PTAB Adopts Idendex In Finding Markush Group Not Enabled

• Published date: 07 September 2021
• Subject Matter: Intellectual Property, Patent
• Law Firm: Oblon, McClelland, Maier & Neustadt, L.L.P
• Author: Mr Richard D. Kelly

In Post Grant Reviews (PGR) the Patent Trial and Appeal Board (PTAB) may consider all statutory challenges to patent claims including those under 35 U.S.C. ' 112. One such challenge was brought in Syngenta Crop Protection v. FMC Corp in PGR2020-00028 (Syngenta), decided August 31, 2021, against U.S.P. 10,294,202 ('202 patent). The PTAB found all challenged claims, 1-3, 9-13, and 21-30, unpatentable as lacking an enabling disclosure commensurate in scope with the claims and a subset, claims 9 - 13, as lacking written description, 35 U.S.C. ' 112(a).

The '202 patent is directed to pyrrolidinone herbicides:

1. A compound selected from Formula I, N-oxides and salts thereof :

Followed by Markush definitions of each variable covering almost 4 pages of the opinion. The Petitioner asserted, the PTAB agreed, and patentee did not deny that the claims cover over a billion compounds. The PTAB found on a largely undisputed record that the level of skill in the art was relatively high but the art unpredictable. The PTAB also found that Q¹, Q², R¹, and R⁶ groups alone each recite well over a thousand possible independent options. The issue was then the degree of guidance provided in the specification for practicing the full scope of the claims.

The PTAB noted that the specification provides no disclosure of the compounds' mode of action. The PTAB acknowledged that the patentee need disclose an invention's mode of action citing Alcon Research Ltd. v. Barr Labs., Inc., 745 F.3d 1180, 1190 (Fed. Cir. 2014). The Patent Owner admitted that without this information to practice the full scope of the claims, ordinarily skilled artisans must engage in iterative QSAR modeling to develop a structure-activity relationship themselves. The evidence was that knowledge of the mode of action would have assisted in the QSAR modeling process. The Patent Owner's expert testimony to the contrary was rejected on this point because almost half of its expert's 150-plus publications provided a mode of action and only a few provided QSARs for herbicides.

The '202 patent specification had over 350 examples of synthesizing compounds and herbicidal activity for 335 of the compounds. The PTAB noted that the Patent Owner correctly argued there was no requirement either (1) the Specification to disclose testing of "each" claimed compound and modifying of "each" claimed variable, or (2) that an ordinarily skilled artisan know in advance precisely all the compounds that will show herbicidal...