Writing Strong Antibody Claims: Avoiding or Addressing USPTO Rejections for Written Description and Enablement

Written Description and Enablement Generally

The legal standards for written description and enablement are well-established. To meet the written description requirement, the specification must convey with reasonable clarity that as of the filing date the inventor was in possession of the claimed invention. See, Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 1560 (Fed. Cir. 1991); Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc) (specification must “clearly allow persons of ordinary skill in the art to recognize that [the inventor] invented what is claimed.”). The enablement requirement is met if the specification would allow a person of ordinary skill in the art to make and use the claimed invention without undue experimentation. See, Amgen, Inc. v. Sanofi, 598 U.S. 594, 611 (2023).
The Supreme Court observed in Amgen that “[d]espite recent advances, aspects of antibody science remain unpredictable … [and] scientists understand that changing even one amino acid in the sequence can alter an antibody’s structure and function” in unpredictable ways. Amgen, 598 U.S. at 612-13. In Ariad, the Federal Circuit found that the disclosure of three types of molecules supporting the claimed substance for interfering with a gene transcription factor was insufficient to meet the written description requirement. Ariad, 598 F.3d at 1355-58. In Amgen, the Supreme Court held that a claim to antibodies for treating high cholesterol was not adequately enabled even though the specification disclosed multiple embodiments including 26 different antibodies identified by their amino acid sequences. Amgen, 598 U.S. at 612.
Below are best practices for drafting antibody claims and specifications.