EpiPen

The sharply rising cost of EpiPens for people with allergies is prompting law makers to demand an investigation of the medicine’s manufacturer, Mylan.

EpiPens went from costing pharmacies less than $100 for a set (two pens) in 2007 to $461 for a set in May of last year and rose again to $608.61 this May, The New York Times reported. The drug contained in the single-use pens, epinephrene, is an emergency medical treatment for severe allergic reactions to foods, bites and stings, latex, medications, and other allergens.

It’s the latest example of a pharmaceutical company raising prices with seemingly little oversight and potentially disastrous consequences for people relying on the treatment. Last year, Martin Shkreli, C.E.O. of Turing Pharmaceuticals, raised the price of Daraprim, a drug used by AIDS and cancer patients, by 5000%. Previously, pharma giant Gilead faced a Senate investigation after pricing its Hepatitis-C medication Sovaldi at $84,000 for a 12–week course of treatment.

Parents feeling the cost of the price increase of EpiPens created an online petition for Mylan to reduce the drug’s cost (which as of Tuesday morning has 9,123 signatures) and took to Twitter to express their concerns:

Senator Chuck Grassley, chair of the Senate Judiciary Committee, wrote to Mylan’s C.E.O., Heather Bresch, on Monday asking for an explanation of the drug’s price hike since the company bought out rights to the drug in 2007. He expressed his concerns over the implications of price increase:

Senator Richard Blumenthal, D.-Connecticut, echoed the same sentiments in a letter blasting the “exorbitant price increases” of the EpiPen:

There is no direct competitor to the EpiPen on the market, but vials of epinephrene are available separately and can be administered with a syringe. But it’s a process that takes more training and precision than using an EpiPen, which uses an auto-injector with a preset amount of the drug. At least 10 states have begun to train more Emergency Medical Technicians to use those syringes because of the rising cost of EpiPens, The Week reported.

“The price of the auto-injector has become a real issue, particularly for the small rural agencies,” Dr. Peter Taillac, chair of the medical directors council of the National Association of State EMS Officials, told the magazine.

Mylan issued a statement to the Times saying health insurance plans with high deductibles were to blame if people are paying more for the drug. They told the paper that because they offer a $100 coupon, very few people would have to pay anything for the drug out-of-pocket. But as the paper points out, the actual cost that consumers pay for EpiPens varies widely depending on their insurance and pricing at the particular pharmacy they buy from.

More than 50 million Americans have allergies, according to the Centers for Disease Control and Prevention. While there’s no clear number of people who die from anaphylaxis–an extreme allergic reaction–each year, a Yale study of death certificates from 1999 to 2010 found that allergies to medication caused 58.8% of allergy-related deaths. That was followed by unspecified anaphylaxis (19.3%), venom (15.2%) and food (6.7%). The study also found that black Americans are disproportionately affected by fatal anaphylaxis: they were more likely to have died from an allergic reaction over that period.