Composition claims are often rejected as obvious over the combinations of prior art referenced, that separately claim the ingredients of the claimed combination. Moreover, often the disclosure of the claimed ingredients is in the context of different chemical applications. In such cases, the obviousness determination frequently turns on whether one of ordinary skill in the art would have been motivated to combine the references to arrive at the claimed invention with a reasonable expectation of success. The inquiry is highly factual and can lead to different results, depending on the perspective of the fact finder. The Federal Circuit opinion in In re Ethicon —and Judge Newman's dissent—illustrate the difficulty of this inquiry. 844 F.3d 1344, 1354 (Fed. Cir. 2017).

Ethicon, Inc. ("Ethicon") owns U.S. Patent No. 7,591,844, which relates to drug-eluting stents, and methods for maintaining drugs on them. In relevant part, the claims are directed to "[a] device for intraluminal implantation in a vessel comprising a balloon-expandable stent and a pharmaceutical agent-containing coating, said coating comprising a biocompatible polyfluoro copolymer that comprises about eighty-five weight percent vinylidinefluoride [VDF] copolymerized with about fifteen percent hexalfluoropylene [HFP] . . . ." See '844 patent col. 37, l. 59-col. 38, l. 3. (Emphasis added). Ethicon sued Boston Scientific SCIMED ("Boston Scientific") and Abbott Laboratories ("Abbott") for infringement. In re Ethicon, 844 F.3d at 1354. Boston Scientific and Abbott filed separate requests for inter partes reexamination of the '844 patent. The Patent Office granted the reexamination requests and merged the proceedings. Id. In reexamination, the examiner rejected the relevant claims as obvious over, inter alia, U.S. Patent Nos. 5,824,048 ("Touch"), 4,816,339 ("Tu"), and 3,178,399 ("Lo").  Id.

Tuch, the primary reference, is generally directed to polymer coated drug-eluting vascular stents and names hundreds of monomers encompassing thousands of polymers and copolymers that may all be usable for vascular stents in various conditions. Id. at 1353 (Newman J., dissenting). Tuch, however, not disclose the specific copolymer claimed in the Ethicon patent. And although the list in Tuch discloses one of the monomers of the claimed copolymer (VDF), the other known monomer, HFP, is not mentioned. Id. Tu, in turn, describes a multilayered "suturable vascular implants" having "improved luminal hydrophobicity, compliance, strength and elasticity." Id. at 1355 (emphasis added).  The first layer is made of poly(tetrafluoroethylene), the second layer is "a mixture of poly(tetrafluoroethylene) and elastomer," and an optional third layer is made of "elastomer." Id. Tu states that the elastomer may be selected from a diverse group of polymers and copolymers, and VDF and HFP were listed among this list. Id. (citing to Tu, col. 4, ll. 30-39.). The Examiner relied on Tu "for teaching of a medical device comprising VDF:HFP," and further  relied on Lo to teach the VDF:HFP comonomer ratios claimed in the Ethicon patent. Id. at 1357. The Examiner also found unpersuasive Ethicon's evidence of objective indicia of non-obviousness. See id.

The Board affirmed the Examiner's rejection. Id. at 1348. The Board found that the primary reference's teachings would not have limited a skilled artisan to the explicitly listed polymers or dissuaded a skilled artisan from selecting a VDF copolymer. Id. The Board additionally found that the primary reference discloses "a problem with coatings with low elasticity," and that biocompatibility and elasticity are "useful" characteristics for the polymer in its stent coatings and that, therefore, one of ordinary skill in the art would have reasonably sought materials with high elasticity to avoid the problem when the stent is expanded." Id. Among other things, the Board agreed that Tu, one of the secondary references, teaches that VDF:HFP copolymer possesses the useful properties of biocompatibility and elasticity taught by Tuch. Id. The Board similarly agreed that Lo teaches that the claimed monomer ratio "is advantageous with respect to flexibility, elasticity, extensibility, tensile strength, and reverse elongation." See id. The Board agreed with the Examiner that Ethicon's evidence of nonobviousness was not entitled to substantial weight. Id.

On appeal, Ethicon first argued that Tuch never suggested that the elasticity of the polymer itself is an important characteristic and that it, in fact, taught away from using non-bioabsorbable coatings (such as VDF:HFP) by recommending bioabsorbable polymers. Id. The court rejected Ethicon's argument finding that Tuch teaches that elasticity is a useful polymer characteristic and that coatings with low elasticity are problematic. Id. at 1350. Second, Ethicon argued that Tu is directed to medical devices, other than stents, and teaches away from allowing an elastomeric polymer such as VDF:HFP to be in contact with blood. Id. at 1351. The court also rejected this argument, finding that Tu teaches that its invention has a "very broad application in biomedical devices, such as ... heart valve leaflets," Id. Third, Ethicon argued that Lo is decades old (over 50 years old), nonanalogous art directed to harsh industrial applications, as opposed to medical or biological applications, and provides no motivation to combine its teachings with the teachings of Tuch or Tu (dealing with implantable medical devices). Id. Thus, Ethicon essentially argued that the Board relied on impermissible hindsight and failed to provide any reason why one of ordinary skill in the art would have combined the prior art references to create the claimed invention.  Id. The court rejected this argument and determine that substantial evidence supports the Board's finding that Lo's teachings are at least "reasonably pertinent to the particular problem with which the inventors is involved," and stated that the mere age of a reference does not undermine the Board's otherwise proper reliance on it. Id.

The Court also rejected Ethicon's argument that the Board erred by discounting its proffered objective indicia of nonobviousness, because Ethicon relied solely on its expert's conclusory testimony to support its allegations. Id.

Judge Newman dissented concluding that there was no motivation to combine the references without hindsight and finding that the Board erred in declining to consider Ethicon's evidence of copying, commercial success, and medical industry acclaim. Id. at 1353. Judge Newman found that the main reference's omission of the specific copolymer claimed from the thousands of polymeric and other potential stent materials was problematic. According to Judge Newman, "the breadth of these choices and the numerous combinations indicate that these disclosures would not have rendered the claimed invention obvious to try." Id. at 1354 (citing LeoPharma Prods., Ltd. v. Rea, 726 F.3d 1346, 1356–57 (Fed. Cir. 2013)). Judge Newman further disagreed with the Board's combination of the references to arrive at the claims because the references failed to provide motivation to select specific polymer and monomer ratio claimed by Ethicon. See id.

According to Judge Newman, the Board merely collected the elements of Ethicon's patent claims from assorted sources, and improperly placed them in the template of Ethicon's patent. See id. at 1357(citing to Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed. Cir. 1985) ("The invention must be viewed not with the blueprint drawn by the inventor, but in the state of the art that existed at the time.").

Judge Newman also took issue with the Board's refusal to consider the evidence of superior properties and commercial success presented by Ethicon. The Board, for example, declined to consider the evidence without identifying what it would consider to be an acceptable prior art comparison. Id. To Judge Newman, the Board's refusal to consider this evidence, instead criticizing the "absence" of comparisons with some undefined prior art, is untenable. Id.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.