Daiichi Owes Seagen $41.8 Million Over Cancer Treatment Patents

Daiichi Sankyo Co. Ltd. must pay Seagen Inc. $41.8 million because Enhertu, a breast-cancer treatment Daiichi markets with AstraZeneca Pharmaceuticals LP, infringes a Seagen patent for technology that delivers chemotherapy drugs directly to cancer cells, an East Texas jury found.

A jury in the U.S. District Court for the Eastern District of Texas found Daiichi does infringe U.S. Patent No. 10,808,039. Jurors also rejected arguments that the patent is invalid because it doesn’t cover a novel invention.

The trial started Monday in Marshall, Texas.

“Daiichi Sankyo disagrees with the jury verdict, is committed to defending its rights, and will explore options with respect to the jury verdict, including post-trial motions and an appeal,” Naoto Tsukaguchi, Corporate Officer and General Counsel for Daiichi Sankyo, said in a statement.

Seagen said it will ask the court to award a royalty on future sales of Enhertu in the U.S. until patent expiry in November 2024. “The court will determine the amount of these payments in a decision Seagen anticipates later this year,” the company said.

The decision came one day after Daiichi and AstraZeneca won a rare administrative patent tribunal rehearing after the board rejected their original challenge to a patent they were accused of infringing. Seagen said it will “vigorously defend” the patent in those review proceedings.

Washington-based Seagen alleged the medicine Enhertu infringed patented technology that enables the delivery of chemotherapy drugs directly to cancer cells. Seagen said Enhertu sales have totaled over $70 million, and Daiichi appeared “intent upon expanding its infringing activities.”

AstraZeneca, which markets Enhertu in the U.S., intervened in the suit. It must split with Daiichi any losses in the infringement case, according to court filings.

Judge Rodney Gilstrap last month refused to invalidate Seagen’s patent, finding questions about whether it covered an invention that isn’t novel were for jurors to resolve.

Gilstrap in the same order said Daiichi owed Seagen $75,000 as a sanction for “discovery conduct.” Seagen argued in court filings Daiichi repeatedly flouted its obligation to produce certain documents.

Morrison & Foerster LLP, Gillam Smith LLP, and Ward, Smith & Hill PLLC represented Seagen. Paul Hastings LLP, The Dacus Firm P.C., and Mann Tindel Thompson represented Daiichi. Williams & Connolly LLP and Wilson Robertson & Cornelius P.C. represented AstraZeneca.

The case is Seagen Inc. v. Daiichi Sankyo Co., E.D. Tex., No. 20-cv-00337, verdict 4/8/22.

To contact the reporter on this story:
Matthew Bultman in Arlington at mbultman@bloomberg.net

To contact the editor responsible for this story:
Jay-Anne Casuga at jcasuga1@bloomberg.net

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