Testing the Limits of Inherent Obviousness in Patentability

March 28, 2019Articles The Legal Intelligencer

Patent applicants may be unfairly prevented from obtaining commercially valuable protection for a product, particularly during the patent procurement phase, due to recent trends in the application of the doctrine of inherent obviousness. In this article, we briefly review the doctrine of inherency, in the context of an obviousness rejection, as a bar to patentability.

Novelty and nonobviousness are the twin pillars of patent eligibility criteria in any patent regime. Simply put, an invention must be new and cannot be obvious in view of the teachings of prior art. A claim that fails to meet the novelty requirement of 35 USC Section 102 is said to be anticipated. Conversely, if the differences between the claimed subject matter and the prior art are of such a degree that the invention as a whole would have been obvious at the time a patent application was filed, the claims are determined to be obvious under 35 USC Section 103.

Novelty is typically a bar when a single prior art reference reveals each and every element in the claim for which a patent is sought. However, if that prior art reference does not explicitly teach each and every element of the claim, it can still anticipate a claimed invention through its inherent teachings, so long as the missing “characteristic is necessarily present or inherent, in the single anticipating reference,” as in Continental Can v. Monsanto, 948 F.2d. 1264, 1268 (Fed. Cir. 1991).

Merriam Webster defines inherency as “an inherent character or attribute,” while the word “inherent” is defined as “involved in the constitution or essential character of something: belonging by nature or habit: intrinsic.” Thus, to be inherent, the attribute or characteristic must already exist. For such reasons, “the discovery of a previously unappreciated property of a prior art composition, or of a scientific explanation for the prior art’s functioning, does not render the old composition patentably new to the discoverer,”as in Atlas Powder v. IRECO, 190 F.3d 1342, 1347 (Fed. Cir. 1999).

Under an inherent obviousness analysis, the existence of such an attribute or characteristic is merely assumed. In other words, one of ordinary skill in the art has to combine different prior art references to create the claimed invention in priori. If such prior art references are properly combined, then the intrinsic attribute or characteristic of the created combination must necessarily be present in the declared obvious invention.

In a real-life scenario, once an allegation of inherent obviousness is made at the patent office level, the burden shifts to the patent applicant or owner to disprove the allegation. During the prosecution of a patent application, the examiner reviewing the application has the initial burden of providing a basis in fact or technical reasoning for a proper showing of inherency. In doing so, the possibility that a certain result may occur, or a characteristic maybe present in the prior art would not be sufficient to establish the inherent existence of that result or characteristic. The precedent is clear that when a missing description of a prior art cannot be recognized by one of ordinary skill in the art, allegations based on “mere probabilities or possibilities” fall short of demonstrating that the missing element is necessarily present in the prior art reference, see In re Oelrich, 666 F.2d 578, 581-82 (CCPA 1981). Similarly, “an invitation to investigate” is insufficient to find inherency, as in Metabolite Laboratories of America Holdings, 370 F.3d 1354, 1367 (Fed. Cir. 2004). 

However, once the allegation of inherent obviousness is made on the basis of combining multiple references, the burden of production shifts to the applicant to prove that the declared obvious product does not necessarily possess the characteristics of the claimed product. At this juncture, the applicant faces the question as to what evidence is needed to rebut the allegation of inherent obviousness.

Assuming that the references are properly combinable, what is the requisite proof for a showing that the combined teachings of the prior art references cannot inherently provide for the missing claim element? What evidence is needed to rebut that the claimed missing property or functional element that is not present in the fictitious product? More importantly, what is the scientific threshold for meeting the “necessarily present” prerequisite? These are some of the questions faced by patent applicants seeking clearer standards.

The U.S. Court of Appeals for the Federal Circuit decisions regarding the inherent obviousness doctrine appear to rest on the premise that a missing element would be the natural result that occurs when one of ordinary skill in the art combines two or more pieces of prior art. “The concept of inherency must be limited when applied to obviousness, and is applied only when the claimed limitation at issue is the ‘natural result’ of the combination of the prior art elements,” see PAR Pharmaceutical v. TWI Pharmaceuticals, 773 F.3d 1186 (Fed. Cir. 2014). The judicial guidance is meticulous in describing that a “natural result” is realized when the claimed and prior art products are identical or substantially identical in “structure or composition” or where such structure or composition “are produced by identical or substantially identical processes …,” as in In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). Thus, when the prior art composition has the identical structural elements as the claimed invention, then any missing claim feature that is expressed in the form of a property or function of those structural elements would be a natural result, necessarily driven from the structural elements of the prior art. This is because “products of identical chemical composition cannot have mutually exclusive properties,” see In re Spada, F.2d 705, 7098 (Fed. Cir. 1990).

The same holds true when a structure or a composition is prepared by a substantially identical process as that in the prior art. When all of the process steps for manufacturing a claimed product are expressly disclosed in a prior art reference which does not disclose a property or a functional outcome, then, absent competent evidence or effective arguments to the contrary, such a missing property or functional outcome is inherently described in the prior art product. See e.g., Schering v. Geneva Pharmaceuticals., 339 F.3d 1373 (Fed. Cir. 2003) (finding that the known administration of a compound that invariably forms a metabolite may inherently anticipate a claim to the metabolite, even if formation of the metabolite was not recognized until years later).

In PAR Pharma, despite a ruling that there was a motivation to combine prior art references, the Federal Circuit remanded the case, stating that the district court’s inherent obviousness analysis was incorrect, because the record did not prove by clear and convincing evidence that the combination of references naturally resulted in the missing functional effect, which appeared to have been the basis for patentability. “The mere fact that a certain thing may result from a given set of circumstances is not sufficient.” Similarly, in Southwire v. Cerro Wire, 870 F.3d 1306 (Fed. Cir. 2017), the Federal Circuit rejected an analysis that lacked evidentiary support for a showing that a functional limitation (a reduction of 30 percent in the pulling force) would necessarily result from the claimed process.

The court’s logic in Millennium Pharmaceuticals v. Sandoz,862 F.3d. 1356 (Fed. Cir. 2017) is different because the disputed claims were not limited as to a function or characteristic. In that case, the Federal Circuit reasoned that a known process (lyophilizing), would not inherently produce a previously unknown compound (the D-mannitol ester of bortezomib), because the prior art did not disclose the compound. The court rejected the obviousness conclusion for lack of suggestion of the unknown compound even though the natural flow from the known process steps (lyophilization of the prior art compound with mannitol) may have produced the unknown product.

In Endo Pharmaceuticals Solutions v. Custopharm, 894 F.3d 1374 (Fed. Cir 2018), the Federal Circuit affirmed a finding that the presented claims were not inherently obvious in light of prior art references, because the knowledge about the existence of a claimed component was not expressly disclosed in the prior art. In Honeywell International v. Mexichem Amanco Holding, 865 F.3d 1348 (Fed. Cir. 2017), the court reversed an earlier PTAB decision, finding that it improperly dismissed the claimed properties as merely inherent, without considering their unpredictability and unexpectedness. Even though all properties of a composition may be inherent in that composition, “unexpected properties may cause what may appear to be an obvious composition to be nonobvious.”

These Federal Circuit decisions provide some clarity on what is not inherently obvious. But what evidence is needed to show that a combination of references does not naturally result in the missing functional attribute or characteristic limitations? If the claimed product or process is not the only product or process that could necessarily be made following the teachings or suggestion of the prior art, then the claimed invention is not inherently obvious. Millenniumsuggests that unknown products prepared by known processes are not inherently obvious. The recent trends suggest an increase in the use of inherent obviousness in rejecting patent applications. Even though the burden of asserting the inherent obviousness allegation may seem fair, the hurdles one must overcome to disprove the theory of inherency are much higher than those required of the examiner asserting inherency. The USPTO’s inability to manufacture or compare products has been used as the justification for this shifting of burden, however, this undoubtedly puts an unduly onerous burden on the inventors, who may themselves have limited resources. As advances in scientific inventions become increasingly incremental, judicial guidance is particularly important on the issue of inherent obviousness as a bar to patentability.

Reprinted with permission from the March 28 issue of The Legal Intelligencer. (c) 2019 ALM Media Properties, LLC. Further duplication without permission is prohibited. All rights reserved.