Martin Shkreli, former chief executive officer of Turing Pharmaceuticals AG, arrives at federal court in the Brooklyn borough of New York, on Monday, July 31, 2017.

A federal appeals court on Thursday upheld the criminal conviction of notorious "pharma bro" Martin Shkreli.

The three-judge panel in the U.S. Court of Appeals for the Second Circut also upheld the more than $6.4 million in foreiture that a judge imposed on Shkreli last year when she sentenced him for his conviction on two counts of securities fraud and one count of conspiracy to commit securities fraud.

Shkreli, 36, is serving a seven-year sentence in a federal prison in Pennsylvania.

In its ruling, the appeals panel disagreed with Shkreli's claim that his trial judge's instructions to the jury at his trial were incorrect and confusing to jurors.

"The instruction given here correctly stated the law," the appeals panel said in its decision. " As such, we disagree with Shkreli that exclusion of additional language describing an element not required for the charged crime constituted a prejudicial error."

The panel likewise dismissed Shkreli's argument that the forfeiture amount was inappropriate because not all of the investors in his hedge funds testified, that they amount should be reduced to account for losses he incurred by making trades for the funds, and that the large returns seen by investors should reduce the forefeiture to zero.

Shkreli's appeals lawyer, Mark Baker, told CNBC, "We're obviously disappointed, and we will consider and weigh whatever remedies are available."

Baker said he did not think he would ask the entire Second Circuit to review the panel's decision, because "I don't think we have a good faith basis" for such a request.

But he will consider whether to ask the U.S. Supreme Court to hear an appeal of the ruling, he said.