By Blake Brittain

WASHINGTON, July 9 (Reuters) - A U.S. appeals court on Thursday upheld a ruling for AstraZeneca AZN.L against allegations that its blockbuster lung-cancer drug Tagrisso infringed patents owned by Pfizer PFE.N subsidiary Wyeth.

The Washington-based U.S. Court of Appeals for the Federal Circuit agreed with a Delaware federal judge that the two patents Wyeth accused AstraZeneca of infringing were invalid.

Spokespeople for Pfizer and AstraZeneca did not immediately respond to requests for comment on the decision.

New York-based Pfizer, which acquired Wyeth in 2009, sued AstraZeneca in 2021. It said that AstraZeneca's Tagrisso infringed patents related to the breast-cancer drug Nerlynx, which Puma Biotechnology PBYI.O makes with a license to Pfizer's patents.

Tagrisso earned UK-based AstraZeneca more than $7.2 billion in global revenue last year, according to a company report.

Wyeth won a $107.5 million jury verdict against AstraZeneca in Delaware in 2024. U.S. District Judge Matthew Kennelly, sitting by designation in Delaware, overturned the verdict later that year after finding that the patents lacked valid written descriptions of their inventions and would not enable an ordinary scientist in the field to recreate them without undue experimentation.

The Federal Circuit affirmed Kennelly's decision on Thursday on the same grounds.

The case is Wyeth LLC v. AstraZeneca Pharmaceuticals LP, U.S. Court of Appeals for the Federal Circuit, No. 24-2325.

For Wyeth: Jennifer Swize of Jones Day

For AstraZeneca: Christopher Sipes of Covington & Burling

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