Updated at 3:11 p.m.

Opening statements were heard in Boston’s federal court Monday for the trial of one of the highest-ranked pharmaceutical executives to be charged in the midst of the national drug crisis.

John Kapoor, the one-time billionaire founder of Insys Therapeutics, is accused of offering millions in kickbacks to doctors who wrote large numbers of prescriptions for a fentanyl-based pain medication. The pain medication was approved for cancer patients, but many of those who received prescriptions did not have cancer.

Further, prosecutors contend that Kapoor — and four other top executives who are also on trial — developed a strategy to mislead insurers and ensure they cover the costly opioid medication.

Assistant U.S. Attorney David Lazarus said this is “a case about greed and its consequences and what happens when you put profits above people.” He accused Kapoor’s company of knowingly working with physicians who were known for running pill mills.

Lazarus contended that the company’s sales representatives focused on a small group of physicians who wrote large numbers of prescriptions, paying some doctors more than $200,000. The payments often were in the form of speaker fees for events that were poorly attended and, according to prosecutors, a cover for their kickback scheme.

This trial is part of the federal government’s effort to hold drug company executives responsible for their role in fueling the opioid epidemic. Tens of thousands of people died of overdoses in 2017, and many of those addicted to opioids started using because of a physician's prescription.

Kapoor and the four others have pleaded not guilty. Kapoor’s defense attorney, Beth Wilkinson, placed all blame on Alec Burlakoff, former vice president of Insys, who has already pleaded guilty to a count of racketeering conspiracy and is cooperating with prosecutors.

“All roads to criminal activity lead back to one person and one person only — and that’s Alec Burlakoff,” said Wilkinson.

Wilkinson told jurors that Kapoor’s late wife battled breast cancer, and it was this personal experience that motivated him to develop this pain medication for cancer patients.

Wilkinson also argued that it is unfair to link this one opioid medication, which accounts for a small percentage of all opioid prescriptions, to the national drug crisis.

Judge Allison Burroughs said she’d allotted up to 14 weeks for the trial.