(CNN) The founder of pharmaceutical company Insys Therapeutics has been sentenced to 5 years and 5 months in prison for overseeing a scheme to bribe medical professionals to use his fentanyl-based medication, federal officials said.

John Kapoor, 76, of Phoenix, and four top Insys executives, were convicted of racketeering conspiracy by a federal jury in May. Kapoor was sentenced Thursday and along with the prison term, he was ordered to pay forfeiture and restitution to be determined at a later date and will be under three years of supervised release. The government recommended a sentence of 15 years in prison.

In November 2019, US District Court Judge Allison Burroughs overturned convictions for Kapoor and three other executives for alleged violations of the Controlled Substances Act and for alleged honest services fraud arising from the executives' part in marketing and selling Subsys.

Subsys is a highly addictive synthetic opioid that was intended to manage cancer pain.

The convictions for mail fraud and wire fraud types of predicate racketeering stood for the five executives.