Federal Circuit Makes it Easier to Amend Patent Claims in Post-Grant IPR Challenges

It is fairly common nowadays for a party accused of patent infringement to file a petition in the United States Patent and Trademark Office requesting Inter Partes Review (“IPR”) of the asserted patent. This is a procedure for challenging the validity of the asserted patent based on prior art consisting of patents or printed publications. The review is conducted by the Patent Trial and Appeal Board (PTAB). IPRs are popular among accused infringers, not only because they may possibly avoid expensive litigation, but also because there are advantages to accused infringers over district court litigation. These advantages to the accused infringer include:

  • A lower burden to establish invalidity. In district court litigation, a patent is presumed to be valid and proof of invalidity must meet the clear and convincing standard.1  In an IPR proceeding, invalidity can be shown by the lower preponderance of the evidence standard.2
  • A broader standard for claim construction. District courts construe patent claims under a most reasonable standard as described in Phillips v. AWH Corp.3 The PTAB construes claims under the broadest reasonable interpretation (BRI), which makes it easier to invalidate the claims.4
  • The PTAB is the finder of facts. In district court litigation the finder of disputed facts is a jury of lay individuals that may be reluctant to substitute their own opinions for those of the PTO Examiner who allowed the patent.  In an IPR, the finder of facts is a panel of Administrative Patent Judges, many with technical backgrounds, who are less likely to defer to the original Examiner.
  • More likely to prevail. Because of the lower standard of proof and broader standard for claim construction, there is a greater likelihood of invalidating a patent through an IPR proceeding.
  • Less expensive than litigation. With a truncated schedule, limited discovery and review limited to validity of the patent based on prior art publications, IPRs are typically significantly less costly than district court litigation.
  • Basis for stay if in litigation. If a lawsuit has been initiated and is still in its early stages, the filing of an IPR petition and especially the grant of an IPR petition may be sufficient grounds for the judge to stay the litigation pending resolution of the IPR. If the patent claims are invalidated in the IPR, the lawsuit will be dismissed.

The use of the BRI standard has been justified because, in theory, the Patent Owner has an opportunity to amend the patent claims if needed to distinguish the claims over the prior art presented in the IPR. In reality, it has been exceedingly rare for amendments to be allowed. Patent claims in an IPR may be amended only if a motion to amend is granted. The PTAB has required the patent owner to make a showing that the amended claims are patentable over not only the prior art relied on by the petitioner, but all prior art known to the Patent Owner. In denying almost all motions to amend, the PTAB has consistently held that the Patent Owner did not meet its burden of showing patentability.5

The Federal Circuit Court of Appeals had previously upheld the PTAB’s standard for motions to amend until this month. In an en banc decision in Aqua Products, Inc. v. Matal, 2017 WL 4399000 (Fed. Cir. Oct. 4, 2017) the Federal Circuit held that the PTAB has misconstrued the statute governing IPRs.  Specifically, the Federal Circuit concluded that the statute required that the petitioner has the burden to prove unpatentability, not only of the existing patent claims, but of any amended claims. This in turn means that Patent Owners may more freely amend the claims under review. This does not mean, however, that there are no constraints on the type of amendments that may be made. The rules governing IPRs require that amendments may not enlarge the scope of the claim being amended nor may it add new matter. Further, amendments must respond to a ground of unpatentability raised by the petitioner.

Even with these limitations on the type of amendments that can be made, there are clear benefits to an enhanced ability to amend.  Petitions for IPR are only granted if the Petitioner has shown that it is likely that at least one claim of the patent sought to be reviewed is more likely than not to be found invalid in view of the prior art. A patent owner may want to amend one or more claims by adding limitations not shown in the prior art so that the claims may be allowed as patentable. As another example, confronted with a broad construction of a claim term that makes unpatentability of the claim more likely, a patent owner may wish to amend the claim to achieve a narrower construction, which is more likely patentable. This is especially true if the narrowed claim scope still encompasses the allegedly infringing product.

In each of the above examples, the original claim will be lost. If the amended claim is held patentable, the patent owner will walk away from the IPR with narrowed rights, but at least some rights. Until now, it has typically been all or nothing.


Microsoft Corp. v. i4i Ltd. P’ship, 564 US 91 (2011).

35 U.S.C. § 316(e).

415 F.3d 1303 (Fed. Cir. 2005)

Cuozzo Speed  Techs, LLC v. Lee, 579 US ___, 136 s. Ct. 2131  (2016).

See PTAB Motion to Amend Study, available at https://www.uspto.gov/sites/default/files/documents/2016-04-30%20PTAB%20MTA%20study.pdf, finding that only 6 of 118 filed Motions to Amend in IPRs were granted (in whole and in part) as of April 30, 2016.