The courts have long stated that one goal of patent law is to provide certainty to both inventors and the public regarding the law that is applied in determining the metes and bounds of a patent claim. Patent claims that are ambiguous and vague in scope leave the public in doubt as to what is protected by the patent and is considered to exert a chilling effect on further innovation. What is one sure fire way to destroy certainty? Having two differing legal standards applied to claim interpretation seem to fit the bill. This is exactly the situation encountered when patent claims are evaluated for indefiniteness under 35 USC §112(b) by courts in the context of patent litigation and the Patent Trial and Appeal Board (PTAB) in pre- and post-issuance proceedings.

Lower Threshold for Indefiniteness Confirmed by PTAB in Ex Parte McAward

Differing Standards for Indefiniteness

District courts and the CAFC apply the now familiar standard for claim indefiniteness under Nautilus as set forth by the Supreme Court, which states a claim is invalid as indefinite if the claim “read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.” Nautilus replaced the prior test for indefiniteness which required a claim to be “insolubly ambiguous.” The PTAB however has stated that it is not bound by the USSC’s decision in Nautilus. The PTAB standards for determining indefiniteness are whether a claim “contains words or phrases whose meaning is unclear” as set forth in In re Packard or “when a claim is amenable to two or more plausible constructions” as discussed in Ex Parte Miyazaki.

The PTAB explained in Ex Parte Miyazaki that in pre-issuance proceedings the board is justified in using a lower threshold “because the applicant has an opportunity and a duty to amend the claims during prosecution to more clearly and precisely define the metes and bounds of the claimed invention and to more clearly and precisely put the public on notice of the scope of the patent.”

The same standard has been applied in post-grant proceedings in Google, Inc. v. SimpleAir, Inc., where the board stated the basis for applying the lower threshold for indefiniteness in pre-issuance proceedings “stems from two factors: (1) the broadest reasonable interpretation claim construction standard; and (2) the lack of a presumption of validity before the Office.” As the board found the same two factors apply to post-grant proceedings, the lower standard for indefiniteness was proper. This approach was also confirmed in Tinnus Enterprises, LLV v. Telebrands Enterprises, where the board stated “We do not understand Nautilus, however, to mandate the Board’s approach to indefiniteness in patent examination or reexamination matters or in AIA proceedings, in which the claims are interpreted under the broadest reasonable interpretation standard, and an opportunity to amend the claims is afforded.”

As we discussed previously, these differing standards can result in different outcomes in the CAFC and the PTAB (Tinnus Enterprises, LLV v. Telebrands Enterprises).

Ex Parte McAward Confirms PTAB Approach in Pre-Issuance Proceedings

The PTAB issued a precedential decision, a rare occurrence, in Ex parte McAward on August 25, 2017. The decision serves as clear confirmation that the PTAB will continue to use the lower threshold for indefiniteness as set forth in In re Packard and Ex Parte Miyazaki in pre-issuance proceedings. However, the board’s decision expressly limits the holding to pre-issuance proceedings, leaving some doubt as to the continued application of the lower standard to post-grant proceedings. Specifically, the board stated “We do not address, in this decision, the approach to indefiniteness that the Office follows in post-grant trial proceedings under the America Invents Act.” Therefore, until a precedential decision from the board addresses the application of the lower standard in post-grant proceedings, the proper standard for the evaluation of claim indefiniteness for post-grant proceedings is still in some doubt.

While the same factors relied on by the PTAB in applying the lower threshold are arguably present in post-issuance proceedings, the issue of how freely claim amendments are entered in post-grant proceedings has recently been called into question. In In re Aqua Products (CAFC, 2015-1177), the CAFC granted en banc review in December 2016 to determine if the board’s approach to claim amendments during post-grant proceedings is too limiting. While a decision still has not been handed down, if it is found that patent owners do not have the opportunity to freely amend their claims (as required by the logic of Google, Inc. v. SimpleAir, Inc. and Tinnus Enterprises, LLV v. Telebrands Enterprises) the PTAB’s logic in applying the lower standard is called into question, arguing that the proper standard for evaluating claim indefiniteness in post-grant proceedings should in fact be the Nautilus standard as applied by the district courts and the CAFC.

Points to Consider

For the present, it should be expected that the PTAB will continue with its current approach to evaluating claim indefiniteness in both pre- and post-issuance proceedings. As a result, it will remain the case that patent claims will be easier to invalidate on indefiniteness grounds in front of the board as compared to district court. While the situation may change with respect to post-grant proceedings, it is unlikely to change with respect to pre-issuance proceedings.

Therefore, those wishing to challenge claims on the ground of indefiniteness should carefully consider their options and consider taking advantage of the lower threshold available in front of the board. Likewise, patent applicants and owners should evaluate their cases for vulnerability under the PTAB’s current standards.

Vitamin B12In the patent world, claim scope depends on the meaning given to the individual words in the claim. If the meaning of a word in the claim is not clear, the claim may be attacked as invalid under the indefiniteness standard. Is a claim indefinite if the claim contains a term that is used by the patentee to refer to a specific compound in one part of the specification and to a broader class of related compounds in another part of the specification? If the claim contains a term that is admitted to have different meanings depending on the context in which the term is used? According to a recent ruling by the Federal Circuit, the answer to both questions is no.

35 U.S.C. § 112, ¶ 2, requires that a patent specification “conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.” Under the Supreme Court’s Nautilus ruling, a claim is invalid for indefiniteness “if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”

In Eli Lilly and Company v. Teva Parenteral Medicines, Inc., the issue of indefiniteness turned on the interpretation of the claim term “vitamin B12.” In this case, it was undisputed by the parties that the term “vitamin B12” as used in the specification can refer to either cyanocobalamin (a synthetic form of vitamin B12) specifically or, more broadly, to a class of compounds including pharmaceutical derivatives of cyanocobalamin. The patent defined vitamin B12 to mean “vitamin B12 and its pharmaceutical derivatives,” and that “[p]referably the term refers to vitamin B12, cobalamin, and chlorocobalamin. The parties also agreed that the term “vitamin B12” was used both ways in the specification.

Given these facts, one might think the claims were indefinite under the Nautilus standard. However, the CAFC determined that the claims were not indefinite in the context of the claims (which required administration to a patient), as one of ordinary skill in the art would understand that “vitamin B12” referred specifically to cyanocobalamin in the realm of medical treatment, thereby providing “reasonable certainty” as required under Nautilus.

Teva argued that because the claim term was used both ways in the specification, it was impossible to tell which meaning to use to interpret the scope of the claim with “reasonable certainty.” Lilly countered that the entire claim had to be considered in the indefiniteness inquiry and that since the claim specified administering “a vitamin B12 supplement to a patient,” one of ordinary skill in the art would know that the term referred to cyanocobalamin (which is the form used for human administration). Lilly supported this argument with expert testimony (which was not refuted, and in some ways confirmed, by Teva’s expert).

Understandings that lie outside the patent documents about the meaning of terms to one of skill in the art or the science or state of the knowledge of one of skill in the art are factual issues.

Importantly, the CAFC placed significant weight on the District Court’s use of the expert testimony on the issue and concluded that it found no clear error in the District Court’s conclusion that “vitamin” B12, when used to refer to vitamin B12 supplementation in a medical context, refers to cyanocobalamin.” The court distinguished Teva v. Sandoz on the grounds that the claim term at issue in that case did “not have a plain meaning to one of skill in the art that could be determined from context,” noting the expert admitted that the claim term had “no default meaning” (in contrast to the facts in the present case). In Teva v. Sandoz, the CAFC gave deference to the District Court’s subsidiary factual findings under the clear error standard set forth by the Supreme Court, but reviewed the application of the subsidiary factual findings as applied to the ultimate legal determination of indefiniteness de novo (without deference to the District Court). Because the expert testimony failed to provide reasonable certainty as to the meaning of the claim term, the CAFC found the claims indefinite, reversing the District Court.

The court also considered claim differentiation as supporting a clear meaning for “vitamin B12.”  Claim 1 listed both “vitamin B12” and cyanocobalamin (the asserted definition of “vitamin B12”) in claim 1 as suitable agents for use in the method (along with several other vitamin B12 derivatives). Claim 2 limited the agent to “vitamin B12” alone. The CAFC reasoned that since claim 2 specifically referred to “vitamin B12” alone, reading vitamin B12 as referring to a class of compounds would make claim 2 the same scope as claim 1. The court dismissed claim redundancy considerations, based on part on the prosecution history, having no issue with the claim 1 reciting cyanocobalamin twice in the claim.

This case illustrates the importance of expert testimony when fighting an indefiniteness challenge. It is critical that when expert testimony is presented regarding the meaning of a claim term, the testimony address the meaning of the term in the context of the claims to provide the public with reasonable certainty as to the meaning of the claim term in the context of the claims. If successful, the CAFC will have less flexibility in reversing factual determinations made by a District Court based on expert testimony.

Prosecution Disclaimer Has No TeethStatements made by patent practitioners to the patent office during patent prosecution can come back to bite you in related applications. Prosecution disclaimer allows a court to limit the literal scope of the claims in an infringement action. For prosecution disclaimer to attach, the accused infringer bears a heavy burden in asserting it: “the disavowal must be both clear and unmistakable.”

The patents at issue in MIT v. Shire cover methods for growing organs in vivo as an alternative to organ transplantation. Prior art methods for making thin organs such as skin were not useful for making thicker organs because cells at the center of the developing organ tended to die due to decreased diffusion of oxygen and nutrients to those cells. MIT scientists developed a “biodegradable, synthetic matrix that provides[s] support for cell growth applicable to tissue engineering for vascularized organs,” the subject of U.S. Patents 5,770,193 and 5,759,830.

MIT sued Shire for patent infringement, alleging that Shire’s Dermagraft® scaffold infringed the ‘193 and ‘830 patents. Shire asserted the doctrine of prosecution disclaimer as to three terms, but the opinion focused primarily on “vascularized organ tissue.” If vascularized organ tissue was construed to include skin, then Shire could be liable for infringement. It was undisputed that the ordinary meaning of vascularized organ tissue included skin and the ‘193 and ‘830 disclosures support that. However, Shire asserted that under the doctrine of prosecution disclaimer, vascularized organ tissue should be construed to exclude skin.

During the prosecution of the parent application 06/933,018, MIT attempted to overcome a prior art rejection by arguing that the prior art was limited to use for skin and could not be used for other organ equivalents. The examiner maintained the rejection over several office actions, eventually forcing MIT to limit the claims in the parent application to “scaffolds for growing ‘non-skin organ cells,’” that the examiner rejected as constituting new matter. MIT abandoned the ‘018 application and continued to prosecute the related ‘193 and ‘830 applications. Both included the same non-skin limitation. MIT eventually replaced the non-skin limitation with a limitation directed to the thickness of the claimed cell mass, which earned MIT another new matter rejection under § 112. In the end, MIT removed the thickness limitation and added the limitation “to produce functionalized organ tissue in vivo.”

Shire offers several statements made by MIT as evidence of prosecution disclaimer. The opinion discusses each in turn, but the most unambiguous statements were related to the “non-skin” claim limitation and the inventor’s declaration.

Shire points to the non-skin claim amendment as evidence of disclaimer, but the court found that this amendment did not overcome the presumption that vascularized organ tissue had an ordinary and customary meaning. Although the claim amendment clearly disavowed claim scope that would include skin, the court found that because the amendment was made in connection with different claims—the claims at the time did not recite vascularized organ tissue— then disclaimer did not attach.

Shire also pointed to a declaration, where the inventor stated that prior art methods were “limited to a very thin layer of cells” and that “the claimed method is not a method for making very thin structures.” The court was not persuaded that these statements constituted disclaimer because the statements were offered in support of the thickness limitation. The thickness limitation does not recite vascularized organ tissue, so disclaimer did not attach.

It is a rarity to prevail on a prosecution disclaimer argument in the courts. Practically speaking, the “clear and unmistakable” disavowal means that the statements by the patentee were made to overcome an examiner’s rejection and the PTO was persuaded to allow the claims. If it’s a losing argument—the examiner maintains the rejection or issues a new rejection in response—then there is no harm, no foul. Most importantly, the statements must be made in connection with the exact disputed claim terms for disclaimer to attach.