The Joseph Saveri Law Firm filed an antitrust class action lawsuit in December 2014 on behalf of California indirect pharmaceutical purchasers against Endo Pharmaceuticals Inc. and Impax Laboratories in the Superior Court in Alameda County. The case was sent to federal court and consolidated with similar cases in the U.S. District Court for the Northern District of Illinois.

Plaintiffs allege that Endo entered into an illegal reverse payment agreement with Impax, paying out more than $100 million in cash in exchange for Impax’s promise to keep generic versions of the painkiller Opana ER off the market for several years.

Purchasers of Opana ER blame the companies for limiting generic competition and enabling Endo to hike prices for Opana ER.

The suit, In re Opana Antitrust Litigation (14-cv-10150, N.D. Ill.), seeks monetary damages for affected consumers.