The founder of embattled fentanyl manufacturer Insys Therapeutics is no longer a billionaire. : The founder of embattled fentanyl manufacturer Insys Therapeutics is no longer a billionaire. Five years after joining the Forbes Billionaires list, John Kapoor now has a net worth of $875 million. Kapoor's fortune is mostly comprised of his stakes in Insys Therapeutics and generic drug manufacturer Akorn Inc., whose shares fell 24% on Friday after a Delaware judge allowed German drugmaker Fresenius to officially terminate its merger agreement with the Lake Forest, Ill.-based company.