Mayne Pharma Alleges Perrigo’s Proposed Topical Product Infringes on Lexette Patent

Mayne Pharma LLC is suing generic drug manufacturer Perrigo over alleged infringement of the plaintiff’s patent covering drug product Lexette.

According to Thursday’s complaint filed in the District of Delaware, the plaintiff is the sole assignee of United States Patent No. 10,857,159, entitled “Halobetasol Foam Composition and Method of Use Thereof,” which covers Lexette, a topical used to treat skin conditions such as psoriasis. The U.S. Patent and Trademark Office issued the patent Dec. 8, 2020, to Robert T. Gauthier and James D. Hammer, the complaint noted.

Defendants Perrigo Israel Pharmaceuticals Ltd. and Perrigo Co. PLC filed Abbreviated New Drug Application (ANDA) No. 215266 seeking approval by the U.S. Food and Drug Administration (FDA) to bring 0.05% halobetasol propionate topical foam, a generic version of Lexette, to market, according to the complaint. The plaintiff claimed that by submitting the ANDA, the defendants have stated their intention of manufacturing, selling, and distributing this product in Delaware and other retail locations globally before the expiration of the patent-in-suit.

The defendants notified the plaintiff that they had submitted the ANDA to the FDA by a letter dated March 16, arguing that the plaintiff’s patent is “unenforceable, invalid, and/or not infringed” by the proposed ANDA product. The letter did offer the plaintiff access to portions of the ANDA pursuant to specific terms set by an Offer of Confidential Access (OCA); however, according to Mayne, the OCA’s restrictions were “unreasonable,” limiting the access to a single law firm and prohibiting Mayne from disclosing other information to consultants or outside counsel. The parties were unable to reach an agreement, so Mayne brought suit.

Mayne claimed that it will be “substantially and irreparably harmed” if the defendants are not enjoined by the court from pursuing their alleged plans to bring to market their ANDA product prior to the patent-in-suit’s expiration. The plaintiff also requested a permanent injunction and an award for damages, and other relief.

K&L Gates LLP represents Mayne.