The USPTO issued a two page memorandum to the Patent Examining Corps noting that some of the USPTO’s written description guidance pertaining to antibody claims is “outdated.” The memo specifically notes withdrawal of the “newly characterized antigen test” for written description of antibodies, and advises that additional written description examination guidance is forthcoming.

The Memo On Written Description Guidance

The memorandum was issued by Deputy Commissioner for Patent Examination Policy, Robert W. Bahr, and discusses three aspects of USPTO written description guidance.

Amgen and the Newly Characterized Antigen Test

First, the memorandum addresses the recent Federal Circuit decision in Amgen Inc. v. Sanofi, 872 F.3d 1367 (Fed. Cir. 2017), which criticized the “newly characterized antigen test.” The test had been embodied in jury instructions stating that “the disclosure of a newly characterized antigen by its structure, formula, chemical name, or physical properties” may satisfy written description of a claimed antibody. The Federal Circuit found the instructions to be inconsistent with its decision in Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010), and “the statutory ‘quid pro quo’ of the patent system where one describes an invention, and if the law’s other requirements are met, one obtains a patent.” The Federal Circuit explained in Amgen that when an antibody is claimed, 35 U.S.C. § 112(a) requires adequate written description of the antibody itself.

The memorandum advises that the “newly characterized antigen” test should not be used in determining whether there is adequate written description for a claim drawn to an antibody.

Outdated Written Description Guidance 

The memorandum also notes that portions of the USPTO’s 2008 Written Description Training Materials are outdated. In particular, the memorandum states that several examples require further analysis for subject matter eligibility under 35 U.S.C. 101. Thus, the USPTO will prepare new guidance “to reflect changes in the law since 2008.”

Useful Written Description Guidance 

The memorandum closes by highlighting existing guidance that remains useful:

  • MPEP 2161.01 and 2163 except for the newly characterized antigen test in MPEP 2163
  • The 2015 training module entitled “Examining Claims for Compliance with 35 USC 112(a): Overview & Part I – Written Description”
  • The 2015 Written Description Workshop materials
  • The 2015-16 training slide set entitled “Antibody Decisions and Their Compliance with the Written Description Requirement,” except for slide 17, bullet 2, which references the 2008 USPTO Written Description Training Materials

These materials are available on the Examination Guidance and Training Materials page of the USPTO website.