The US Federal Trade Commission (FTC) and the state of New York filed suit Monday against disgraced pharmaceutical executive Martin Shkreli and Vyera Pharmaceuticals for stifling competition to protect the monopolistic pricing of the drug Daraprim (pyrimethamine).

Daraprim is used to treat toxoplasmosis, and despite Vyera Pharmaceuticals being the only Food and Drug Administration (FDA) approved source of the medication, Shkreli and Vyera raised the price of the drug by more than 4,000 percent overnight, from $17.50 to $750 per tablet, after they purchased the rights to Daraprim in August 2015.

New York State Attorney General Letitia James said in a press release that Shkreli and Vyera enriched themselves by “despicably” increasing prices and also held the “critical drug hostage” from patients and competitors as they illegally sought to maintain their monopoly. “We filed this lawsuit to stop Vyera’s egregious conduct, make the company pay for its illegal scheming, and block Martin Shkreli from ever working in the pharmaceutical industry again.”

Daraprim is the only FDA approved drug for the treatment of toxoplasmosis, a parasitic disease which may pose serious and often life-threating consequences for those with compromised immune systems, including individuals with the Human Immunodeficiency Virus (HIV).

The complaint asserts that “Vyera anticipated that its decision to increase the price of Daraprim by more than 4,000 percent would likely encourage entry into the market by other firms, so the pharmaceutical company took specific actions to impede and delay entry by competitors and preserve its monopoly over profits.”

In August 2017 Shkreli was convicted on three out of eight fraud charges and is currently serving a seven-year prison sentence.