Recent CAFC Decisions Teach That "Teaching Away" Is Difficult To Establish When Responding to Obviousness Assertions

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While “teaching away” is often considered and invoked as a strategy for responding to an assertion of obviousness, its success is less common, with “teaching away” having a high bar to show discouragement or that a resulting combination would not work. It is well-established that “[a] reference may be said to teach away when a person of ordinary skill, upon reading the reference, would be discouraged from following the path set out in the reference, or would be led in a direction divergent from the path that was taken by the applicant.”[i] Recent decisions of the U.S. Court of Appeals for the Federal Circuit (CAFC) in Fleming v. Cirrus Design Corporation[ii]and Adapt Pharma Operations Limited v. Teva Pharmaceuticals USA, Inc.[iii] demonstrate this high bar.

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The decisions in Fleming and Adapt Pharma reinforce that while it is not required that the prior art show definitively and distinctly that a claimed invention is impossible, inoperable, etc., the evidence required to meet the bar of ‘discouraging a person having ordinary skill in the art (PHOSA) from pursuing the invention, or leading the PHOSA down a path divergent from that taken by the applicant’ remains significantly high.[iv] It is clearly not sufficient to only discourage the pursuit of an invention similar to that which is claimed, one must show evidence that the prior art distinctly discourages the use or implementation of a claimed element exactly as it appears in the claim and be commensurate in scope with the ultimate claims at issue.[v]

In Adapt Pharma, the CAFC affirmed a district court finding that claims of several patents would have been obvious over the prior art. The claims at issue relate to a method of treating an opioid overdose using a “single-use, pre-primed device adapted for nasal delivery…” of a drug composition, the composition comprising naloxone in an amount of about 4 mg, an isotonicity agent in an amount of about 0.2 mg to 1.2 mg, a preservative in an amount of about 0.005 mg to 0.015 mg, a stabilizing agent in an amount of about 0.1 mg to 0.5 mg, and an amount of acid sufficient to achieve a pH of 3.5-5.5.  

There were two groups or combinations of references that were asserted to render the claims obvious, and of note is the claimed amount of preservative. Adapt Pharma challenged Teva’s assertion of invalidity on multiple grounds, including by asserting that the prior art teaches away from the claimed composition.

In arguing for the validity of the claims, Adapt Pharma cited evidence that taught that a preservative, benzalkonium chloride (BZK), in an amount of 0.125% w/v (i.e. 8.5 times greater than the concentration claimed) led to degradation of naloxone. Thus, Adapt Pharma argued BZK was taught to be unsuitable for use in intranasal naloxone formulations, therefore discouraging the use of BZK. The district court, based in part on expert testimony, held that the reference would not have discouraged or led a skilled artisan down a path divergent than that taken by the applicant, particularly considering a showing that BZK is one of the most common preservatives in nasal formulations, and two other prior art references disclosed naloxone formulations that used BZK as a preservative. Rather, the district court found that the teaching of degradation of naloxone in the presence of high concentrations of BZK would only dissuade one from using such high concentrations, and the CAFC found that the district court did not commit clear error in its finding.  Thus, while the patent owner showed evidence BZK may cause naloxone degradation, the concentration differences between such evidence and the claims give rise only to a “teaching away” that was not “commensurate in scope” with the claims at issue,[vi] and the presence of other references (at the claimed concentrations) constituted conflicting teachings. Indeed, as cited by the District Court, “[w]here the prior art contains ‘apparently conflicting’ teachings (i.e., where some references teach the combination and others teach away from it) each reference must be considered ‘for its power to suggest solutions to an artisan of ordinary skill.... consider[ing] the degree to which one reference might accurately discredit another.’”[vii]  

In Fleming, the CAFC affirmed a Patent Trial and Appeal Board’s (“PTAB”) finding that claims 137-139 of U.S. Patent No. RE47,474 (“the ’474 patent”) were obvious. 

The ’474 patent is directed to ballistic parachute systems on an aircraft. It claims an aircraft comprising, inter alia, a whole-aircraft ballistic parachute, and an activation interface, wherein the aircraft is configured to receive a parachute deployment request, and perform an action and also deploy the parachute.

Fleming argued that the prior art teaches away from the invention as the alleged combination of references would be unsafe. Fleming argued that the prior art taught that autopilot should not be used in emergency situations and cited teachings that autopilot use is not advisable for takeoff and landing or when the aircraft does not have a sufficient altitude.

However, the CAFC concurred with the PTAB that the prior art did not dissuade one from using an autopilot system to deploy a ballistic parachute system for all aircraft and in all situations.  Instead, the CAFC found a reasonable fact finder could conclude that the prior art does not suggest to the skilled artisan that an autopilot should never be used in any emergency situation for any aircraft, as Fleming contended. For example, one prior art document disclosed that the continuous use of an autopilot is of particular benefit for unmanned aerial vehicles, while another disclosed that the use of the ballistic parachute system “would be appropriate” in the event of pilot incapacitation, suggesting use of an autopilot to deploy the ballistic parachute system. That the prior art cautioned pilots not to use an autopilot in some emergency situations on some aircraft does not mean that the skilled artisan would have been dissuaded from doing so in all emergency situations on all aircraft. Accordingly, the CAFC agreed that substantial evidence supported the PTAB’s finding that the prior art, rather than teaching away, merely taught a less preferable embodiment. The fact that the combination of the prior art in this case might be unsafe, would not render the invention unfeasible.

These decisions in Adapt Pharma and Fleming, as well as many others, serve as reminders that the requisite showing to prove a “teaching away” requires a strong discouragement away from the claimed invention. Because such a showing is often difficult, it begs the question if the argument may face better odds if it can be stated another way.  For example, practitioners may have more success using the same set of facts to argue that a PHOSA would not have had a reasonable expectation of success in carrying out the invention. The standard for finding that a PHOSA would not have had a reasonable expectation of success was clarified in the recent decision in University of Strathclyde v. Clear-Vu Lighting LLC.[viii] In Strathclyde, previously reported on,[ix] the CAFC overturned a PTAB finding of obviousness, stating that the facts of the case would lead a PHOSA to the conclusion that “the only reasonable expectation at the time of the invention was failure, not success.” In fact, Circuit Judge Newman dissented in Adapt Pharma, and commented that the very teaching dismissed by the CAFC was the “epitome of ‘teaching away’.” Disregarding the concentration differences, as well as the prior art disclosing other naloxone products containing BZK, she urged that “[i]t cannot be found that the prior art provided a reasonable expectation of success in use of BZK in this naloxone composition, when the prior art explicitly warned that BZK causes unacceptable naloxone degradation.”  Similarly, Fleming may have had a greater chance of success at arguing that the potentially unsafe flight conditions for use of a ballistic parachute taught in the prior art may have led a PHOSA to believe there would not have been a reasonable expectation of success in implementing the claimed whole-aircraft ballistic parachute and activation interface of the ’474 patent.  Given the relatively few cases where “teaching away” is a winning argument, patent applicants and owners may be better served to consider whether arguments directed to a “reasonable expectation of success,” or lack thereof, may compliment or replace a strategy based upon “teaching away.”