Company under fire for opioid marketing files patent suit

An Arizona-based pharmaceutical company targeted in lawsuits and criminal investigations over its marketing of a highly addictive painkiller has filed a related patent-infringement lawsuit against a rival drug maker.

Insys Therapeutics filed the complaint against Teva Pharmaceuticals on Wednesday in federal court in Delaware.

The lawsuit alleges that Teva intends to manufacture and sell a generic version of a fentanyl oral spray before patents held by Insys for its Subsys synthetic opioid spray expire.

Subsys is approved only for acute, persistent cancer pain, but Insys has been accused of marketing it for other uses and bribing doctors to prescribe it to patients who didn't need it, including those without cancer.

In the latest in a series of lawsuits against Insys, Arizona's attorney general accused the company of fraud last month.