BROOKLYN, N.Y.—Four of the nation’s largest pharmacy operators have filed an antitrust lawsuit in U.S. District Court here accusing Allergan plc (NYSE: AGN) of an “unlawful scheme to maintain its monopoly in the market” for dry-eye treatment Restasis in the U.S. The four retailers—Walgreen Co., Kroger Co., Albertsons Cos. Inc. and HEB Grocery Co.—allege antitrust violations by the pharmaceutical company. Allergan could not be reached for comment at VMAIL’s press time, but a spokesman indicated to some media outlets that the company does not comment on pending litigation.

In the lawsuit, the companies claim that “Allergan unlawfully maintained its monopoly [on Restasis] through a scheme that included, inter alia, making material misrepresentations and omissions to the United States Patent and Trademark Office (PTO) that allowed it to obtain patents to which it was not entitled; improperly listing those patents in the FDA’s Orange Book; suing generic competitors for alleged infringement of those invalid and unenforceable patents; and then transferring ownership of the invalid patents to a sovereign Native American tribe in order to avoid judicial scrutiny of the patents.”

In September 2017, Allergan announced that the Saint Regis Mohawk Tribe had taken ownership of all Orange Book-listed patents for the dry eye treatment Restasis, and that Allergan had been granted exclusive licenses in the patents, as VMAIL reported. The Native American tribe, a recognized sovereign tribal government, subsequently filed a motion to dismiss the ongoing inter partes review of the patents “based on [the tribes] sovereign immunity from IPR challenges,” according to Allergan’s announcement at the time.

In the lawsuit filed this week, the four retailers allege that generic Restasis would have been available to U.S. distributors and patients by May 2014 if not for Allergan’s actions.

The plaintiffs are seeking injunctive relief and asking the court to prohibit Allergan from continuing its “illegal conduct,” among other forms of relief. They also are seeking overcharge damages, in an amount to be determined at trial, trebled, according to the lawsuit.