British-Swedish multinational pharmaceutical company AstraZeneca has won a federal court ruling upholding a key patent for its diabetes drug Farxiga (dapagliflozin), according to Bloomberg.

The ruling will stave off threats from cheaper versions of the drug.

Indian pharma company Zydus Cadila conceded infringement, a common tactic that allowed it to focus on arguments that the patent, which expires in October 2025, was not valid.

U.S. District Judge Richard Andrews rejected Zydus’s arguments that the patent should not have been issued because it covers an obvious variation of an old idea, per Bloomberg.

In an opinion issued Friday, Andrews cited factual findings including “specifically the lack of biological data available for the closest prior art” in ruling that Zydus had not presented “clear and convincing evidence of obviousness.”

In 2020, Farxiga had sales of $569 million in the United States, about 2.2% of AstraZeneca’s total revenue and up from $537 million in 2019, per data compiled by Bloomberg.

According to the FDA’s registry of approved drugs, a patent covering Farxiga use expires in March 2040.

The FDA approved Farxiga in January 2014. The drug is one of six “engines” fueling AstraZeneca’s growth through 2025, according to Bloomberg Intelligence analyst Sam Fazeli.

He wrote in a May 18 note, “Farxiga has upside” beyond consensus estimates, “given the potential of its drug class as a whole is overlooked.”

Belonging to the class of drugs called sodium-glucose transport protein 2 (SGLT2) inhibitors, Farxiga “significantly reduces heart-failure rates and blood pressure, and ameliorate diabetic kidney disease,” Fazeli wrote.

He also wrote that Farxiga’s potential heart failure expansion “adds another $3 billion for the class, while chronic kidney disease and fatty liver disease provide further upside.”

Fazeli said Eli Lilly’s Jardiance (empagliflozin) competes within the class, and its cardiovascular label update slowed Farxiga’s sales, but Farxiga’s own label upgrade “has re-energized its growth despite significant price pressure in the class.”

Another Bloomberg Intelligence analyst Michael Shah wrote in August that the sales of Farxiga could reach $4.2 billion in 2025.

Zydus remains a competitor to AstraZeneca, as it is locked with AstraZeneca in two other patent infringement cases, over the cancer drug Tagrisso (osimertinib). Tagrisso is AstraZeneca’s best-selling cancer drug since 2019, according to Fazeli, its largest growth driver through 2025.