The Uruguay Round Agreements Act (URAA), Pub. L. 103-465, 108 Stat. 4809 (effective June 8, 1995), installed a twenty-year U.S. patent term from the earliest-claimed priority date, modifying the previous seventeen-year term calculated from the date of patent issuance.1  That change eliminated a perceived abuse—sometimes called "submarine patenting" or "evergreening"—wherein the use of continuing applications allowed claiming of previously disclosed features many, many years later, since patent expiration was calculated from the date of issuance.  In that former context, the prohibition against obviousness-type double patenting (OTDP) was a check ensuring that patentees could not obtain more than one patent based on merely unpatentable variations, effectively extending the monopoly on the same basic invention.   

When OTDP, also known as "non-statutory double patenting," was raised by AbbVie Inc. as a defense in an infringement suit brought by The Mathilda and Terence Kennedy Institute of Rheumatology Trust ("Kennedy"), the policy justification for the doctrine post-URAA was questioned.2  Kennedy argued that the rationale for the rule no longer exists and that the doctrine should be discarded.  The Federal Circuit, however, reaffirmed in its unanimous opinion that compelling reasons militate in favor of OTDP today:

It is designed to prevent an inventor from securing a second, later expiring patent for the same invention.  That problem still exists. . . .  [W]here, as here, the applicant chooses to file separate applications for overlapping subject matter and to claim different priority dates for the applications, the separate patents will have different expiration dates since the patent term is measured from the claimed priority date.3

In AbbVie, both patents at issue were directed towards methods of treating rheumatoid arthritis by co-administering two drugs—a disease-modifying antirheumatic drug (methotrexate) and an antibody (anti-TNF antibodies).  Kennedy sought and secured two patents on this combination therapy: it claimed the priority date of October 8, 1992 (the filing date of an earlier application), for U.S. Patent No. 6,270,766 ("the '766 patent"), and a later priority date, August 1, 1996 (the filing date of the '766 patent), for U.S. Patent No. 7,846,442 ("the '442 patent"), "so that the '422 patent would expire after the '766 patent."4  This timing made for a six-year difference in patent term.  "When such situations arise," explained the court, "the doctrine of obviousness-type double patenting ensures that a particular invention (and obvious variants thereof) does not receive an undue patent term extension."5  The Federal Circuit thus made explicit at least one post-URAA application for OTDP: "[T]he doctrine of obviousness-type double patenting continues to apply where two patents that claim the same invention have different expiration dates."6 

In analyzing whether the claimed matter was patentably distinct, the Federal Circuit affirmed the district court's finding that the two inventions were not.  As a first step, claim construction, the Federal Circuit agreed that the "co-administering" limitation did not mean "administration of the antibody alone after discontinuing treatment with methotrexate."7  "Put simply," based on the specification of the '766 patent, "co-administration" meant "administration of both drugs at the same time," and "cannot include patients who discontinued methotrexate as Kennedy contends."8  The Federal Circuit then assumed, without deciding, that Kennedy's definition of the term "active disease"—"the presence of six or more swollen joints plus at least three of four secondary criteria"—was correct for the purposes of its OTDP analysis.9 Given Kennedy's definition of "active disease," the court noted that "the genus claimed in the '766 patent (treating all patients in need thereof) is broader than the species claimed in the '442 patent (treating patients with 'active disease,' i.e., particularly sick patients)."10  While Kennedy admitted that the claims of the '442 patent were encompassed by the claims of the '766 patent, Kennedy argued that the species claims were separately patentable.11  The Federal Circuit reminded that, indeed, "a narrow species can be non-obvious and patent eligible despite a patent on its genus," but that "not every species of a patented genus is separately patentable."12 

In the second step of the OTDP analysis—whether the differences in the subject matter between the claims render them patentably distinct—the Federal Circuit found the later-expiring claims were obvious over the earlier claims.  In particular, the court found that the later claims of the '442 patent applying to sicker patients with "active disease" were specific as compared to the '766 patent claims directed to a broader patient population.  According to the court, "species are unpatentable when prior art disclosures describe the genus containing those species such that a person of ordinary skill in the art would be able to envision every member of the class."13 

The court further found that there were no unexpected results with respect to the "active disease" group when compared to the known utility disclosed in the specification of the '766 patent.14  The court was free to "look to a reference patent's disclosures of utility to determine the question of obviousness," even if the reference patent's specification cannot technically be used as prior art in the OTDP analysis.15  The Federal Circuit stated that "[w]e have repeatedly approved examination of the disclosed utility of the invention claimed in an earlier patent to address the question of obviousness."16  Accordingly, the claims of the '422 patent were deemed to have been obvious over the '766 patent claims, rendering them invalid for OTDP.17 

The Federal Circuit has addressed the issue of OTDP several times over the last two decades.18  As evidenced in the AbbVie decision, the doctrine can reach some very specific circumstances, including where two patents claim the same invention, but have different expiration dates due to different priority assertions.

Footnotes

1 Because of the URAA, patents filed on or before June 15, 1995, have a base term of seventeen years from the date of issue; patents filed after June 15, 1995, have a base term of twenty years from the date of filing.

2 See AbbVie Inc. v. Mathilda & Terence Kennedy Inst. of Rheumatology Trust, No. 2013-1545, slip op. at 10-11 (Fed. Cir. Aug. 21, 2014).

3 Id. at 11 (citations omitted).

4 Id. at 11-12 n.2. 

5 Id. at 11-12. 

6 Id. at 13.

7 Id. at 15. 

8 Id. at 17. 

9 Id. at 19-20.

10 Id. at 20-21.

11 Id. at 4. 

12 Id. at 23.

13 Id. at 24. 

14 Id. at 26. 

15 Id. ("[W]hile . . . it is impermissible to treat a patent disclosure as though it were prior art in a double patenting inquiry, . . . the disclosure may be used . . . to answer the question whether claims merely define an obvious variation of what is earlier disclosed and claimed." (citation and internal quotation marks omitted)).

16 Id. at 26-27 (citing Geneva Pharm., Inc. v. GlaxoSmithKline PLC, 349 F.3d 1373, 1386 (Fed. Cir. 2003)).

17 Id. at 28. 

18 See, e.g., Gilead Scis., Inc. v. Natco Pharma Ltd., 753 F.3d 1208 (Fed. Cir. 2014); Sun Pharm. Indus., Ltd. v. Eli Lilly & Co., 611 F.3d 1381 (Fed. Cir. 2010); In re Fallaux, 564 F.3d 1313 (Fed. Cir. 2009); In re Basell Poliolefine Italia S.P.A., 547 F.3d 1371, 1375 (Fed. Cir. 2008); In re Metoprolol Succinate Patent Litig., 494 F.3d 1011, 1016 (Fed. Cir. 2007); Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 967 (Fed. Cir. 2001); In re Berg, 140 F.3d 1428, 1433 (Fed. Cir. 1998); In re Emert, 124 F.3d 1458 (Fed. Cir. 1997). 

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