Examiner Amendments Can Trigger Prosecution History Estoppel

In Amgen, Inc. v. Amneal Pharms. LLC, Appeal No. 18-2414, the Federal Circuit held that an examiner amendment may give rise to prosecution history estoppel, even when the examiner suggests the amendment in the absence of a pending office action.

Amgen sued multiple parties for infringement of a patent directed to pharmaceutical compositions useful for treating secondary hyperparathyroidism in adult patients with chronic kidney disease. After a bench trial, the district court held that some parties infringed, but others did not because the claims contained Markush groups of binders and disintegrants. The district court concluded that the Markush group made the entire claim closed ended with regard to the binders and disintegrants such that the presence of a binder or disintegrant in an alleged infringing product, if not recited in the Markush group, supported a finding of non-infringement. The district court also determined that prosecution history estoppel created by an examiner’s amendment, precluded the use of the doctrine of equivalents (“DOE”) with regard to the Markush groups.

The claim at issue used an open ended “comprising” preamble but contained two Markush groups. Each Markush group recited “at least one [binder/disintegrant] selected from the group consisting of …” The Federal Circuit reversed, determining that though one of the compounds in the Markush group must be present for infringement, other binder/disintegrate compounds were still permissible in an infringing product because of the plain language of the claim and the open ended preamble. Accordingly, the Federal Circuit remanded infringement to the district court.

The Federal Circuit upheld the district court’s ruling that prosecution history estoppel barred the use of DOE as it related to the Markush groups. The claims as originally filed did not contain the Markush groups. In response to an obviousness rejection, Amgen made certain amendments to the claims. In a subsequent interview, prior to issuing any further office action, the examiner proposed the Markush groups as an examiner’s amendment. Amgen agreed, and the claims were then allowed. Eight months later, in continued examination, Amgen filed a statement that the examiner’s amendment was not made to overcome a prior art rejection. Amgen argued that the presumption of prosecution history estoppel was overcome because the addition of the Markush groups was not necessary to secure allowance. The Federal Circuit rejected this argument because its implication was that the examiner’s amendment served no purpose, which was “at best unpersuasive.” The Federal Circuit also rejected the argument that Amgen’s comments on the examiner’s amendment during prosecution overcame the presumption because those comments were made well after the claims were allowed and were simply “conventional boilerplate” that provided no insight into the reasons for the examiner’s amendment.

Non-Prior Art Evidence May Be Used To Prove Inherency

In Hospira, Inc. v. Fresenius Kabi USA, LLC., Appeal No. 19-1329, the Federal Circuit held that evidence of the properties of claimed embodiments may be proper evidence of inherency, even when the evidence itself is not prior art.

Hospira sued Fresenius for infringement of a patent for its ready-to-use dexmedetomidine product (Precedex Premix). Following a bench trial limited to the validity of two claims, the district court concluded that one embodiment of claim 6 (the only claim at issue on appeal) was expressly taught in the prior art. The sole issue was a limitation requiring that the concentration of the active agent decrease by no more than 2%. Relying on fact and expert testimony related to the stability of both Hospira’s Precedex Premix and Fresenius’s generic product, the district court concluded the stability limitation was inherent, and found claim 6 invalid as obvious. Hospira appealed.

On appeal, Hospira argued that the district court erred in its application of the inherency doctrine by considering the inherent properties of non-prior art embodiments. Every tested sample in the record was either from Hospira’s Precedex Premix New Drug Application or Fresenius’s Abbreviated New Drug Application, neither of which was in the prior art. The Federal Circuit rejected Hospira’s argument, explaining that extrinsic evidence can be used to demonstrate what is “necessarily present” in a prior art embodiment even if the extrinsic evidence is not itself prior art.” The Federal Circuit also rejected Hospira’s argument that the district court erred by considering only samples made using a manufacturing process first described in the patent. The Federal Circuit explained that claim 6, which is not a method claim or product-by-process claim, included no limitations regarding the manufacturing process. Because importing such limitations into the claim would be improper, the district court did not err by considering samples without regard to the process by which they were prepared.

Hospira next argued that the district court erroneously applied to the inherency issue a lower “reasonable expectation of success” standard rather than the higher “necessarily present” standard. The panel rejected this argument as well. The Federal Circuit acknowledged that the district court unnecessarily analyzed whether a person of ordinary skill in the art would have had a reasonable expectation of success in achieving the “about 2%” limitation. However, that error “did not infect its inherency analysis and findings.” Unpersuaded by Hospira’s arguments, the Federal Circuit affirmed the district court’s conclusion that claim 6 was invalid as obvious.

No Appeal of PTAB’s Final Decision by Appealing a District Court’s Adoption of that Decision

In Personal Audio, LLC v. CBS Corporation, Appeal No. 18-2256, the Federal Circuit held that it has exclusive jurisdiction to hear a direct appeal of a PTAB’s final written decision of unpatentability. The Federal Circuit does not have jurisdiction to consider a challenge to the PTAB’s decision through an indirect appeal from the district court’s adoption of the PTAB’s decision.

Personal Audio sued CBS for patent infringement. After the case was filed, a third party petitioned for IPR. The district court case proceeded and a jury determined the asserted claims were valid and awarded damages. Subsequently, the PTAB issued a final written decision that the asserted claims were unpatentable. Personal Audio and CBS agreed to stay the district court proceedings pending review of the PTAB’s decision. Personal Audio appealed the PTAB’s final written opinion, the Federal Circuit affirmed, and the Supreme Court denied certiorari. After all of that, because of the PTAB’s final written decision, Personal Audio and CBS agreed that the district court should enter judgment in favor of CBS. Personal Audio then appealed the district court’s judgement to the Federal Circuit.

The Federal Circuit affirmed. In an appeal from a district court judgment, the Federal Circuit does not have jurisdiction to consider challenges to the validity of the PTAB’s decision. The court also determined that Personal Audio’s earlier direct appeal from the PTAB’s final written decision was adequate to adjudicate Personal Audio’s challenges. Further, Personal Audio forfeited any argument that the district court should not have entered judgment based on the PTAB’s final written decision. Personal Audio made no argument distinguishing cases holding that a district court action must terminate when a PTAB unpatentability ruling is affirmed on appeal.

PTAB Cannot Institute IPR on PTAB-Created Grounds

In Koninklijke Philips N.V. v. Google LLC, Appeal No. 19-1177, the Federal Circuit held that the Board can institute IPR only on grounds raised in a petition, and that the Board can rely on the general knowledge of a skilled artisan as of the priority date in evaluating obviousness

Google petitioned for IPR of a patent owned by Philips directed to forming a distributed multimedia presentation for a client device’s media player. In its petition, Google raised one obviousness ground based on a single prior art reference and the general knowledge of a skilled artisan. Google cited a second prior art reference and expert testimony as evidence of this general knowledge. The Board instituted IPR on both the ground raised in Google’s petition and a second ground of obviousness over the first prior art reference in view of the second prior art reference. The Board concluded that the claims were obvious based on both grounds, citing the same reasons, arguments, and evidence for both.

The Federal Circuit held that the Board erred in instituting on the second ground because it was not raised in Google’s petition. The court explained that the petition, and not the Board’s discretion, defines the metes and bounds of an IPR. With respect to the ground raised in Google’s petition, the Federal Circuit affirmed the Board’s finding of obviousness. The Federal Circuit acknowledged that prior art in an IPR is limited to patents and printed publications. It explained, however, that the obviousness inquiry under § 103 requires evaluation from the perspective of a skilled artisan, and such evaluation necessarily depends on the knowledge of a skilled artisan. It was thus proper for the Board to rely on such knowledge in its obviousness determination.