AstraZeneca Wins Ruling Upholding Key Patent for Diabetes Drug
(Bloomberg) -- AstraZeneca Plc won a federal court ruling upholding a key patent for its diabetes drug Farxiga, staving off threats from cheaper versions.
A trial without a jury in May centered on the validity of a patent that covers Farxiga’s active ingredient, dapagliflozin, its combination with a carrier and methods of treatment. Zydus Cadila conceded infringement before the trial, a common tactic that allowed it to focus on arguments that the patent, which expires in October 2025, wasn’t valid.
U.S. District Judge Richard Andrews in Wilmington, Delaware, rejected Zydus’s arguments that the patent shouldn’t have been issued because it covers an obvious variation of an old idea.
Andrews, in an opinion issued Friday, cited factual findings including “specifically the lack of biological data available for the closest prior art” in ruling that Zydus hadn’t presented “clear and convincing evidence of obviousness.”
Representatives of AstraZeneca and Zydus didn’t immediately respond to requests for comment on the ruling.
Farxiga had U.S. sales of $569 million in 2020, about 2.2% of Astra’s total revenue and up from $537 million in 2019, according to data compiled by Bloomberg. Its U.S. sales grew by 27% year over year in the first half of 2021, to $302 million, driven by a new indication for heart failure, Astra said July 29 in its quarterly earnings report. A patent covering that use expires in March 2040, according to the FDA’s registry of approved drugs.
The drug, which the FDA approved in January 2014, is one of six “engines” fueling Astra’s growth through 2025, Bloomberg Intelligence analyst Sam Fazeli wrote in a May 18 note. “Farxiga has upside” beyond consensus estimates, he wrote, “given the potential of its drug class as a whole is overlooked.”
Farxiga is in the class of diabetes drugs known as SGLT-2, which also “significantly reduce heart-failure rates and blood pressure, and ameliorate diabetic kidney disease,” Fazeli wrote. The drug group’s potential heart failure expansion “adds another $3 billion for the class, while chronic kidney disease and fatty liver disease provide further upside,” he said.
Eli Lilly’s Jardiance competes within the class, and its cardiovascular label update slowed Farxiga’s sales, Fazeli said. But Farxiga’s own label upgrade “has re-energized its growth despite significant price pressure in the class.”
Thorn in Astra’s Side
Bloomberg Intelligence analyst Michael Shah wrote in an Aug. 30 note that Farxiga’s sales could reach $4.2 billion in 2025.
Zydus in particular remains a thorn in Astra’s side. The generic-drug maker is locked with Astra in two patent infringement cases, both also in Delaware, over the cancer drug Tagrisso, Astra’s best-selling medicine since the start of 2019 and, according to Fazeli, its largest growth driver through 2025.
The Farxiga case is AstraZeneca AB v. Zydus Pharmaceuticals (USA) Inc., 18-cv-664, U.S. District Court, District of Delaware (Wilmington).
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