Lets’ B. Cereus, No Reasonable Fact Finder Could Find an Expectation of Success Based on the Teachings of a Prior Art Reference That Failed to Achieve That Which The Inventor Succeeds
| December 6, 2021
University of Strathclyde vs., Clear-Vu Lighting LLC
Circuit Judges Reyna, Clevenger and Stoll (author).
Summary:
Here, the University of Strathclyde (Strathclyde herein after) appeals from a final written decision of the Patent Trail and Appeal Board holding claims 1 to 4 of U.S. Patent No. 9,839,706 unpatentable as obvious.
The patent relates to effective sterilization methods for environmental decontamination of air and surfaces of, amongst other antibiotic resistant Gram-positive bacteria, Methicillin-resistant Staphylococcus aureus (MRSA). Specifically, sterilization is performed via photoinactivation without the need for a photosensitizing agent.
Claim 1[1] is as follows:
1. A method for disinfecting air, contact surfaces or materials by inactivating one or more pathogenic Gram-positive bacteria in the air, on the contact surfaces or on the materials, said method comprising exposing the one or more pathogenic Gram-positive bacteria to visible light without using a photosensitizer, wherein the one or more pathogenic Gram-positive bacteria are selected from the group consisting of Methicillin-resistant Staphylococcus aureus (MRSA), Coagulase-Negative Staphylococcus (CONS), Streptococcus, Enterococcus, and Clostridium species, and wherein a portion of the visible light that inactivates the one or more pathogenic Gram-positive bacteria consists of wavelengths in the range 400-420 nm, and wherein the method is performed outside of the human body and the contact surfaces or the materials are non-living.
The Board determined that claim 1 above would have been obvious over Ashkenazi in view of Nitzan. Ashkenazi is an article that discusses photoeradication of a Gram-positive bacterium, stating that “In the case of P. acnes (leading cause of acne) or other bacterial cells that produce porphyrins…. Blue light may photoinactivate the intact bacterial cells.” However, as noted by the CAFC, the methods of Ashkenazi always contained a photosensitive agent. Ashkenazi taught that increasing the light doses, the number of illuminations, and the length of time the bacteria are cultured resulted in greater inactivation.
The Nitzan article studied the effects of ALA (photosensitive agent) on Gram-positive bacteria, including MRSA. In Nitzan, for all the non-ALA MRSA cultures, it was reported therein that a 1.0 survival fraction was observed, meaning there was “no decrease in viability…after illumination” with blue light.
The Board ultimately held that Ashkenazi and Nitzan taught or suggested all the limitations of claim 1, 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.”
Although neither of the references achieved inactivation of any bacteria without using a photosensitizer, the Board nonetheless found that a skilled artisan would have reasonably expected “some” amount of inactivation because the claims “do not require any specific amount of inactivation.”
Ultimately, the CAFC disagreed with the Boards’ findings.
Initially, the CAFC emphasized that “[T]he substantial evidence standard asks ‘whether a reasonable fact finder could have arrived at the agency’s decision,’ and ‘involves examination of the record as a whole, taking into account evidence that both justifies and detracts from an agency’s decision.’” OSI Pharms., LLC v. Apotex Inc., 939 F.3d 1375, 1381–82 (Fed. Cir. 2019) (quoting In re Gartside, 203 F.3d 1305, 1312 (Fed. Cir. 2000)).
That, “An obviousness determination generally requires a finding that “all claimed limitations are disclosed in the prior art,” PAR Pharm., Inc. v. TWI Pharms., Inc., 773 F.3d 1186, 1194 (Fed. Cir. 2014); cf. Koninklijke Philips N.V. v. Google LLC, 948 F.3d 1330, 1337–38 (Fed. Cir. 2020).
“Whether the prior art discloses a claim limitation, whether a skilled artisan would have been motivated to modify or combine teachings in the prior art, and whether she would have had a reasonable expectation of success in doing so are questions of fact. Tech. Consumer Prods., Inc. v. Lighting Sci. Grp. Corp., 955 F.3d 16, 22 (Fed. Cir. 2020); OSI Pharm., 939 F.3d at 1382.
Here, “the only dispute is whether these references teach inactivating one of the claimed Gram-positive bacteria without using a photosensitizer.” The CAFC stated that the “Board’s finding that this was taught by the combination of Ashkenazi and Nitzan is not supported by substantial evidence.”
Claim 1 requires both (i) exposing the bacterial to 400 to 420 nm blue light without using a photosensitizers and (ii) that the bacteria are inactivated as a result. Here, Ashkenazi achieves inactivation after exposure to 407 to 420 nm blue light but with a photosensitizer. On the other hand, Nitzan provides an example in which MRSA is exposed to 407 to 420 nm blue light without a photosensitizer, but there is no evidence that Nitzan successfully achieved inactivation under the conditions.
The Board agreed with Clear-Vu’s argument that a skilled artisan would have prepared a MRSA culture according to the method described in Nitzan and applied Ashkenazi’s teaching that increasing the light energy, number of illuminations, and length of time the bacteria are cultured, and so arrived at the Patented claims.
However, the CAFC held that “given neither Ashkenazi nor Nitzan teaches or suggests inactivation of any bacteria without using a photosensitizer” they failed “to see why a skilled artisan would opt to entirely omit a photosensitizer when combining these references.” The CAFC stressed that Nitzan itself disclosed that a photosensitizer-free embodiment was “wholly unsuccessful in achieving inactivation.”
Again, the CAFC emphasized that claim 1 requires both (i) exposing the bacterial to 400 to 420 nm blue light without using a photosensitizers and (ii) that the bacteria are inactivated as a result, and declined Clear-Vu’s invitation to read the inactivation limitation in isolation divorced from the claim as a whole concluding that “Obviousness cannot be based on the hindsight combination of components selectively culled from the prior art to fit the parameters of the patented invention.”
Next, the CAFC analyzed the Board’s finding on reasonable expectation of success and again, declined to agree.
The Board had relied upon (i) both parties agreeing that MRSA naturally produces at least some amount of endogenous porphyrins and (ii) Ashkenazi’s teaching that “blue light may” inactivate “other bacterial cells that produce porphyrins.
Here, the CAFC focused on Nitzan, as evidence on record showing the opposite. The CAFC reaffirmed that “absolute predictability of success is not required, only a reasonable expectation.” In this case, where the prior art reference fails to “achieve that at which the inventors succeeded, no reasonable fact finder could find an expectation of success based on the teachings of that same prior art.”
Thus, the CAFC concluded that the Board’s finding was not supported by substantial evidence, and so reversed its obviousness determination.
Take-away:
- The substantial evidence standard asks ‘whether a reasonable fact finder could have arrived at the agency’s decision,’ and ‘involves examination of the record as a whole, taking into account evidence that both justifies and detracts from an agency’s decision.
- If a prior art reference fails to achieve that which the inventor succeeds, it can be argued that no reasonable fact finder could find an expectation of success based thereon.
[1] Claim 2 depends on claim 1. Claim 3 is independent, but contains the same contested features highlighted above in claim 1. Claim 4 is dependent on claim 3.
