February 16, 2023by Richard Treanor

In the 1960s the Federal Circuit’s predecessor court, the Court of Customs and Patent Appeals (CCPA), established a “flavor” of anticipation that did not require an example – when a reference was so limited and specific in its disclosure that one of ordinary skill in the art was able to “at once envisage” the specific compound, method, etc., claimed, that claim was anticipated by the reference. On December 20, 2022, the Patent Trial and Appeal Board (PTAB) in Ex parte Mizushima (Appeal 2022-003863) extended this theory of anticipation to a secondary, academic use of an “envisioned” composition.

In Mizushima the claim was directed to a powdered coloring material comprising at least one pigment selected from three protein-based pigment candidates in combination with at least one of three chelating agents. The prior art cited described an academic study of the influence of temperature, pH, and preservatives on one of the claimed pigment candidates, all conducted in solution. Eight preservatives were used, one of which was a claimed chelating agent (citric acid), used in solution in a claimed weight ratio. In addition to the solution studies, the paper provided a microstructure analysis on dried solutions of the pigment with two of the preservatives – sugar, described as being known for stabilizing proteins, and salt.

In affirming the examiner’s rejection, the Board acknowledged that the reference failed to make a solid composition comprising the pigment and citric acid in the claimed amounts, but took the position that one of ordinary skill “would have readily recognized or inferred” such a solid composition as emanating from the described solution using citric acid given the description of dried solutions using sugar and salt.

Ex parte Mizushima thus extends traditional “Petering” anticipation, which typically arises when an examiner chooses a combination of ingredients from a limited list to provide a claimed composition, to include different physical forms of ingredient combinations described in a reference for the purpose of academic study. That is, in a typical “Petering” situation the examiner constructs the anticipatory composition for the same reason the inventors did – to cure a disease, to treat a surface, to add to gasoline, etc. Here, the only reason the authors dried two of their solutions was academic curiosity – to see how two of their preservatives coated the pigment. Would the Federal Circuit agree with the Board that academic curiosity is sufficient motivation for one of ordinary skill to “at once envisage” a new form of a described material?

Judges: Hastings, Colaianni, Kennedy


October 17, 2022by Jacob Doughty

Mylan Pharm. v. Merck Sharp & Dohme Corp., No. 2021-2121 (Fed. Cir. Sep. 29, 2022), is a recent decision of the Federal Circuit considering, inter alia, whether a prior art disclosure of a genus of salts was sufficient to anticipate or render obvious a single salt species.

In an Inter Partes Review proceeding before the PTAB, Mylan asserted that claims of a Merck patent were anticipated by or obvious over a prior Merck patent publication, Edmondson. The PTAB concluded that Mylan failed to prove unpatentability, and Mylan appealed. The claims of the Merck patent at issue were directed to sitagliptin dihydrogenphosphate (DHP). Exemplary claims include claims 1, 2, and 4:

1. A dihydrogenphosphate salt of a 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro [1,2,4]tria-zolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-tri-fluorophenyl)butan-2-amine… or a hydrate thereof.

2. The salt of claim 1 of structural formula II having the (R)-configuration at the chiral center marked with an *


4. The salt of claim 2 characterized in being a crystalline monohydrate.

Edmondson disclosed sitagliptin in a list of 33 compounds. Edmondson further disclosed acids forming pharmaceutically acceptable salts including phosphoric acid in a list of eight preferred acids. Mylan argued that this was sufficient to anticipate claim 1, relying on the reasoning of In re Petering, 301 F.2d 676, 681 (C.C.P.A. 1962) (prior art may be deemed to disclose each member of prior art genus when skilled artisan can “at once envisage each member of this limited class”).

Merck countered that the combined list of 33 compounds and eight preferred salts, taking into account various stoichiometric possibilities, encompassed  957 salts, which was not sufficient for a skilled artisan to “at once envisage” the salt of claim 1.

The Federal Circuit agreed with Merck that Edmondson did not “expressly disclose a 1:1 sitagliptin DHP salt.” The Federal Circuit credited expert testimony (including testimony of Mylan’s own expert) that Edmondson did not direct a skilled artisan to sitagliptin among the list of 33 compounds and did not single out phosphoric acid or any phosphate salt among the enumerated salts. The Federal Circuit noted particularly that the 957 salts of Edmondson was “a far cry from the 20 compounds ‘envisaged’ by the narrow genus in Petering.”

As to obviousness, interestingly, Merck was able to eliminate Edmondson as a reference as to claims 1 and 2 by proving prior invention and relying on the obviousness exception for commonly owned prior art of pre-AIA 35 USC 103(c). However, this approach was not effective as to claim 4, which was limited to a crystalline monohydrate of the (R)-configuration of 1:1 sitagliptin DHP.

As to claim 4, Mylan relied on Edmondson’s indication that the described salts may exist in more than one crystal structure and in the form of hydrates. Mylan further relied on the disclosure in a secondary reference of the pharmaceutical importance and prevalence of crystalline hydrates of pharmaceutical compounds.

The CAFC agreed with the PTAB and Merck that the general teachings of the secondary reference would not have led a skilled artisan to prepare a crystalline monohydrate of the (R)-configuration of 1:1 sitagliptin DHP based on the teachings of Edmondson with a reasonable expectation of success, noting the unpredictability of hydrate formation and function for specific compounds.

The Federal Circuit briefly noted the PTAB’s consideration of Merck’s evidence of unexpected results, but also noted that “there is no need to reach objective indicia of nonobviousness where the petitioner has not made a showing necessary to prevail on threshold obviousness issues.”

Takeaway: During examination, claims directed to chemical compounds and compositions are often rejected over prior art disclosing generic chemical formulae or separate lists of components. The numbers of specific compounds or compositions encompassed by such prior art can be astronomical. The Mylan case provides some tips for arguing over such rejections (preferably without the need to rely on additional experimental results). Possible arguments include identifying the large number of species encompassed by a prior art genus, emphasizing the lack of direction in the prior art toward the specific selections necessary to obtain a claimed compound or composition, and pointing out the difficulty of applying general teachings regarding selection (e.g., of substituents, subcomponents, etc.) to specific compounds or compositions.

Judges: Lourie, Reyna, Stoll



April 7, 2022by Matthew Barnet

U.S. patent claims typically use the terms “comprising” and “consisting of” when reciting components of a composition. “Comprising” indicates that the composition must include the recited components, but also can include unrecited components, while “consisting of” indicates that the composition excludes unrecited components.

The term “comprising” advantageously provides the applicant with broader scope of protection than “consisting of.” However, such breadth sometimes opens claims to additional prior art. In such cases, “consisting of” can be helpful to distinguish the claims from the prior art.

When claims use both “comprising” and “consisting of,” the scope of the claims must be analyzed carefully. This issue is illustrated in the recent case of Ex parte Rankin (Appeal No. 2021-001726).

Independent claim 40 recited (in part) a composition comprising:

(i) a gel base consisting of:

a wax or oil and;

a salt; and

(ii) titanium dioxide, zinc oxide, barium sulfate, or a combination thereof dispersed in the gel base.

The examiner rejected claim 40 as anticipated by two different references disclosing gels containing titanium dioxide. The gels also included polymeric gelling agents. In each case, the examiner took the position that the gelling agent was within the scope of the claim based on the open “comprising” term in the preamble. For example, in one anticipation rejection, the examiner stated that claim 40 “is interpreted to mean that the gel base consists of a wax or oil, and a salt, but it does not exclude addition of other components, such as the block polymers taught by [the cited reference] to make the final…product.”

In contrast, the applicant argued that the closed “consisting of” term excluded the polymeric gelling agents of the prior art. For example, the applicant alleged that the gels of the cited reference “differ structurally from the gel of claims 40-55 due to the latter being composed exclusively of a wax or oil and salt and therefore excluding the polymers…as constituent structural components.”

The PTAB agreed with the applicant. The PTAB acknowledged that “the ‘comprising’ language in the claim allows the mixture of the gel base and titanium dioxide, zinc oxide, barium sulfate or combination to include additional components dispersed in the gel base.” However, due to the “consisting of” language, “the gel base may contain only the recited wax or oil and salt…[W]e do not agree [with the examiner] that the claim language allows for the addition of ingredients to the gel base.” Accordingly, the PTAB reversed the anticipation rejections.

Takeaway: Whenever a claim uses both “comprising” and “consisting of,” the scope of the claim must be analyzed carefully. The closed, “consisting of” term might be intended to exclude a component disclosed in the prior art, but the examiner might take the position that the component is within the claim scope due to the “comprising” term. In such cases, it is important to clearly identify how the components of the prior art correspond to the claim. In Rankin, the applicant successfully argued that the polymeric gelling agent of the prior art was a component of the gel base (thus excluded by the “consisting of” term) rather than a component dispersed in the gel base (which would have been included by the “comprising” term).

Judges: Adams, Grimes, Jenks


December 22, 2021by Matthew Barnet

In Ex parte Ruvolo (Appeal No. 2021-001708), the examiner rejected nucleotide claims as anticipated under § 102. The PTAB reversed.

Independent claim 12 recited (in part):

A composition of matter comprising:

a first population of oligonucleotides comprising a top strand sequence having the following formula:

V1-B-3’; and

a second population of oligonucleotides comprising a bottom strand sequence having the following formula:


Claim 12 further specified (in part) that (i) the nucleotide sequences of B and B’ are complementary and at least 15 nucleotides in length, (ii) the first and second population of oligonucleotides are capable of hybridizing to each other to produce a population of duplexes, and (iii) V1 and V2’ hybridize to different sites in a reference genome.

The examiner cited as anticipatory a reference (Koroulis) disclosing an oligonucleotide array. The reference included the general statement that the array could “contain all possible oligonucleotides of a given length n.” The examiner took the position that “[g]iven that the composition/array of Koroulis et al., encompasses all possible oligonucleotides of a length n, such must encompass the very oligonucleotides present in the claimed composition and kit, including that represented by the formulae of V1-B-3’; and V2‘-B’-3’.”

The appellant argued that the general statement in Koroulis was insufficient for anticipation, and that “[t]he Office Action makes no attempt to identify where Koroulis discloses the particular claim elements recited by the rejected claims.”

The PTAB sided with the appellant. It found that “[t]he bare statement that an array can include all possible nucleotides having an undefined length is not a disclosure of the two populations of oligonucleotides – having segments meeting specified structural requirements, arranged in a specified way – that are recited in Appellant’s claims.” Accordingly, the PTAB reversed the anticipation rejection.

The examiner also rejected the claims as patent ineligible under § 101, as allegedly directed to a natural phenomenon (“the claims are to oligonucleotides, the nucleotide sequence of which can occur in nature”). The PTAB also reversed this rejection, as a straightforward application of the U.S. Supreme Court’s Myriad decision.

In particular, the PTAB found the claimed oligonucleotides to be analogous to the cDNA found patent eligible in Myriad: “[t]he V1 and V2’ segments recited in Appellants’ claims might have the same sequence of nucleotides as found in a naturally occurring genome (since they hybridize to a reference genome) but the Examiner has not shown that a population of such segments – having variable sequences – are naturally found next to a common B or B’ sequence in their natural state.” Accordingly, the PTAB reversed the eligibility rejection.

Takeaway: Anticipation requires that a reference discloses “all of the limitations arranged or combined in the same way as recited in the claim.” Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1371 (Fed. Cir. 2008). Ex parte Ruvolo shows that an overly general disclosure is insufficient to establish anticipation if the disclosure does not address specific limitations in the claims. By emphasizing the specific limitations in the claims, the Appellant in Ex parte Ruvolo overcame the anticipation rejection, as well as the § 101 rejection.

Judges: Grimes, Hulse, Townsend


November 29, 2021by Beau Burton

In Ex parte Talamoni (Appeal No. 2020-006553), the Patent Trial and Appeal Board (“Board”) rejected an Examiner’s claim construction overriding the phrase “derived from the reaction product of” with “comprising.”

The independent claim on appeal read:

A composition comprising an acrylic adhesive derived from the reaction product of

(a) an acrylic ester of monohydric alcohol having an alkyl group of the 5 to 10 carbon atoms; and

(b) a nonpolar acrylic monomer having a solubility of less than 9.2 as measured by the Fedors method using a homopolymer of the nonpolar acrylic monomer,

wherein the reaction product has a side chain crystallinity.

The Examiner rejected the claim as anticipated by or, in the alternative, obvious in view of a reference that disclosed a terpolymer produced from monomers (a) and (b) and 0.5–5 wt% of a monomer (c) (a monoolefinically unsaturated ketone). The Examiner argued the “side chain crystallinity” although not disclosed would be present in view of In re Spada (i.e., “[w]hen the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not”). The Board disagreed.

At the outset, the Board found that the phrase “derived from the reaction product of” monomers (a) and (b) would be understood by those of skill in the art to exclude the terpolymer of the prior art derived from monomers (a), (b), and (c). The Board did agree that the use of “comprising” in the preamble opened the claim up to additional unrecited ingredients such as tackifiers but it did not override or expand the requirement for a reaction product obtained from the two monomers (a) and (b). Accordingly, the Board reversed the anticipation rejection.

As for obviousness, the Board found that the prior art taught away from omitting monomer (c) since it taught the monomer (c) provided the terpolymer with stability and stated, “if the amount of monomer (c) is less than 0.5 mass %, an insufficient effect is produced by the addition.” With no reason for why a person of ordinary skill in the art would have been motivated to omit monomer (c) from the prior art, the Board reversed the obviousness rejection.

Finally, the Board emphasized that the Examiner was not entitled to rely on the presumption from Spada because Appellant’s claim did not cover a reaction mixture containing monomer (c) and the breadth of monomer (c) in terms of the amount and potential species was too broad to conclude that the prior art’s terpolymer was substantially identical to the claimed copolymer of monomers (a) and (b).

Takeaway: In re Talamoni is notable for two reasons. First, the Board found the phrase “derived from the reaction product of … (a) … and (b)” to be closed. While savvy US applicants are accustomed to “comprising” and “consisting of,” phrases like this tend to be more common in applications originating outside the US. Accordingly, it is a good practice to replace uncommon transitional phrases with the corresponding US equivalent (e.g., comprising, consisting essentially of, or consisting of) to limit these types of disputes. And second, the Board correctly found that use of the transitional phrase “comprising” in the preamble did not render the following transitional phrase obsolete. Unfortunately, this type of interpretation before an Examiner is not uncommon, but it is promising to see the Board consistently reaching the correct conclusion. See, e.g., https://www.elementiplaw.com/comprising-is-not-a-weasel-word/ (PTAB rejecting an Examiner’s attempt to construe “comprising … a single odorant chamber” to allow for a plurality of chambers).

Judges: G. Best, N. Wilson, M. Cashion, Jr.


April 23, 2021by Matthew Barnet

In an anticipation rejection, every element and limitation of the claimed invention must be found in a single prior art reference, arranged as in the claim. However, “it is not enough that the prior art reference . . . includes multiple, distinct teachings that [an ordinary] artisan might somehow combine to achieve the claimed invention.” Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1371 (Fed. Cir. 2008). Instead, the reference must “clearly and unequivocally disclose the claimed [invention] or direct those skilled in the art to the [invention] without any need for picking, choosing, and combining various disclosures not directly related to each other by the teachings of the cited reference.” Id. (quoting In re Arkley, 455 F.2d 586, 587 (C.C.P.A. 1972)). Although “[s]uch picking and choosing may be entirely proper in the making of a 103, obviousness rejection . . . it has no place in the making of a 102, anticipation rejection.” Arkley, 455 F.2d at 587-88.

This issue is illustrated in the recent Patent Trial and Appeal Board (“Board”) case of Ex parte Eckhardt.

Independent claim 16 recited a multilayer pressure-sensitive adhesive assembly comprising a propylheptyl acrylate adhesive copolymer layer and a second acrylate pressure-sensitive adhesive foam layer. The propylheptyl acrylate adhesive copolymer layer comprised (a) 50 to 99.5 weight percent of 2-propylheptyl acrylate as a first monomer, (b) 1.0 to 50 weight percent of a second non-polar monomer, (c) 0.1 to 15 weight percent of a third polar acrylate monomer, and (d) a tackifying resin in an amount of 3 to 100 parts per 100 parts of the copolymer. Independent claims 37 and 38 recited similar multilayer pressure-sensitive assemblies, but with somewhat different components (d), and different scope of components (a), (b) and (c).

The examiner rejected independent claims 16, 37 and 38 as anticipated by a single reference, Bartholomew. In response, the applicant argued that “[t]he cited reference provides a great multiplicity of possible combinations and no direction that would lead one of skill in the art to the claimed invention.” For component (a), the applicant explained that Bartholomew listed “2-propylheptyl acrylate as one of 10 options.” For the specific components (b) and (c) recited in claims 37 and 38, the applicant explained that component (b) was one of eight options listed in Bartholomew, and component (c) was one of ten listed options. For component (d), Bartholomew described a tackifying resin as optional. Based on this, the applicant argued that “the number of possible combinations presented by these passages in Bartholomew is 10 x 8 x 10 x 2 = 1600.” The applicant argued against anticipation because “one of ordinary skill in the art would be required to pick items from at least 1600 types of polymer to arrive at the claimed invention.”

The Board agreed with the applicant, finding that the anticipation rejections “rely upon picking and choosing from various lists in Bartholomew,” and that “[a] preponderance of the evidence supports Appellant’s position that Bartholomew’s disclosure is insufficient to establish anticipation of the compositional components of independent claims 16, 37, and 38.”

Additionally, the Board noted that although the ranges of amounts of components (a), (b) and (c) in Bartholomew overlapped the claimed ranges, “the Examiner has not adequately explained how Bartholomew anticipates the claims” in view of Titanium Metals Corp. v. Banner, 778 F.2d 775 (Fed. Cir. 1985).

Accordingly, the Board reversed the anticipation rejections. However, the Board entered a new ground of rejection, finding the claims obvious over Bartholomew. Specifically, the Board found that the selection of the claimed components, in the claimed amounts, would have been obvious from Bartholomew. The Board was not persuaded by the applicant’s argument of unexpected results, particularly with respect to a showing of criticality and whether the unexpected results were commensurate in scope with the claims.

Takeaway: When an examiner rejects a claim as anticipated based on several selections from lists disclosed in a prior art reference, a strong case can be made against anticipation. After overcoming the anticipation rejection, however, the question of obviousness usually remains. To rebut the case of obviousness, strong evidence of unexpected results often is necessary.

Judges: Gaudette, Hastings, Ren


April 16, 2021by Jacob Doughty1

Ex parte Yim, is a recent decision of the Patent Trial and Appeal Board (PTAB) addressing whether claimed properties were inherent in prior art compositions.

In Ex parte Yim, the claim at issue was directed to a resin. However, the resin was not defined by structure or composition. Instead, only properties of the resin were recited in the claim: (a) content of water-soluble fraction, (b) absorbency against pressure property, and (c) water-soluble fraction shear index property. Independent claim 16 is reproduced in part below:

16. A water-absorbing resin, in which

[a] a content of a water-soluble fraction is 15 wt% or less based on the total weight of the resin,

[b] an absorbency against pressure at 0.3 psi with respect to a saline solution including sodium chloride at 0.9 wt% is 25 g/g or more, and

[c] a water-soluble fraction shear index A/B represented by the following Expression 1 is in a range of 0.1 x 10-5 (s) to 10 x 10-5 (s)….

In rejecting the claim, the examiner relied on a single prior art reference that disclosed a water-absorbing resin but did not disclose the properties recited in the claim. Both the prior art reference and the application on appeal disclosed forming water-absorbing polymers by polymerizing and crosslinking an acrylic acid monomer. The examiner asserted that, in view of the similarities in starting materials and processing steps used in the prior art reference and the application on appeal, the properties in the claim were inherent in the water-soluble resins of the prior art reference.

The examiner further asserted that, even if applicant could demonstrate that none of the water-soluble resins exemplified in the prior art reference had the claimed properties, it would have been obvious to tune the reactions in the prior art references to optimize absorbance/solubility characteristics.

The examiner’s inherency arguments turned, particularly, on the examiner’s determination that the prior art reference used two internal crosslinkers to crosslink an acrylic acid, which was the same or similar to the method disclosed in the application on appeal. Applicant countered by arguing, inter alia, that the steps of the prior art method were different such that the two internal crosslinkers were reacted together before being added to acrylic acid, which could not be said to necessarily result in the claimed properties.

The PTAB found that the examiner had made a good argument that the processes of the prior art reference would result in the claimed properties, such that it became applicant’s burden to show that the exemplified resins did not possess the claimed properties. The PTAB also noted that applicant failed to present arguments rebutting the examiner’s fallback assertion that optimizing the properties of the prior art resin would have been a mere matter of routine experimentation to a skilled artisan. Thus, the examiner’s rejection was affirmed.

Takeaway: Parameter or property claims can be valuable in a patent directed to a material or chemical composition. By keeping strict compositional or structural limitations out of a claim, materials or compositions not contemplated at the time of filing may be encompassed by the claim. Further, if claimed parameters/properties are not explicitly disclosed in the prior art, it can be difficult for a third party to confidently analyze the validity of the claim. However, these advantages in a patent claim can be challenges during examination. While some parameter/property claims “sail through” examination, Ex parte Yim shows that an applicant should be prepared to reproduce prior art examples and provide evidence to rebut assertions of routine optimization to obtain allowance.

Judges: Timm, Smith, Range


February 3, 2021by Jacob Doughty

Ex parte Whalen, is a 2008 decision of the Board of Patent Appeals and Interferences (BPAI) that is listed among the Patent Trial and Appeal Board’s (PTAB) precedential decisions. Ex parte Whalen, is indicated by the PTAB to be precedential as to “Anticipation – 35 U.S.C. § 102… Inherency… evidence and reasoning” and “Obviousness – 35 U.S.C. § 103… Rationales… optimizing a variable.”

According to the PTAB’s Standard Operating Procedure, “[a] precedential decision is binding Board authority in subsequent matter involving similar facts or issues.”

In Ex parte Whalen, the BPAI considered whether an examiner met his burden in asserting inherency, or alternatively routine optimization, of a claimed viscosity that was not explicitly disclosed in the prior art.

Independent claim 1 was identified as a representative claim:

A composition capable of embolizing an aneurysm at a vascular site comprising:

(a) a biocompatible polymer;

(b) a biocompatible contrast agent wherein a sufficient amount of said contrast agent is employed in said composition to effect visualization in vivo; and

(c) a biocompatible solvent which solubilizes said biocompatible polymer

wherein a sufficient amount of said polymer are [sic] employed in said composition such that, upon delivery to a vascular site, a polymer precipitate forms which embolizes said vascular site; and

further wherein the biocompatible polymer has a molecular weight sufficient to impart to the composition a viscosity of at least about 150 cSt at 40° C.

The claim was rejected as anticipated or obvious over several prior art references. All of the cited prior art references disclosed combinations of components (a), (b), and (c) in compositions for embolizing an aneurysm at a vascular site, but none explicitly disclosed a composition having “a molecular weight sufficient to impart to the composition a viscosity of at least about 150 cSt at 40° C.” The examiner argued that the prior art compositions inherently possessed the claimed viscosity or, alternatively, it would have been obvious to a skilled artisan to “optimize” the prior art compositions by increasing their viscosity to the level recited in the claims.

It was undisputed that the prior art disclosed compositions including components (a), (b), and (c) in amounts overlapping those in the specification and claims of the application on appeal. However, the only disclosure in the prior art of viscosity was of a preferred composition having a viscosity much lower than the viscosity specified in claim 1. The BPAI found that the examiner had not met his burden in establishing inherency. The BPAI stated that, even if some of the compositions encompassed by the prior art’s broad disclosure might have the claimed viscosity, “that possibility is not adequate to support a finding of inherent anticipation.” The BPAI noted that the examiner did not provide evidence or scientific reasoning to show that any specific composition disclosed in the prior art was within the scope of claim 1.

The examiner’s obviousness position rested on the assertion that a skilled artisan would have been motivated to optimize the viscosity of the prior art composition to achieve “the safest clinical outcome and avoiding transvenous passage.” The BPAI noted that the prior art disclosed “adjustment of the viscosity of the composition as necessary for catheter delivery can be readily achieved by mere adjustment of the molecular weight of the copolymer composition.” However, the prior art also disclosed that low viscosity was a desired property in embolic compositions and, as noted above, the only disclosed viscosity in the prior art was much lower than that of claim 1.

Taking the foregoing facts into consideration, and mindful of the Supreme Court’s (then) recent command of “flexibility” in the obviousness inquiry (KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007)), the BPAI nonetheless concluded that the examiner had not met his burden. Particularly:

… when the prior art teaches away from the claimed solution as presented here… obviousness cannot be proven merely by showing that a known composition could have been modified by routine experimentation or solely on the expectation of success; it must be shown that those of ordinary skill in the art would have had some apparent reason to modify the known composition in a way that would result in the claimed composition.

That is, the examiner was required but failed to provide an “explanation based on scientific reasoning” that would support the conclusion that a skilled artisan would have considered it obvious to optimize the prior art compositions by increasing their viscosity to the level recited in the claims.

Ex parte Whalen was decided by an expanded five-judge panel, instead of the usual three-judge panel. The Chief Administrative Patent Judge was one of the deciding judges. According to the PTAB’s Standard Operating Procedure, “[a]n expanded panel is not favored and ordinarily will not be used… [a]n expanded panel may be used, where appropriate, to secure and maintain uniformity of the Board’s decisions…”

Takeaway: One of the challenges of prosecuting composition claims (combinations of known components) is the seeming ease with which an examiner can assert that a property not explicitly disclosed in the prior art is inherent and/or would have been readily achieved by a skilled artisan as a matter of routine optimization. Of course, the burden-shifting framework for examination of claims reciting properties is reasonable; however, there remains some burden on the examiner. Rejections based on inherency or routine optimization require that the examiner provide “scientific reasoning” consistent with the overall teaching of the prior art. Conclusory or thinly reasoned assertions of inherency or routine optimization thus provide an avenue for challenge.

Judges: Fleming, Lane, Grimes, Lebovitz, Prats


October 27, 2020by Jacob Doughty

Ex parte Chuang is a 2008 decision of the Board of Patent Appeals and Interferences (BPAI) that is listed among the Patent Trial and Appeal Board’s (PTAB) informative decisions. Ex parte Chuang is indicated by the PTAB to be informative as to “Anticipation – 35 U.S.C. § 102… cDNA.”

According to the PTAB’s Standard Operating Procedure, “[i]nformative decisions set forth Board norms that should be followed in most cases, absent justification, although an informative decision is not binding authority on the Board.”

In Ex parte Chuang, the BPAI considered whether a claim reciting an isolated polypeptide was properly rejected as anticipated by prior art disclosing a cDNA encoding the recited polypeptide.

Independent claim 4 was at issue:

An isolated polypeptide, comprising the amino acid sequence of SEQ ID NO: 1.

In rejecting the claim, the examiner relied on prior art that disclosed isolation of a polynucleotide that encoded a polypeptide having 100% homology to SEQ ID NO: 1. While applicant conceded that, in the prior art, “[o]ne of the myriad cDNAs encodes an amino acid sequence identical to SEQ ID NO: 1,” it was undisputed that the claimed proteins were not physically created in the prior art. Relying on a prior BPAI decision (Lee v. Dryja, 79 U.S.P.Q.2d 1614 (B.P.A.I. 2005)), applicant asserted that disclosure of the cDNA at best rendered its encoded protein obvious – “the fact that a novel product can be readily made does not render the product not novel.”

The BPAI disagreed, stating that an invention need not have been actually made in the prior art for disclosure of such invention to be enabling. The BPAI noted that applicant did not dispute that the prior art was enabling for expression of the claimed polypeptide, and further distinguished over its prior decision in Lee v. Dryja. The BPAI pointed out that, in Lee v. Dryja, the issue was whether a party was in possession of a single enabled embodiment and, further, there was evidence in Lee v. Dryja that the disclosed nucleotide sequence did not, in fact, express the protein at issue.

The BPAI affirmed the examiner’s anticipation rejections and noted that there is no “generic rule that cDNAs cannot anticipate proteins.”

Takeaway: This case provides insight into how the USPTO has viewed the relationship between nucleotide sequences and the polypeptides they encode in the context of identifying enabling prior art. It is apparent that the BPAI would have required some evidence of obstacles preventing a skilled artisan from navigating from the disclosed cDNA to the claimed isolated polypeptide to reverse the examiner’s rejections. Of course, this case predates the Supreme Court’s recent eligibility jurisprudence, including Ass’n for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. 576 (2013), which likely would have even further complicated applicant’s quest for enforceable patent rights.

Judges: Grimes, Lebovitz, Fredman