Insight Into Amending Claims in an Inter Partes Review

February 24, 2015

Azy 2.24.15

The Patent Trial and Appeal Board (“PTAB”) allowed what appear to be the second and third amendments in an inter partes review (“IPR”) in Riverbed Technology, Inc. v. Silver Peak Sys, Inc., IPR Nos. 2013-00402 (Paper No. 35) and 2013-00403 (Paper No. 33); the first being in response to an unopposed Motion to Amend in International Flavors & Fragrances Inc. v. United States, 2013-00124 (Paper No. 12).  The PTAB has not granted many Patent Owner’s request to amend claims based on a rigorous standard as set forth in PTAB’s previous decisions (see e.g., Idle Free Sys., Inc. v. Bergstrom, Inc. IPR2012-00027 (Paper No. 66)), but the PTAB’s pair of decisions on December 30, 2014, provides some insight on how to meet the PTAB’s high bar in amending claims.

Riverbed Technology, Inc. (“Riverbed”) filed an IPR challenging Silver Peak Systems Inc.’s (“Silver Peak”) memory patents.  Silver Peak did not file a Patent Owner Response, but instead filed a Motion to Amend, seeking to cancel claims and substitute new claims in their place.  (IPR No. 2013-00403 Paper No. 23 and IPR No. 2013-00402, Paper No. 25).  The PTAB concluded that “by a preponderance of the evidence, [ ] proposed substitute claims [ ] are patentable over the prior art.” (IPR No. 2013-00403, Paper No. 33, p. 27 and IPR No. 2013-00402, Paper No. 35, p. 27).

In reaching its decision, the PTAB determined that the proposed substitute claims did not enlarge the scope of the original patent claims as it included all of the limitations of the original claims and included additional limitations of “fine and coarse filtering of hash values” and “forward and backward memory comparison.” The PTAB further found the claims had sufficient written description support.  However, neither of these requirements was challenged by the Petitioner.

The Petitioner did challenge the patentability of the substitute claims, first arguing that the Patent Owner only attempted to distinguish the proposed claims over the prior art references at issue in the IPR and not all the prior art known to the Patent Owner.  (IPR No. 2013-00403 Paper No. 33, p. 16 and IPR No. 2013-00402, Paper No. 35, p. 16).  The PTAB disagreed, stating that the Patent Owner addressed prior art of record and ones in which Patent Owner was generally aware of.  In addition to the prior art cited by the Petitioner, the Patent Owner explained the patentability of its claims over the “Spring reference” and references cited in the Petitioner’s White Paper– neither of which were the basis for instituting the IPR (although at least the Spring reference was cited during the prosecution history of the patent applications). The PTAB held that a sufficient explanation and technical reason was given for why the proposed substitute claims were patentable over the “prior art of record and the prior art of which Patent Owner is aware.”  (IPR No. 2013-00403 Paper No. 33, p. 16 and IPR No. 2013-00402, Paper No. 35, p. 16).

Second, the Petitioner argued that the Patent Owner failed to meet its burden to show the claims were patentable over the prior art because it did not provide a declaration from a technical expert in support of its arguments.  The PTAB likewise rejected this argument, stating that “[t]estimony from a technical expert certainly can be helpful to show what would have been known to a person of ordinary skill in the art, [but] it is not a perquisite for a motion to amend.  (IPR No. 2013-00403 Paper No. 33, pp. 25-26; and IPR No. 2013-00402, Paper No. 35, pp. 24-25).  The PTAB concluded that “[u]nder the particular factual circumstances of this case, we determine that Patent Owner has provided a sufficient explanation of why proposed substitute claims [  ] are patentable over the prior art, without reliance on testimony from a technical expert.”  Id. 

The Riverbed decisions make clear the importance that the Patent Owner show patentability of its substitute or amended claims over references that the Patent Owner is generally aware of, including any references that do not form the grounds of unpatentability in the PTAB’s decision to institute the IPR. Patent Owners are not required to show patentability of all prior art that has ever existed, but addressing at least one reference that was not relied upon in the Decision to institute IPR appears to be helpful in granting a motion to amend.


Azy Kokabi


Azy Kokabi focuses her practice on patent infringement litigation in Federal Courts, with particular experience in Hatch-Waxman patent infringement litigations. Ms. Kokabi’s practice also involves patent office trials, with a particular emphasis on inter partes review. Ms. Kokabi, a registered patent attorney, has served as counsel in multiple interference proceedings and related matters, before the Board of Patent Appeals and Interferences and the Court of Appeals for the Federal Circuit.

Ms. Kokabi also prosecutes patent applications covering biotechnology and medical devices, and has been involved in a number of reexamination proceedings and reissue applications before the United States Patent and Trademark Office. Prior to joining Sughrue Mion, Ms. Kokabi worked at a boutique law firm, where she focused on interference practice. She also served at the U.S. Patent and Trademark Office as an Examiner, where she was responsible for examining patent applications related to medical devices and surgical bandages and interned for the Honorable Judge Rader at the Court of Appeals for the Federal Circuit.