RE:RE:RE:RE:RE:On GLP-1 agonists US Senate passes anti-patent thicket billFebruary 23, 2024, - The latest chapter in the complex and multifaceted Daiichi Sankyo Inc. v. Seagen Inc.[Pfizer] patent dispute — concerning antibody-drug conjugate technology, or ADC, and pitting Seagen against Daiichi and its collaborator, AstraZeneca — concluded recently.
On Jan. 16, the Patent Trial and Appeal Board issued a final written decision in a post grant review proceeding, finding all challenged claims of Seagen's U.S. Patent No. 10,808,039 invalid.
The claims relate to an ADC genus incorporating a linker containing a tetrapeptide of nonmethylated amino acids in which each of the four amino acids is glycine, or Gly, or phenylalanine, or Phe, as well as certain additional elements, any drug moiety and any antibody where the drug moiety is cleaved from the antibody intracellularly in a patient.
The board found the claims unpatentable for three reasons — lack of enablement, lack of written description and anticipation on the basis that the patent was not entitled to its claimed priority date because the priority application provided inadequate written description — and rejected an indefiniteness argument.
This comes after a jury in the U.S. District Court for the Eastern District of Texas reached the contrary result and rejected Daiichi and AstraZeneca's enablement and written description arguments in April 2022 and found infringement by Daiichi and AstraZeneca's Enhertu trastuzumab-deruxtecan ADC product in Seagen Inc. v. Daiichi Sankyo Co.[2] Seagen was awarded $41.82 million in damages and an 8% running royalty. Pfizer has since allowed its appeal to expire.