The US Court of Appeals for the Federal Circuit upheld an inter partes review (IPR) determination that challenged claims were not obvious over two references asserted in requestor's IPR petition without consideration of other prior art made of record in the proceedings. Sirona Dental Systems GmbH v. Institut Straumann AG, et al., Case Nos. 17-1341; -1403 (Fed Cir., June 19, 2018) (Moore, J).

Sirona owned a patent directed to a method for producing a drill template to precisely place a dental implant using image markers. Institut Straumann challenged the patent in an IPR petition that set forth three grounds of invalidity. In this pre-SAS case, the Patent Trial and Appeal Board (PTAB) instituted on two of the three grounds. Sirona filed a contingent motion to amend that petitioner opposed, arguing the proposed substitute claims would have been obvious over additional prior art not relied on in the instituted grounds. In its final written decision (FWD), the PTAB concluded that several challenged claims would have been obvious in view of the prior art asserted in the original petition, while petitioner failed to meet its burden with respect to other asserted grounds. The PTAB also denied Sirona's motion to amend, concluding that it failed to show that the proposed substitute claims were patentable over a combination of prior art, including the art cited in petitioner's opposition. Both parties appealed.

As to the groups of claims that the PTAB concluded were obvious, the Federal Circuit affirmed based on the substantial evidence test. 

As to the group of claims that the PTAB found had not been proven to be unpatentable, petitioner argued that the PTAB "should have applied findings from its analysis of Sirona's contingent motion to amend," where the PTAB found that the prior art presented in the opposition contained the teaching that the PTAB found lacking in the asserted prior art from the original petition. The Federal Circuit rejected the contention as an attempt to add references to the originally asserted grounds on asserted invalidity: "We see no error in the Board's decision not to decide grounds of unpatentability not raised in the petition."

Finally, the Federal Circuit reversed the PTAB's denial of Sirona's contingent motion to amend, finding that the PTAB "improperly placed the burden on Sirona to demonstrate that the proposed substitute claims were patentable." On that issue, the FWD was vacated and remanded for the PTAB to reconsider in light of the intervening en banc Federal Circuit decision in Aqua Products (IP Update, Vol. 19, No. 8).

Sirona had also argued that the FWD improperly rejected the proposed substitute claims based on a combination of references not raised by petitioners, and that "even if the Board could rely on a combination of references not raised by Petitioners, [it] did not receive notice and an opportunity to respond to the combination of references the Board relied on, as required under the [Administrative Procedure Act]." The Federal Circuit declined to address this issue, instead instructing the PTAB to "determine in the first instance, in light of recent precedent including SAS Institute, Inc. v. Iancu, [ IP Update, Vol. 21, No. 5] whether it may consider combinations of references not argued by the petitioner in opposing the motion to amend claims, and, if so, what procedures consistent with the APA are required to do so."

PTAB Need Not Consider Prior Art Of Record Not Relied On In IPR Petition

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