Eagle Pharmaceuticals asserts new patents with trio of lawsuits over cancer drug
Complaints say Slayback, Apotex and Baxter Healthcare infringed two patents through NDAs for leukemia drug injection | Eagle patents issued in last two months expire in 2031.
US pharmaceutical company Eagle has filed lawsuits against rivals Slayback Pharma, Apotex and Baxter Healthcare, alleging that they have infringed two recently granted patents covering a leukaemia treatment injection.
The oncology specialist filed its complaints in the Delaware district court on Wednesday last week (January 17), asserting that the three companies had infringed US patents 11,844,783 and 11,872,214 through new drug applications (NDAs) launched in 2022 for bendamustine hydrochloride.
This came the day after a US federal appeals court affirmed a 2022 decision by the Delaware federal court that Slayback and Apotex had not infringed another Eagle patent, US number 11,103,483, granted in 2021 and entitled “Formulations of Bendamustine”.
Eagle’s ‘783 and ‘214 patents, both also entitled “Formulations of Bendamustine”, were issued on December 19, 2023 and January 16 of this year respectively.
They are listed in the US Food and Drug Administration’s (FDA) Orange Book in connection with Belrapzo, an alkylating drug used to treat patients with leukemia and non-Hodgkin lymphoma, and Bendeka, a product marketed by Teva under a license from Eagle. Both patents are set to expire in 2031.
New patents asserted
The FDA granted Slayback, which was acquired by Azurity in 2023, Apotex and Baxter Healthcare approval for their bendamustine hydrochloride products in December 2022.
According to Eagle’s complaint, Slayback has “actively induced infringement” of the patents-in-suit by the marketing and sale of its product Vivimusta, which “relies on data from bioavailability and/or bioequivalence studies contained in the approved labelling for Belrapzo”.
Apotex’s NDA product, a bendamustine hydrochloride injection, was listed on its US website as “therapeutically equivalent to Belrapzo”, Eagle said.
In the suit against Baxter, Eagle alleged the approved labelling of Baxter’s bendamustine product “encourages, recommends, instructs, and/or promotes administration to patients with chronic lymphocytic leukemia”.
The day after the complaints were filed (January 18), Eagle issued an update saying it intended to “seek lost profits and other damages from any and all infringing sales of the defendants’ bendamustine products, as well as injunctive relief requiring the defendants to cease all sales of their infringing products until the expiration of the patents in 2031”.
Michael Graves, interim principal executive officer and interim executive chairman of the board of Eagle, said: “We are pleased to maximise our intellectual property for the bendamustine franchise and will continue to take appropriate steps to enforce our rights related to the newly issued patents.”
‘Unable to establish’ infringement
In the cases regarding the ‘483 patent back in 2022, Eagle alleged that Slayback and Apotex infringed certain claims which covered a “ready to use liquid bendamustine-containing composition”. The defendants denied infringement on the basis that the patent was invalid.
The disputed infringement issue was whether Slayback and Apotex’s proposed products met the ‘ready to use’ limitation of the claims in the ‘483 patent.
It was concluded that ‘ready to use’ meant “able to be dispensed with minimal if any effort or preparation; prepackaged”, and the judge found that Eagle had been unable to establish that the allegedly infringing products met this criteria.
The appeals court affirmed this decision last week.
The cases are Eagle Pharmaceuticals v Apotex, Eagle Pharmaceuticals v Baxter Healthcare, and Eagle Pharmaceuticals v Slayback Pharma. Eagle is represented by Latham & Watkins and McCarter & English.
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