Abstract
O
The contours of OTPD are grounded in public policy—the doctrine was created by the courts primarily as a means to address perceived loopholes in the patent statute that could be exploited by an inventor to obtain a second patent on an obvious variation of subject matter claimed in an earlier patent, resulting in an unwarranted de facto extension of the patent term beyond the statutorily prescribed period.4 This was a very real concern in an era in which a patent enjoyed a term of 17 years from the date of issuance, prior to implementation of the General Agreement on Tariffs and Trade (GATT) in 1995. As recently noted by Chief Judge Rader, under the pre-GATT regime, “[a] patentee could file successive continuations and obtain additional patent terms for obvious modifications of its earlier claims where its earlier patents and applications did not qualify as prior art, and perhaps do so ad infinitum.”5
GATT has generally limited the term of patents to 20 years from the effective filing date, and one might have thought that OTDP would fade in significance as patents filed prior to the implementation of GATT expired over time. In fact, however, the doctrine remains highly relevant for patents filed post-GATT, for two primary reasons. The first is that there has long been an important ancillary policy justification for the doctrine, which is to prevent multiple infringement suits brought by different assignees asserting patents claiming essentially the same invention, and this concern was not directly impacted by GATT's change to the patent term. The second, perhaps more notable, reason is that courts have continued to expand the doctrine to encompass situations that can occur even under the post-GATT patent term regime.
This article considers three aspects of OTDP that have been expanded by recent Federal Circuit decisions: (1) greater use of the disclosure (as opposed to the claims) of a first patent to bar claims in a second patent; (2) application of the doctrine under circumstances wherein there is a common inventor but no common inventive entity and no common ownership; and (3) use of a later-issued, but earlier-expiring, patent to invalidate an earlier-issued, but later-expiring, patent in spite of the fact that the patents are subject to a requirement of common ownership.
The first expansion occurred incrementally in a series of three Federal Circuit decisions decided between 2003 and 2010: Geneva Pharmaceuticals v. GlaxoSmithKline PLC,6 Pfizer v. Teva Pharmaceuticals USA,7 and Sun Pharmaceutical Industries v. Eli Lilly & Co.8 Prior to the court's 2003 decision in Geneva, it was generally thought to be black-letter law that OTDP is concerned solely with a comparison between the claims of two patents. For example, Chisum on Patents taught that “[d]ouble patenting is concerned with attempts to claim the same or related subject matter twice. Thus, the standard for comparison for the second patent is what was claimed in the first patent, not what was disclosed in the specification of the first patent.”9 In 1992, the Federal Circuit stated unambiguously in General Foods v. Studiengesellschaft Kohle that its “precedent makes clear that the disclosure of a patent cited in support of a double patenting rejection cannot be used as though it were prior art, even where the disclosure is found in the claims.”10
In Geneva, the Federal Circuit opened the door to using the disclosure of a first patent under the auspices of OTDP when it invalidated a second patent claiming a method of using a chemical compound as a pharmaceutical, based on the disclosure of this method of use in an earlier co-owned patent.11 Although Geneva seemed to contradict the traditional prohibition against looking beyond the claims in assessing OTPD, the holding might arguably be rationalized by the specific facts of the case. The earlier patent disclosed only a single use for the chemical compound, and for that reason, the Federal Circuit presumed that this method of use was necessary to establish the patentable utility of the compound.12 Geneva cited a 1942 CCPA decision for the proposition that, because the earlier patent depended critically on the disclosure of the single utility, that utility could not constitute a separate invention, but rather is “an essential part of a single invention.”13
Two years later, in Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc., another Federal Circuit panel cited to Geneva when it invalidated a second patent claiming a pharmaceutical method of using a compound, again based on disclosure of that method in an earlier patent claiming the chemical compound as a composition of matter.14 The facts in Pfizer differed substantially from those of Geneva, in that the earlier patent specification disclosed multiple uses of the compound.15 Thus, the Geneva panel's justification for looking beyond the claims of the first patent would not appear to be present in Pfizer. That is, at least some of the claims in the second patent invalidated for OTDP claimed only a subset of the methods disclosed in the first patent and therefore were not necessary to establish the patentable utility of the chemical compound. In effect, Pfizer further widened the door opened by Geneva in allowing the court to look beyond the claims of the first patent in the OTDP inquiry.
Against this backdrop, in 2010, the Federal Circuit took up the issue of OTDP in Sun Pharmaceutical Industries, Ltd. v. Eli Lilly & Co.16 In Sun Pharmaceutical, the court treated Geneva/Pfizer as having established a bright-line rule that any method of using a pharmaceutical compound that is claimed in a second patent is invalid for OTDP if that method of use was disclosed in an earlier patent claiming the compound as a composition of matter, regardless of the circumstances under which that disclosure entered the specification.17 In particular, the court held that that the disclosure of anticancer activity in a composition of matter patent, which was only introduced after the initial filing date as a result of an amendment to a continuation-in-part (CIP) application, and which was not claimed in that patent, rendered a second patent claiming the anticancer activity invalid as a matter of law.18 In a dissent to the Federal Circuit's decision to deny Lilly's petition for rehearing en banc, four judges (including Chief Judge Rader, who wrote Geneva) argued that Sun Pharmaceuticals had extended Geneva in a manner that is contrary to the law of double patenting and that “does not further the policy of obviousness-type double patenting.”19
Significantly, the additional disclosure that Lilly added to the CIP application and which resulted in the invalidation of their anticancer method patent seems to have been entirely gratuitous.20 Lilly argued that they added the disclosure of anticancer activity to the originally filed composition of matter application out of an abundance of caution, in their attempt to comply with the best mode requirement, but in retrospect, it appears that they did not need to add the disclosure.21 Unfortunately, the decision to file the CIP disclosing anticancer activity was made prior to the Federal Circuit's decision clarifying the extent to which an inventor is required to update the disclosure of best mode in a pending patent application.22 Sun Pharmaceutical illustrates how judge-made expansion of OTDP can create patent prosecution pitfalls that come to light only years after the ultimately disastrous prosecution decision has been made.
The second expansion to be considered occurred in 2013, when, for the first time, the Federal Circuit invoked OTDP to invalidate patent claims in a case wherein there was neither a common inventive entity nor common ownership.23 In In re Hubbell, the panel majority found the existence of a common inventor to be sufficient. This had already been the position of the U.S. Patent and Trademark Office (PTO), as set forth in the Manual of Patent Examining Procedure (MPEP),24 but prior to Hubbell, the Federal Circuit had explicitly treated this issue as an open question.25 The holding in Hubbell could prove particularly problematic in cases where an inventor moves to a different employer while continuing a research program initiated with a previous employer—university researchers would be a prime example.
In particular, Hubbell involved a University researcher who moved from the California Institute of Technology (Caltech) to a Swiss university (ETHZ). Caltech filed an application directed toward certain fusion proteins useful in tissue repair and regeneration, which were purportedly invented by Hubbell and three co-inventors.26 The application was pursued with something less than a sense of urgency, including a fateful decision to forgo the issuance of claims allowed in 2003 in order to pursue somewhat broader claims in a continuation application.27 As a consequence, a patent naming a different inventive entity (Hubbell and a different set of co-inventors) and assigned to ETHZ issued prior to the issuance of Caltech's patent application.28 The panel majority upheld the PTO's decision that the earlier-issued ETHZ patent rendered Caltech's claims invalid for OTDP, rejecting Caltech's argument that the doctrine is not applicable in the absence of a common inventive entity or common ownership.29 The majority also rejected Caltech's request for permission to file a terminal disclaimer as a matter of equity.30
Writing in dissent, Judge Newman argued that the Hubbell majority had erred in expanding OTDP to encompass situations in which the application and patent are of separate ownership and have separate inventive entities.31 According to Judge Newman, “[i]n such situation the appropriate examination path is on the merits of the invention, or through the interference or derivation procedures, or other standard protocol as may apply in the particular situation.”32 She went on to fault the majority for engaging in flawed circular logic, explaining:
If there indeed is obviousness-type double patenting, then a terminal disclaimer is necessarily available. However, the court rules that a terminal disclaimer is not available because there is not common ownership. Yet if there is not common ownership or common inventorship, there cannot be double patenting.33
The third expansion occurred in Gilead Sciences v. Natco Pharma, decided on April 22, 2014, when a divided panel of the Federal Circuit held for the first time that a later-issued, but earlier-expiring, patent can invalidate a first-issued, but later-expiring, patent under OTDP—even when the patents are subject to a requirement of common ownership.34 This scenario was unlikely under the pre-GATT patent term regime, whereby the date of patent expiration is keyed to the date of issuance. But with the move to a patent term based on the effective filing date, it became possible for a later-issued patent to expire prior to an earlier-issued patent claiming priority to a later effective filing date, and that is what occurred in Gilead Sciences.
From the perspective of the patent owner, the outcome seems harsh. In 1998, Gilead received a first patent with an expiration date of December 27, 2016 directed toward its anti-influenza drug marketed as Tamiflu.35 In 2013, would-be generic competitor Natco conditionally stipulated to infringement of two claims of the first patent.36 However, in 2014, the Federal Circuit ruled that a second patent issued to Gilead in 1999 and which expires February 27, 2015 could render the first patent invalid for OTDP.37 In other words, issuance of the second patent in 1999 could result in a 20-month reduction in the term of the first patent.
Writing in dissent, Chief Judge Rader characterized the Gilead Sciences expansion of OTDP as unwarranted and argued that the policy concerns underlying the doctrine do not justify the majority's decision.38 He opined that courts should be particularly reluctant to create or expand judge-made exceptions to the rights granted by the patent statute, and expressed concern as to how Gilead Sciences would interact with the new “first-inventor-to-file” provisions of the AIA, predicting that the holding could have unforeseen negative consequences as prospective patentees face greater pressure to file their patent applications early.39
In my view, Chief Judge Rader's observations are well taken, and generally apply to other recent Federal Circuit decisions expanding the scope of OTDP. Some of the judges on the Federal Circuit appear to have lost track of the policy concerns underpinning this judge-made doctrine, and have extended it to apply in scenarios where the policy concerns are not present, such as, for example, because of changes in the patent statute. Perhaps explicit codification of OTDP by Congressional action would be a good thing, so long as it is accomplished in a manner that reflects the statutory changes that have occurred in the decades since the courts initially created the doctrine. But for the foreseeable future, OTDP will continue to create patent prosecution pitfalls for those involved in the management and prosecution of biotechnology patent portfolios.