Daiichi Faces Patent Suit Over New Breast Cancer Drug

Law360 (October 20, 2020, 7:16 PM EDT) -- Daiichi Sankyo is facing claims in Texas federal court that its recently approved breast cancer treatment drug, which has allegedly earned the Japanese pharmaceutical giant $70 million in sales, infringes a U.S. biotechnology company's patent.

Seagen Inc. lodged a complaint on Monday claiming that Daiichi Sankyo Co. Ltd.'s breast cancer treatment medication it markets under the brand name Enhertu infringes a patent covering the delivery of a drug that Seagen sells called Adcetris.

Seagen has been marketing Adcetris since 2011, and the U.S. Food and Drug Administration approved Daiichi Sankyo's Enhertu in January, according to the lawsuit.

Seagen, which had been doing...

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