The request by the Department of Justice came three days before Shkreli's scheduled sentencing by U.S. District Judge Kiyo Matsumoto in Brooklyn federal court.
Prosecutors called Shkreli "a man who stands before this court without any showing of genuine remorse, a man who has consistently chosen to put profit and the cultivation of a public image before all else, and a man who believes the ends always justify the means."
Shkreli, 34, had requested a 12-to-18-month term following his conviction last August for lying to investors about the performance of his hedge funds MSMB Capital and MSMB Healthcare, and conspiring to manipulate the stock price of the drug company Retrophin Inc <RTRX.O>.
Known as "Pharma Bro," in part for his ability to attract attention, Shkreli is perhaps best known for raising the price of the anti-parasitic drug Daraprim by more than 5,000 percent in 2015, while serving as chief executive of Turing Pharmaceuticals, now called Vyera Pharmaceuticals.
Benjamin Brafman, a lawyer for Shkreli, declined to comment on the government's sentencing request.
Shkreli has been in jail since September, when Matsumoto revoked his bail after he offered social media followers $5,000 for a hair from former U.S. presidential candidate Hillary Clinton.
On Monday, Matsumoto ordered Shkreli to forfeit $7.36 million of ill-gotten gains. She said he may be forced to give up assets such as a Picasso painting and a one-of-a-kind Wu-Tang Clan album if he cannot find the money.
In a letter to the judge last week, Shkreli said he accepted that he had made "serious mistakes," but still considered himself "a good person with much potential."
But prosecutors said that while in jail, Shkreli has privately expressed disdain for his conviction and the judicial process, providing further evidence he does not deserve mercy.
It cited a January email conversation where Shkreli allegedly wrote "fuck the feds" and expressed hope for a big tax refund because only his "liquid money" was affected by the forfeiture.
"Shkreli's email communications confirm that any remorse he may express publicly is a carefully constructed facade," prosecutors said.
A 15-year term is shorter than the minimum 27 years recommended under federal guidelines. Brafman has called that length "draconian and offensive."
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