interchangeable equivalents Archives

Last December, in Modernatx, Inc. v. Arbutus Biopharma Corp., 18 F.4th 1364 (Fed. Cir. 2021), Moderna, in appealing their challenge to an Arbutus patent in an inter partes review, contended that the Board had erred in dismissing their case because it failed to apply a presumption of obviousness based on overlapping ranges in the prior art. While Moderna admitted that not all of the claimed ranges of the Arbutus components were explicitly disclosed in their cited art, they contended that the single missing range could be calculated based on the other ranges and on the “axiomatic” concept that the total of all components must be 100%. The Federal Circuit disagreed.

While the court acknowledged that it had, in the past, found that a presumption of obviousness exists “when the ranges of a claimed composition overlap the ranges disclosed in the prior art,” it found that, in this case, it was undisputed that a range for one of the components was not expressly “disclosed.” Recognizing that it was also true that the court had never affirmatively decided whether the presumption could apply in a case such as this, the court nevertheless declined to make that decision here “because this case turns on a narrower issue, specifically, Moderna’s failure to show that the overlapping range is actually taught by the prior art.”

In dismissing Moderna’s seemingly reasonable theory of overlapping ranges using a calculated missing range the court found that “[o]ne of the key flawed assumptions that Moderna makes is that the amount of each individual … component in the prior art … can be freely manipulated and adjusted across the full scope of the disclosed ranges” and that, as a corollary, Moderna “assumes that any … component … can be increased as long as any … component … is decreased by a corresponding amount to maintain a total of 100%.” The court came to this position because Arbutus had put forth a “plethora of evidence, including evidence from the prior art references as well as expert testimony” demonstrating that “this case is not that simple because the … components … are interdependent, … they interact with each other unpredictably” and “as a whole, rather than on any one component.” The court then reminded Moderna that even in prior cases with fully, explicitly disclosed overlapping ranges involving multiple components “we have held that evidence that the components interacted in an unpredictable or unexpected way could render the combination nonobvious,” emphasizing in the opinion that such earlier holdings apply even more strongly here, where Moderna’s assumptions necessary to derive the unstated/implicit overlapping range are themselves undermined by the unpredictable interactivity between the components.

Takeaway: Because a rejection involving overlapping ranges can give rise to a presumption of unpatentability which puts the burden of going forward on applicant/patentee, it must be vigorously contested. The several ways in which Arbutus “fought off” the presumption in the Moderna case provide an instructive framework for traversing such rejections.

Judges: LOURIE, O’MALLEY, and STOLL

On February 28, 2022, the Patent Trial and Appeal Board (PTAB) issued a decision in Ex parte Chen (Appeal 2021-001752) affirming an Examiner’s rejection of claims directed to a polyisocyanurate foam composition comprising a certain two-component blowing agent.

In making the rejection, the Examiner used the same technique used in Almirall, LLC v. Amneal Pharm., No. 2020-2331 (Fed. Cir. Mar. 14, 2022) (discussed here) – she applied a primary reference disclosing one of the claimed blowing agent components and combined it with a secondary reference disclosing an expansive laundry list of blowing agent components that partially overlapped with species described in the primary reference and which, importantly, included the claimed blowing agent component missing from the primary reference. In justifying the combination, the Examiner took the position that because all the blowing agent components in the laundry list were “interchangeable and equivalent” it would have been obvious to substitute one of the overlapping components in the primary reference with the missing component.

Applicant traversed the rejection in three different ways in their Brief. First, they argued that neither reference, on its own, rendered the claims obvious (never a good idea in an obviousness rejection based on two references). Next, they asserted that because the primary and secondary references focused on different types of blowing agents one of ordinary skill in the art would not have combined the references. And finally, they argued that the data submitted during prosecution showed unexpected synergy for their blowing agent composition at their claimed ratios.

The Board, in its decision affirming the Examiner, ignored the first argument, rejected the second argument as lacking evidence and support, and found the data submitted during prosecution to be insufficient because it did not show the beneficial trend asserted and was not commensurate in scope with the claims.

Takeaway: Unfortunately, and as we learned in our prior blog on Almirall, where Applicant went wrong in this case was in not fleshing out its non-combinability argument. The primary and secondary references did indeed focus on different types of blowing agents – saturated v. unsaturated. A declaration explaining why the co-blowing agents listed in each reference were specially tailored for use with only one of these types of agents, and an explanation why only the few overlapping agents could be used with both types, might well have overcome the rejection.

Judges: J. Robertson, M. Cashion, Jr., S. McGee

Last month, in Almirall, LLC v. Amneal Pharm., No. 2020-2331 (Fed. Cir. Mar. 14, 2022) the Federal Circuit affirmed the Board’s holding of obviousness in an inter partes review. In Almirall the main issue in the case was the absence, in the primary reference, of the claimed gelling agent.

Petitioner, in asserting obviousness, used a secondary reference that disclosed both the claimed gelling agent and the gelling agent of the primary reference in a “laundry list” of ten broad types, or classes, of gelling agent useful in the secondary reference. Importantly, Petitioner also included substantial expert testimony characterizing the claimed gelling agent and the gelling agent of the primary reference as being “closely related,” as capable of being “interchangeably used” in the claimed formulations “in the same concentration range,” that such a substitution was “routine and predictable,” and that one of ordinary skill in the art “would not have expected any incompatibilities.”

Patentee, unable to successfully counter this mountain of evidence, was left to argue at the margins, and focused on the non-overlapping concentration ranges of gelling agents used in the primary and secondary references. However, the Court was having none of it:

Ultimately, despite Almirall’s attempts to argue otherwise, this case does not depend on overlapping ranges. It is simply a case of substituting one known gelling agent for another. Each may be effective at a different concentration in different formulations, but that is just a property of the particular known material, subject to conventional experimentation.

Takeaway: The Almirall case is interesting because the initial “hook” that led to the finding of obviousness was one that Examiners use in rejecting claims all the time: a secondary reference with an expansive laundry list of agents that includes both the claimed agent and the agent of the primary reference. The difference between the inter partes review in Almirall and regular prosecution, however, is that during prosecution the Examiner simply alleges interchangeability based on the common listing, without more, while in Almirall Petitioner submitted substantial evidence regarding combinability, interchangeability, and expectation of success. The Almirall case thus provides applicants with a good example of the type of evidence, albeit in the reverse, to submit in traversing such rejections during prosecution.

Judges: Lourie, Chen, Cunningham

In Ex parte Sharma (Appeal 2020-004468), the Patent Trial and Appeal Board (“Board”) considered the Examiner’s obviousness rejection of Appellant’s claimed method of treating once-through steam generator (OTSG) blowdown water for reuse based on “equivalents” allegedly described in a secondary reference.

Claim 1 was representative and the claimed method included, among other steps, a step of “settling precipitants out of said OTSG blowdown water for at least 12 hours to produce an acid clarified blowdown water having more than 50% of the acid insoluble organics removed.”

The Examiner found that Bansal, the primary reference, described a method of treating OTSG blowdown water by separating the solids from the liquid via a centrifuge and admitted that Bansal did not teach that solids and precipitants were settled out for at least 12 hours as claimed. However, the Examiner alleged that Cote, the secondary reference, described various equivalent separation devices, including settling ponds and centrifuges. The Examiner thus alleged claim 1 would have been obvious over Bansal in view of Cote.

Appellant countered that Cote did not teach that pond settling was “equivalent” to Bansal’s high speed centrifuging and particularly pointed out that the high pressure centrifuges described in Bansal exerted 3000-3500 times the force exerted in a settling pond.

The Board noted Cote disclosed that solids generated during wastewater processing of a phosphogypsum pond processes “may be removed by one or more suitable solids separation devices such as a clarifier, settling pond, lamella clarifier, upflow sludge blanket clarifier, disk filter, centrifuge, vacuum filter, dissolved air floatation device or the like.” According to the Board, Cote’s statement that “one or more” of these separation devices could be used only indicated that settling and centrifuges were both solids separation devices, but “not that they are equivalent.” Instead, as the Board continued, “the suggestion is that settling and centrifugation are complementary approaches that may be used in combination.”

Further, as the Board noted, Bansal disclosed that the smaller size and relative softness of the solids described therein limited the ability to separate liquid and solid phases by conventional centrifuging or hydrocycles and that the oily organics further limited ability to utilize filtering since the particles tended to stick together agglomerating and clogging filter media. Therefore, the Board found Bansal indicated that settling would not work in its process.

Citing In re Ruff, the Board emphasized “[t]hat two things are actually equivalents, in the sense that they will both perform the same function, is not enough to bring into play the rule that when one of them is in the prior art the use of the other is obvious and cannot give rise to patentable invention” and “[t]o rely on equivalence as a rationale supporting an obviousness rejection, the equivalency must be recognized in the prior art, and cannot be based on an applicant’s disclosure or the mere fact that the components at issue are functional or mechanical equivalents.”

Because the Examiner erred by finding that the prior art recognized settling and centrifugation as equivalents, the Board concluded one of ordinary skill in the art would not be expected to substitute settling for Bansal’s high pressure centrifugation and reversed the Examiner’s obviousness rejection.

Takeaway: As noted in Mat Barnet’s prior blog on interchangeable equivalents, for a component missing from a primary reference, U.S. patent examiners usually cite a secondary reference disclosing the missing component and resort to the rationale of simple substitution by alleging that the substituting component disclosed in the secondary reference is equivalent to one of the components in the primary reference (i.e., the substituted component). One justification for the substitution the examiners often rely on is that the secondary reference describes various components, including both the substituting and substituted components, by using terms such as “include,” “one or more,” and “at least one.” As illustrated by Sharma, such description alone cannot justify the substitution rationale. Instead, the equivalency must be described in the prior art references so that it is recognized by one of ordinary skill in the art in light of the prior art description.

Judges: G. C. Best, D. M. Praiss, D. L. Dennett

On April 2, 2020, the Patent Trial and Appeal Board issued a decision in Ex parte Humphrey reversing an Examiner’s obviousness rejection because the Examiner’s factual finding that a prior art method involving the reaction of a chain extender suggested a reaction involving a combination of different chain extenders was erroneous. No. 2019-004118 (P.T.A.B. Apr. 2, 2020) (non-precedential).

Speaking of Overlapping Ranges…

Speaking of Overlapping Ranges…

Oh, and about that Laundry List…

Inclusion in “Laundry List” Supportive of Interchangeability

Are They Equivalents?

Prior Art Disclosure of Interchangeable Chemical Species Insufficient to Teach Their Combination

USPTO Withdraws Proposed Terminal Disclaimer Rule

USPTO Further Delays Non-DOCX Fee Until January 17, 2024