Six top pharmaceutical executives and managers, formerly employed by Insys Therapeutics, Inc., were arrested Thursday on charges that they led a nationwide conspiracy to bribe medical practitioners, including a nurse at a pain clinic in Derby. In a sweeping indictment filed in U.S. District Court in Massachusetts, federal prosecutors charged the former CEO and president of the Arizona-based company, Michael Babich, two former vice presidents, and three other managers with paying kickbacks to practitioners in several states, many of whom operated pain clinics, in order to get them to prescribe a fentanyl-based pain medication. The medication, Subsys, is a powerful narcotic intended to treat cancer patients suffering intense episodes of breakthrough pain. In exchange for kickbacks, the practitioners wrote large numbers of prescriptions for the patients, most of whom were not diagnosed with cancer, the indictment says. Prosecutors also allege that the former executives conspired to mislead and defraud health insurance providers, who were reluctant to approve payment for the drug when it was prescribed for non-cancer patients. One of the 10 practitioners referenced in the indictment is Heather Alfonso, formerly an advanced practice registered nurse (APRN) at the Comprehensive Pain and Headache Treatment Center in Derby, who has pleaded guilty to accepting kickbacks from Insys, through a sham “speakers’ program,” in exchange for prescribing Subsys.