Board IPR obviousness FWD reversed as “pure conjecture coupled with hindsight reliance”

University of Strathclyde v. Clear-Vu Lighting LLC

Docket No. 2020-2243 (IPR2019-00431) (


November 4, 2021

Brief Summary:  Board IPR obviousness FWD reversed as “pure conjecture coupled with hindsight reliance”.

Summary:  University of Strathclyde (US) appealed Board final written decision (FWD) finding claims 1-4 of US 9,839,706 relating to methods for disinfecting air from Gram-positive bacteria (e.g., MRSA) using visible light without a photosensitizer unpatentable as obvious.  The Board determined that ‘706 claims 1 and 3 would have been obvious over two non-patent prior art references (Ashkenazi in view of Nitzan) and claims 2 and 4 in view of Ashkenazi, Nitzan and a published US patent application (Jones).  This appeal is focused on the rejection of claims 1 and 3 over Ashkenazi and Nitzan.  The FC panel opinion explains that Ashkenazi describes the use of the photosensitizers gamma-aminolevulinic acid (ALA) or the vitamin riboflavin (without ALA) for photoeradication of the Gram-positive bacteria P. acnes (which causes acne), which were each found to increase the amount of intracellular porphyrin (e.g., “the greater the intracellular amount of the porphyrin the better are the eradication results.”)  Nitzan’ studies “focused on how exogenous porphyrins—i.e., a culture media supplemented with porphyrins—would affect inactivation” of Gram-positive MRSA and reported “no decrease in viability . . . after illumination”.  The Board found that “ ‘Ashkenazi and Nitzan teach or suggest all the limitations of claims 1 and 3,’ and that a person of ordinary skill in the art would have been motivated to combine these two references and ‘would have had a reasonable expectation of successfully doing so’”, relying “largely on Ashkenazi’s teachings that increasing the light doses, the number of illuminations, and the length of time the bacteria are cultured resulted in greater inactivation for both the ALA and non-ALA P. acnes to support its finding that a skilled artisan applying Ashkenazi’s teachings would expect at least ‘some’ inactivation for nonALA MRSA.”  The FC panel “review[ed] the Board’s legal conclusions de novo and its factual findings for substantial evidence” (Pers. Web, FC 2017; OSI, FC 2019) and explained that “[a]n obviousness determination generally requires a finding that ‘all claimed limitations are disclosed in the prior art’” (PAR, FC 2014; Koninklijke, FC 2020 (“common knowledge of a skilled artisan can be used to supply a missing limitation in some circumstances”)) and “that a person of ordinary skill in the art would have been motivated to combine or modify the teachings in the prior art and would have had a reasonable expectation of success in doing so” (OSI (hindsight)).  The FC panel found the Board erroneously found “that the prior art disclosed all claim limitations” (i.e., “inactivating one of the claimed Gram-positive bacteria without using a photosensitizer”) since Ashkenazi did not treat without a photosensitizer (ALA or riboflavin) and “there is no evidence that Nitzan successfully achieved inactivation” without a photosensitizer (“Given neither Ashkenazi nor Nitzan teaches or suggests inactivation of any bacteria without using a photosensitizer, we fail to see why a skilled artisan would opt to entirely omit a photosensitizer when combining these references.”; ATD FC 1998) (“hindsight combination of components selectively culled from the prior art to fit the parameters of the patented invention”); only support for reasonable expectation of success being “pure conjecture coupled with hindsight reliance on the teachings in the ’706 patent”; no reason given for discrediting expert testimony; “[t]he inventor’s own path itself never leads to a conclusion of obviousness; that is hindsight. What matters is the path that the person of ordinary skill in the art would have followed, as evidenced by the pertinent prior art.” Otsuka Pharm. Co., v. Sandoz, Inc., 678 F.3d 1280, 1296 (Fed. Cir. 2012)).  The Board IPR decision was therefore reversed.

This entry was posted in Inter Parties Review (IPR), IPR, Obviousness. Bookmark the permalink.

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