Obviousness-Type Double Patenting

Who Would Have Thought It Would Have Such a Profound Effect on the Pharmaceutical Industry?

Anthony M. Insogna, Julie M. Baher, and Colin A. Forestal

©2012. Published in Landslide, Vol. 5, No. 1, September/October 2012, by the American Bar Association. Reproduced with permission. All rights reserved. This information or any portion thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association or the copyright holder.

Whether litigating or prosecuting pharmaceutical patents, it has become increasingly clear that all patent practitioners must be cognizant of the recent developments in the law of obviousness-type patenting, and their potentially dramatic effects on the pharmaceutical industry. For prosecutors, no longer is it quite as simple to “expand the picket fence” and file multiple patent applications—related or unrelated—to cover various aspects of a client’s inventions. For litigators, the obviousness-type double patenting defense has taken on entirely new life, and can lead to a finding of invalidity or the necessity to terminally disclaim and cut short a patent with valuable term remaining. Depending on which side one represents, the application of obviousness-type double patenting can be either extremely beneficial or extremely damaging.

The Basics of Obviousness-Type Double Patenting

A brief overview is first presented of what obviousness-type double patenting is, where it came from, and how terminal disclaimers may be used to overcome a double patenting rejection issued by the United States Patent and Trademark Office (USPTO) or a challenge made by a defendant during litigation.

Development of the Law of Obviousness-Type Double Patenting

The Constitution entitles inventors to a limited monopoly in exchange for public disclosure of their invention.1 However, per 35 U.S.C. § 101, Congress has limited this monopoly to only one patent per invention. “The doctrine of double patenting is intended to prevent a patentee from obtaining a time-wise extension of [a] patent for the same invention or an obvious modification thereof.”2 Double patenting comes in two varieties: (1) “statutory” double patenting, which stems from § 101 and prohibits a later patent from covering the same invention, i.e., identical subject matter, as an earlier patent;3 and (2) “obviousness-type” double patenting, which is a judicially-created doctrine essentially preventing a later patent from covering a slight variation of an earlier patented invention.

The Court of Customs and Patent Appeals (CCPA), predecessor to the United States Court of Appeals for the Federal Circuit, restated the law of double patenting in an early case, In re Vogel:

The first question in the analysis is: Is the same invention being claimed twice? 35 U.S.C. § 101 prevents two patents from issuing on the same invention . . . .
If it is determined that the same invention is being claimed twice, 35 U.S.C. § 101 forbids the grant of the second patent, regardless of the presence of absence of a terminal disclaimer. If the same invention is not being claimed twice, a second question must be asked.
The second analysis question is: Does any claim in the application define merely an obvious variation of an invention disclosed and claimed in the patent? . . .
If the answer to the second question is no, there is no double patenting involved and no terminal disclaimer need be filed. If the answer is yes, a terminal disclaimer is required to prevent undue timewise extension of monopoly.4

In the late 1980s and early 1990s, the Federal Circuit reinforced that obviousness-type double patenting is “altogether a matter of what is claimed.”5 Significantly, in General Foods Corp. v. Studiengesellschaft Kohle mbH, the court emphasized that “[o]ur 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.”6 In In re Kaplan, it noted that treating the patent disclosure as though it were prior art has “repeatedly been held in our precedents to be impermissible.”7 The prohibition against consulting the specification during an obviousness-type double patenting analysis has never been absolute, however, and one is not precluded from any and all forays into the specification. This fact was illustrated by the court in In re Vogel, which determined that “in certain instances [the disclosure] may be used as a dictionary to learn the meaning of terms in a claim” and also may be used to assess whether a claim in an application merely defines an obvious variation of the patented claim.8 Today, the use of the specification and additional references in such rejections is becoming commonplace.

Usage of Terminal Disclaimers to Overcome Obviousness-Type Double Patenting

A terminal disclaimer is a statement filed by an owner of a patent, or application to be granted, that is used to disclaim or dedicate a portion of the entire term of all the claims in a patent.9 Terminal disclaimers are highly important, as they may be used to overcome an obviousness-type double patenting rejection in prosecution or during a challenge made in the course of litigation. But there are limitations on how and when this may be accomplished.

First, a terminal disclaimer can only be used where the conflicting application or patent is commonly owned with the application or patent at issue, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement.10

Regarding timing, a terminal disclaimer may be filed during prosecution or even after the challenged patent has issued. Indeed, the Federal Circuit has permitted patentees to file terminal disclaimers during litigation—even late in the proceeding—as a response to an obviousness-type double patenting invalidity challenge, and even after a finding that the challenged patent is invalid for obviousness-type double patenting.11 However, as established in Boehringer Ingelheim International GmbH v. Barr Laboratories, Inc., a terminal disclaimer must be filed before expiration of the earlier-issued patent and cannot be “retroactive.”12

One final twist in the story is that, according to Eli Lilly & Co. v. Barr Laboratories, Inc., “[a] patent owner cannot avoid double patenting by disclaiming the earlier patent.”13 Because the earlier patent cannot be statutorily disclaimed, it is even more crucial to be able to comply with the “how” and “when” of filing a terminal disclaimer in connection with the later patent.

It is against this backdrop that the recent evolution of obviousness-type double patenting will now be explored, specifically in the context of three “pitfalls” identified below.

The Compound/Method of Use Pitfall

Through a series of decisions beginning in 2003, the Federal Circuit has vastly expanded the reach of the doctrine of obviousness-type double patenting between compound and method of use claims.

First, in Geneva Pharmaceuticals, Inc. v. GlaxoSmithKline PLC, the Federal Circuit found claims in Geneva’s U.S. Patent No. 4,529,720 (’720 Patent), which were directed to a method of effecting beta-lactamase inhibition comprising administering clavulanic acid, to be invalid for obviousness-type double patenting over claims in an earlier, commonly owned patent that were directed to the compound potassium clavulanate.14 The specification of the earlier patent disclosed that the compound could be suitable for pharmaceutical use, and the district court held that inhibiting beta-lactamase is an inherent property of potassium clavulanate. The Federal Circuit, in reviewing the district court’s judgment of invalidity, examined the disclosure of the earlier claim, but did not consider the earlier claim in a vacuum. The court noted:

[C]laim 1 of the ’720 patent is drawn to a compound having a certain physical property. Standing alone, that claim does not adequately disclose the patentable bounds of the invention. Therefore, this court examines the specifications of both patents to ascertain any overlap in the claim scope for the double patenting comparison.15

The court found that a person of ordinary skill in the art reviewing the disclosure of the earlier patent would recognize a single use for potassium clavulanate, i.e., administration to patients to combat bacteria that produce beta-lactamase. In fact, the earlier patent disclosed no other use for potassium clavulanate, and the later ’720 Patent merely claimed that use as a method. Thus, because the earlier patent claimed a compound, and its specification disclosed a single utility of that compound, the later ’720 Patent claims directed to such utility were held to not be patentably distinct.16

A similar decision was reached in Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc. Specifically, Pfizer’s U.S. Patent No. 5,760,068 (’068 Patent) had claims directed to methods of administering a therapeutically effective amount of a composition comprising celecoxib, a COX-2 inhibitor which is the active ingredient in Celebrex®, to treat inflammation and inflammation-associated disorders, including arthritis, pain, and fever. Pfizer’s earlier U.S. Patent No. 5,563,165 (’165 Patent) had claims directed to compositions comprising celecoxib, and its specification also disclosed use of these compositions in treating inflammation and inflammation-associated disorders.17 This was a very common occurrence based upon years of typical prosecution strategy.18

During prosecution, Pfizer’s original application included claims directed to chemical compounds, methods of use, and compositions, including specific claims to celecoxib. The USPTO issued a restriction requirement, wherein Pfizer was required to select for prosecution the compound claims, the composition claims, or the method claims. Pfizer elected to prosecute generic compound claims, and then filed a series of continuation applications covering the nonelected subject matter, including a divisional application that ultimately issued as the ’165 Patent and a continuation-in-part application that ultimately issued as the ’068 Patent. The district court held that the asserted claims of the ’068 Patent were not invalid for obviousness-type double patenting in view of the earlier ’165 Patent based on application of the “safe harbor” of 35 U.S.C. § 121, which will be discussed below.19 The Federal Circuit disagreed that the “safe harbor” applied, and proceeded to analyze the double patenting issue substantively.20

The court relied upon Geneva’s holding that “a ‘claim to a method of using a composition is not patentably distinct from an earlier claim to the identical composition in a patent disclosing the identical use.’”21 The court found that the relevant claims of the two patents were not patentably distinct, because the claims at issue in the ’068 Patent merely recited methods of administering therapeutically-effective amounts of the compositions claimed in the ’165 Patent, and claimed a particular use described in the ’165 Patent of the compositions claimed therein. The court also made clear that “[t]here is nothing that prevents us from looking to the specification [of the ’165 patent] to determine the proper scope of the claims.”22

Unlike in Geneva, however, the specification of the earlier patent in Pfizer disclosed more than one use for the compositions claimed therein. Specifically, the specification of the ’165 Patent described the compositions’ use in treating both inflammation and inflammation-associated disorders, and enumerated nearly 50 different inflammation-associated disorders. Thus, the court seemingly took the holding in Geneva one step further.

Finally, in Sun Pharmaceutical Industries, Ltd. v. Eli Lilly & Co., a panel of the Federal Circuit relied upon the Geneva and Pfizer cases to invalidate Lilly’s U.S. Patent No. 5,464,826 (’826 Patent) claims based on obviousness-type double patenting.23 Lilly’s U.S. Patent No. 4,808,614 (’614 Patent) claimed gemcitabine, as well as a method of using gemcitabine for treating viral infections. The ’826 Patent-in-suit, on the other hand, claimed a method of using gemcitabine for treating cancer. The ’614 Patent was derived from a continuation-in-part application, and the specification of the original parent application did not disclose using gemcitabine to treat cancer. The continuation-in-part that resulted in the ’614 Patent added a brief description of gemcitabine’s anticancer utility to the specification.24 However, the ’614 Patent did not claim a method of using gemcitabine to treat cancer.

Sun sought approval to market a generic version of Lilly’s Gemzar®, and filed a declaratory judgment action against Lilly, alleging the ’826 Patent was invalid for obviousness-type double patenting over the earlier ’614 Patent. In finding the ’826 Patent invalid, the Federal Circuit essentially established a bright-line rule that a claim to a method of using a compound is invalid for obviousness-type double patenting over an earlier claim to that compound, so long as the earlier patent discloses anywhere in the specification the later-claimed method of use. Specifically, the court rejected Lilly’s attempt to distinguish Geneva and Pfizer as cases in which the specification of the earlier patent disclosed a single use for the claimed compound, which was an essential part of the patented invention, and thus necessary to patentability.25 The court disagreed that Pfizer involved a single disclosed utility, and noted: “Pfizer never implies that its reasoning depends in any way on the number of uses disclosed in the specification of the earlier patent.”26 Lilly also argued that Geneva and Pfizer do not apply to the ’826 Patent claims reciting a method of using gemcitabine for cancer treatment because, though the specification of the ’614 Patent disclosed both antiviral and anticancer uses of gemcitabine, the antiviral use provided the essential utility necessary to the patentability of the ’614 Patent’s claims. The court rejected Lilly’s “single essential utility test” as unworkable.27

Ultimately, the court found that:

the holding of Geneva and Pfizer, that a “claim to a method of using a composition is not patentably distinct from an earlier claim to the identical composition in a patent disclosing the identical use,” extends to any and all such uses disclosed in the specification of the earlier patent.28

The court also confirmed that, where a patent claims a compound, a court performing an obviousness-type double patenting analysis should examine the specification to ascertain the coverage of the claim.29 Thus, in light of the earlier ’614 Patent’s—albeit limited—description of gemcitabine’s use in treating cancer, the asserted claims of the later ’826 Patent, which recited a method of using gemcitabine to treat cancer, were found to be invalid for obviousness-type double patenting over the ’614 Patent’s claim to gemcitabine.

Lilly petitioned for rehearing en banc, which was denied in late 2010.30 Lilly then filed a petition for certiorari in the United States Supreme Court, which was denied on May 16, 2011.31 Thus, we are left with the panel’s decision, which many have criticized as overexpanding and distorting the obviousness-type double patenting doctrine. Most notably, Judge Newman’s dissent in the denial of rehearing emphasized that the law of double patenting, as established by General Foods and In re Vogel, is contrary to the panel’s holding, condemned the panel for being “misdirected by an overly-broad statement” in Geneva, and urged that there is no “shock” to “one’s sense of justice” where a nonobvious, later-claimed use is the result of a later discovery.32

For good or for bad, Lilly provides certain incentives and necessitates careful planning for pharmaceutical companies looking to file composition of matter and method of use cases. First, a drug company may now feel compelled to disclose as few uses of a new compound as possible to satisfy the utility requirement in an original application, and then only disclose and claim new uses in later applications as they arise. Lilly may, similarly, encourage pharmaceutical companies to prioritize follow-on research only on uses of the compound that were not disclosed in the original application. Furthermore, if a drug company desires separate patents on a compound and its methods of use, it should consider applications with the same effective filing date. This way, if a terminal disclaimer must be filed, it will not have a drastic effect, barring any major differences in patent term adjustment (PTA) awarded to the various applications.33 Alternatively, the company may try to claim both the compound and all of its disclosed methods of use in one application, in order to provoke the USPTO to issue a restriction requirement, and then elect to prosecute the compound and various methods of use in separate divisional applications that would be protected from one another under 35 U.S.C. § 121. In any event, Lilly should motivate every patent prosecutor to evaluate his or her clients’ pharmaceutical portfolios with extreme care and caution from the outset.

The Composition/Compound Pitfall

In In re Metoprolol Succinate Patent Litigation, the Federal Circuit held that a claim in AstraZeneca’s later patent—directed to the compound metoprolol succinate—was invalid for obviousness-type double patenting because it was an obvious variation of a claim in an earlier patent—directed to a pharmaceutical composition containing that very compound and other elements.34 The court found that “the omission of the known elements from the composition in this case is ‘the product not of innovation but of ordinary skill and common sense.’”35 Importantly, the court found that the composition of the earlier patent claim included the compound of the later claim in its entirety. Specifically, the earlier patent not only disclosed but also claimed a composition comprised in part of metoprolol succinate. In view of In re Metoprolol, patent prosecutors now have an incentive to ensure that compound claims issue before pharmaceutical composition claims, assuming they are patentably distinct.

The Continuing Application Pitfall

One way to overcome an obviousness-type double patenting challenge without filing a terminal disclaimer is to take advantage, when applicable, of the “safe harbor” of 35 U.S.C. § 121. The pitfalls described above highlight the importance of being able to benefit from this provision. Section 121 provides, in relevant part:

A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application.

The rationale is that issuance of a restriction requirement from the USPTO is a statement that the claims being restricted cover two or more independent and distinct inventions. Note, however, that the “safe harbor” will not apply in every case in which a divisional application has been filed, or even in every case in which the USPTO has imposed a restriction requirement. The waters of the “safe harbor” have proven muddier to navigate than one would initially suspect.

The “Safe Harbor” Does Not Protect Voluntarily-Filed Divisional Applications

The Federal Circuit has made clear that § 121 requires claims of a divisional application to have been formally entered, restricted, and removed from an earlier application in order to benefit from the “safe harbor.” In other words, voluntary divisional applications are not protected. This was illustrated in Geneva Pharmaceuticals, Inc. v. GlaxoSmithKline PLC.36

The relevant patents in Geneva were an earlier-issued patent (the ’720 Patent), which claimed methods of use of clavulanic acid, and a series of later-issued patents (the 2000/01 patents) that contained composition claims.37 The court was asked to consider whether § 121 shielded the 2000/01 patents from double patenting rejections over the earlier ’720 Patent because the earlier patent resulted from a divisional application of a common parent. However, the common parent did not contain the method of use claims that later appeared in the ’720 Patent, and the examiner had not issued a formal restriction requirement relating to the claims at issue during prosecution of the common parent.

The court, analyzing the language of § 121, concluded that an earlier application must contain formally entered claims that are restricted and removed, and that the claims to the second invention must reappear in a separate divisional application after the restriction.38 Because the method of use claims had never been entered in the common parent application, the court reasoned that they could not have been subject to a restriction requirement. Moreover, the only formal restriction requirements that were issued during prosecution of the common parent application actually grouped the composition claims together with corresponding method of use claims, indicating that the USPTO did not consider them to be patentably distinct.39 Thus, the court refused to apply § 121’s “safe harbor.”

Only Divisional Applications Are Eligible for Protection under the “Safe Harbor”

Where the “safe harbor” is concerned, a divisional by any other name would not smell as sweet. In Pfizer, the Federal Circuit concluded that § 121 is limited to divisional applications.40 Relying upon the explicit reference to “divisional applications” in § 121 and its legislative history, the court refused to apply the “safe harbor” to the claims of Pfizer’s continuation-in-part patent, despite the fact that it was filed in response to a restriction requirement. Subsequently, in Amgen Inc. v. F. Hoffman-La Roche Ltd., the court concluded that, because the patents at issue were filed as continuation applications, they did not receive the benefit of § 121.41 This was, again, despite the fact that such continuations were filed in response to a restriction requirement, and could have been filed as divisionals. Thus, in order to be able to take advantage of the “safe harbor” later on, patent prosecutors should be careful to file true “divisional” applications when pursuing claims that have been carved out from an earlier application as a result of a restriction requirement.

Intervening Continuation or Divisional Applications May Be Eligible for Protection under the “Safe Harbor”

While the Federal Circuit in Amgen declined to apply § 121 to the continuation applications at issue therein, it did acknowledge that the “safe harbor” can apply to certain continuation applications.42 Specifically, the court found that a patent need not have issued directly from a divisional application to receive § 121 protection, and that “intervening continuation applications do not render a patent ineligible for § 121 protection so long as they descended from a divisional application filed as a result of a restriction requirement.”43 Along those same lines, the Federal Circuit also recently confirmed in Boehringer that the “safe harbor” can apply to a divisional of a divisional application in which a restriction requirement was entered.44

Concluding Thoughts

This article merely scratches the surface of the obviousness-type double patenting pitfalls that can trap the unwary patent prosecutor and add new complexity to pharmaceutical litigation. Awareness of recent developments in the law is more crucial than ever to effective life-cycle management of pharmaceutical patent portfolios, as well as to anticipating, defending against, and proffering obviousness-type double patenting challenges during litigation. It remains to be seen whether the Supreme Court will, as it has so often recently, step in to clarify or reshape the doctrine.


1. U.S. Const. art. I, § 8.

2. In re Basell Poliolefine Italia S.P.A., 547 F.3d 1371, 1375 (Fed. Cir. 2008) (alteration in original) (internal quotation marks omitted).

3. The nomenclature “earlier patent” or “first patent” in an obviousness-type double patenting analysis refers to the earlier-issued patent, whereas “later patent” or “second patent” refers to the later-issued patent.

4. 422 F.2d 438, 441–42 (C.C.P.A. 1970).

5. Gen. Foods Corp. v. Studiengesellschaft Kohle mbH, 972 F.2d 1272, 1277 (Fed. Cir. 1992).

6. Id. at 1281.

7. 789 F.2d 1574, 1580 (Fed. Cir. 1986).

8. 422 F.2d at 441–42.

9. See, e.g., U.S. Patent & Trademark Office, Manual of Patent Examining Procedure (MPEP) § 804.02(V) (8th ed. Rev. 8, Jul. 2010).

10. See, e.g., 37 C.F.R. § 1.321(c)(3), (d)(3).

11. See, e.g., Perricone v. Medicis Pharm. Corp., 432 F.3d 1368, 1375 (Fed. Cir. 2005); Boehringer Ingelheim Int’l GmbH v. Barr Labs., Inc., 592 F.3d 1340, 1347 (Fed. Cir. 2010) (citing Perricone, 432 F.3d at 1375).

12. 592 F.3d at 1347–48.

13. 251 F.3d 955, 967 n.5 (Fed. Cir. 2001). Note that this finding does not appear to be based on any real precedent or statutory purpose.

14. 349 F.3d 1373, 1384–86 (Fed. Cir. 2003).

15. Id. at 1385.

16. Id. at 1385–86.

17. See Pfizer, Inc. v. Teva Pharm. USA, Inc., 518 F.3d 1353, 1356, 1363 (Fed. Cir. 2008).

18. Indeed, composition claims confer protection independent of a specific use, whereas method claims are limited to the use(s) recited.

19. Pfizer, 518 F.3d at 1358–59.

20. Id. at 1362.

21. Id. at 1363 (quoting Geneva, 349 F.3d at 1385–86).

22. Id. at 1363 n.8 (citing Geneva, 349 F.3d at 1386).

23. Sun Pharm. Indus., Ltd. v. Eli Lilly & Co., 611 F.3d 1381 (Fed. Cir. 2010).

24. Id. at 1383.

25. Id. at 1385–86.

26. Id. at 1386 (citing Pfizer, 518 F.3d at 1363).

27. Id. at 1387 n.3.

28. Id. at 1387 (citation omitted).

29. Id. at 1388.

30. Sun Pharm. Indus., Ltd. v. Eli Lilly & Co., 625 F.3d 719 (Fed. Cir. 2010).

31. Eli Lilly & Co. v. Sun Pharm. Indus., Ltd., 131 S. Ct. 2445 (2011).

32. Sun Pharm., 625 F.3d at 721–23 (Newman, J., dissenting).

33. This strategy, of course, may limit the ultimate patent term enjoyed by a product.

34. 494 F.3d 1011 (Fed. Cir. 2007).

35. Id. at 1017 n.2 (quoting KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007)).

36. 349 F.3d 1373, 1379–80 (Fed. Cir. 2003).

37. See id. at 1376–77.

38. Id. at 1379.

39. Id. at 1379–80.

40. Pfizer, Inc. v. Teva Pharm. USA, Inc., 518 F.3d 1353, 1362 (Fed. Cir. 2008).

41. 580 F.3d 1340, 1352 (Fed. Cir. 2009).

42. Id. at 1353–54 (citations omitted); see also St. Jude Med., Inc. v. Access Closure, Inc., No. 08-CV-4101, 2011 WL 5374424, at *4 (W.D. Ark. Nov. 8, 2011).

43. Amgen, 580 F.3d at 1354.

44. Boehringer Ingelheim Int’l GmbH v. Barr Labs., Inc., 592 F.3d 1340, 1351–52 (Fed. Cir. 2010).