Daiichi wins appeal of $42 million US verdict in Enhertu patent case (updated)
02/12/2025 17:08
Adds comment from Pfizer in paragraph 3 By Blake Brittain WASHINGTON, Dec 2 (Reuters) - A U.S. appeals court on Tuesday overturned a nearly $42 million jury verdict won by Pfizer's PFE.N Seagen against Japanese rival drugmaker Daiichi Sankyo 4568.T over allegations that Daiichi and AstraZeneca's AZN.L blockbuster cancer drug Enhertu violated Seagen's patent rights. The U.S. Court of Appeals for the Federal Circuit said that Seagen's patent at issue was invalid, negating the 2022 infringement verdict in Texas. A Pfizer spokesperson said the company is disappointed with the decision and considering next steps. Spokespeople for Daiichi and AstraZeneca did not immediately respond to requests for comment on the decision. Combined sales of Enhertu by AstraZeneca and Daiichi reached $3.75 billion last year. The drug is used to treat several forms of cancer. Seagen sued Daiichi in the U.S. District Court for the Eastern District of Texas in 2020, arguing Enhertu works in the same way as its patent related to antibody-drug conjugates, which use antibodies to target cancer cells with chemotherapy drugs. AstraZeneca later intervened in the case. A jury determined in 2022 that Daiichi owed $41.8 million for infringing the patent. The jury did not find AstraZeneca liable for the infringement. The Federal Circuit overturned the verdict on Tuesday, finding that Seagen's patent was invalid because it did not adequately describe the antibody invention it covered. Pfizer acquired Washington State-based Seagen for $43 billion in 2023. The case is Seagen Inc v. Daiichi Sankyo Co, U.S. Court of Appeals for the Federal Circuit, No. 23-2424 For Seagen: Sara Horton of Willkie Farr & Gallagher For Daiichi: Christopher Sipes of Covington & Burling Read more: Seagen wins $42 mln patent verdict in Daiichi cancer drug case (Reporting by Blake Brittain in Washington)