Seagen wins $42 mln patent verdict in Daiichi cancer drug case

A sign of Japanese pharmaceutical company Daiichi Sankyo Co., Ltd. is seen at the company’s head office in Tokyo July 17, 2009. REUTERS/Stringer (JAPAN BUSINESS HEALTH)

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  • Jury found Enhertu drug violated Seagen breast cancer treatment patent
  • Daiichi said it plans to appeal, patent is under review

(Reuters) – A jury in Marshall, Texas, on Friday awarded biotech company Seagen Inc nearly $42 million from Japanese rival drugmaker Daiichi Sankyo Co over claims that Daiichi and AstraZeneca plc’s breast-cancer drug Enhertu violates Seagen’s patent rights.

The jury found that Daiichi willfully infringed a patent owned by Washington State-based Seagen that covers technology for delivering chemotherapy drugs to cancer cells.

Daiichi said in a statement that it disagreed with the verdict and was exploring its options, including potential post-trial motions and an appeal. It also said the U.S. Patent and Trademark Office granted its request to review the patent’s validity on Thursday.

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Seagen said it was pleased with the verdict and would request additional royalties on future sales of Enhertu in the United States until the patent expires in 2024.

Cambridge, U.K.-based AstraZeneca, which co-developed Enhertu and markets it in the United States with Daiichi, did not immediately respond to a request for comment. The jury did not find it responsible for any of the $41.8 million award.

Enhertu is considered a potential multi-billion dollar drug to treat metastatic breast cancer. AstraZeneca reported that sales of Enhertu outside of Japan were worth $426 million last year.

Seagen filed the lawsuit in the U.S. District Court for the Eastern District of Texas in 2020, claiming Enhertu works in the same way as its patent related to antibody-drug conjugates, which use antibodies to target cancer cells with chemotherapy drugs.

U.S. District Judge Rodney Gilstrap presided over the trial, which began Monday.

The case is Seagen Inc v. Daiichi Sankyo Co, U.S. District Court for the Eastern District of Texas, No. 2:20-cv-00337.

For Seagen: Michael Jacobs of Morrison & Foerster

For AstraZeneca: David Berl of Williams & Connolly

For Daiichi Sankyo: Preston Ratliff of Paul Hastings

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Blake Brittain

Washington-based correspondent covering court cases, trends, and other developments in intellectual property law, including patents, trademarks, copyrights, and trade secrets. Previous experience at Bloomberg Law, Thomson Reuters Practical Law and work as an attorney.

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Lyndia Menjivar