A recent ruling from the Patent and Trial Appeal Board (PTAB) highlights the critical role that collateral estoppel (also known as issue preclusion) can play in inter partes review (IPR) proceedings. In a final written decision issued on January 13, 2020, the Board determined that Petitioner Rimfrost AS had shown, by a preponderance of the evidence, that the challenged claims of Aker Biomarine Antarctic AS's U.S. Patent No. 9,375,453 (the "'453 Patent") are obvious. (The Board reached the same conclusion with respect to Aker's proposed substitute claims and therefore also denied Aker's contingent motion to amend.) The Board based its decision in part on its finding that Aker was collaterally estopped from asserting two "reasonable expectation of success" arguments against Rimfrost's obviousness attack, since Aker had unsuccessfully raised those same arguments, no less against the same prior art, in previous IPR proceedings involving different patents within the '453 Patent's family.
The '453 Patent is directed to methods for extracting and processing polar krill oil from Antarctic krill, which are small fish that contain bioactive fatty acids. According to the '453 Patent, krill oil compositions have been found effective for treating several conditions, including (among others) high cholesterol, plaque formation, hypertension, arthritis and skin cancer. Representative independent Claim 1 recites a method for producing polar krill oil by (1) treating the krill to denature its lipid enzymes; (2) using a polar solvent to extract oil comprising specific ratios of ether phospholipids, non-ether phospholipids, triglycerides and astaxanthin esters; and (3) formulating the processed oil in capsules suitable for oral consumption.
Rimfrost filed an IPR challenging the patentability of claims 1 through 32 of the '453 Patent, arguing that they are obvious under 35 U.S.C. § 103(a). In its Petition, Rimfrost identified four different prior art combinations that purportedly disclosed the recited method of producing krill oil with the recited composition. The Board instituted trial on all four combinations.
In its Patent Owner Response, Aker did not dispute whether the asserted prior art references individually disclosed the methods and recited components of the krill oil, as set forth in the '453 Patent. Aker instead contended that a person of ordinary skill in the art would not have thought to combine those references with a reasonable expectation of successfully arriving at the claimed invention. Specifically, Aker presented three arguments for why an ordinarily skilled artisan would not have held a reasonable expectation of success, including (as the Board labeled them), (1) the "no triglycerides" argument, (2) the "PAF teaching away" argument, and (3) the "combining extraction techniques" argument. In its Reply, Rimfrost asserted that Aker was collaterally estopped from raising the first two arguments because it previously advanced them—unsuccessfully—in separate IPRs involving related patents. (Rimfrost did not attack the third argument on collateral estoppel grounds, but rather challenged it on the merits.)
The Board ultimately agreed with Rimfrost regarding the applicability of collateral estoppel to Aker's "no triglycerides" and "PAF teaching away" arguments. The Board explained that collateral estoppel precludes a party from relitigating an issue if "(1) [a] prior action present[ed] an identical issue; (2) the prior action actually litigated and adjudged that issue; (3) the judgment in that prior action necessarily required determination of the identical issue; and (4) the prior action featured full representation of the estopped party." Paper 34 at 1-2 (quoting VirnetX Inc. v. Apple, Inc., 909 F.3d 1375, 1377 (Fed. Cir. 2018)). As the Board further stressed, "[t]he application of collateral estoppel is not limited to patent claims that are identical." Id. at 31. "Rather, it is the identity of the issues that were litigated that determines whether collateral estoppel should apply," such that "[i]f the differences between the unadjudicated patent claims and the adjudicated patent claims do not materially alter the question of invalidity, collateral estoppel applies." Id. (quoting Ohio Willow Wood Co. v. Alps S., LLC, 735 F.3d 1333, 1342 (Fed. Cir. 2013)) (emphases added).
Applying these standards, the Board found collateral estoppel applicable even though the prior IPRs involved different patents and claims. The Board observed that the patents in the prior proceedings were part of the same family and recited many of the same limitations as the '453 Patent. The prior proceedings also involved the same prior art references. And Aker had made the exact same obviousness arguments. The Board thus determined that, for purposes of collateral estoppel, the identical issues had been actually litigated and adjudged in the prior IPRs. The Board next found that the patentability analyses in the prior proceedings necessarily required rejection of Aker's "no triglycerides" and "PAF teaching away" arguments. And since Aker indisputably had been fully represented in those proceedings, the Board concluded that Aker was estopped from relitigating its "no triglycerides" and "PAF teaching away" theories.
The Board then considered Aker's third "combining extraction techniques" argument and rejected it on the merits, for many of the same reasons that it was rejected in the previous IPRs. The Board therefore ruled that Rimfrost had met its burden in proving that the claims of the '453 Patent are obvious.
Practice Tip: Where an IPR concerns a patent within the same family as, or otherwise related to, a patent that was at issue in a prior IPR, the patent owner should be careful not to rely too heavily (if at all) on arguments that the Board rejected in the earlier proceeding. Even if the challenged claims are not identical to those asserted in the prior IPR, there is a good chance that the Board will bar any such arguments in the new proceeding under the doctrine of collateral estoppel, so long as the Board finds that the issues previously adjudicated are the same.
Rimfrost AS v. Aker Biomarine Antarctic AS, IPR2018-01178, Paper 34 (PTAB Jan. 13, 2020)
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