By Kevin E. Noonan --
Over seven years ago, the Federal Circuit delivered a mixed ruling against Pfizer in litigation against Teva) relating to the pain medication Celebrex® (celocoxib) (where "celocoxib" is 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide). In that case, Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc. (Fed. Cir. 2008), the Court upheld a District Court determination that Teva was liable for infringing a trio of Pfizer patents (U.S. Patent Nos. 5,466,823; 5,563,165; and 5,760,068) but reversed the District Court's determination that the claims of the '068 patent were not invalid for obviousness-type double patenting. Pfizer took steps to remedy the deficiency of the claims of the '068 patent by reissue, but those efforts were deemed insufficient in a decision handed down today in G.D. Searle LLC v. Lupin Pharmaceuticals Inc. et al.
This case involved ANDA litigation against five generic defendants (Lupin, Teva Pharmaceuticals USA Inc., Mylan Pharmaceuticals Inc., Watson Laboratories, Inc., Apotex Inc. and Apotex Corp.), again related to generic Celebrex. The basis for the Court's earlier determination that the '068 patent was invalid for obviousness-type double patenting was that the designation of this patent as a "continuation-in-part" was not merely semantic but had substantive repercussions regarding whether the '068 claims were entitled to the "safe harbor" provisions of 35 U.S.C. § 121. These provisions entitle a divisional application filed as the result of a restriction requirement (a Patent Office determination that an applicant has filed claims directed to more than one invention) to be exempt from obviousness-type double patenting, and illustrate Congressional intent (from the legislative history of the 1952 Patent Act) to prevent the unfairness of forcing an applicant to be required to file a divisional application based on claiming "independent inventions" through restriction while permitting the original application to be used as "prior art" in a obviousness-type double patenting rejection. The Federal Circuit considered it also Congress's intent to restrict the safe harbor to divisional applications (which have an identical specification to the originally-filed application) and keep any claims in such a divisional application strictly within the bounds of what had been determined to be a separate invention. This meant, for example, that an applicant would not be able to include claims in a divisional that were within the scope of any claims previously elected for examination. In this way applicants would be precluded from inequitably increasing patent term while not being penalized for electing one invention and pursuing additional inventions in divisional applications.
The lineage of the '068 patent began with U.S. patent application No. 08/160,594 in which the U.S. Patent and Trademark Office imposed a three-way restriction requirement: to the claimed compounds per se, compositions of said compounds and methods of use for treating inflammation and resulting pain without the side effects of conventional non-steroidal anti-inflammatory compounds. The compound claims were elected and granted as U.S. Patent No. 5,466,823 and the composition claims pursued in a divisional application (Serial No. 08/457,059) that issued as U.S. Patent No. 5,563,165. Both the '823 and '165 patents have expired.
Pfizer did not pursue the method of treatment claims in a divisional application but instead filed a continuation-in-part application that contained additional disclosure (including previously undisclosed compounds) as well as claims to the three classes of inventions that were subject to restriction in the '594 application. The U.S. application issued as U.S. Patent No. 5,521,207 and is also expired. However, this application was the priority document for a PCT (International) Application that entered the national phase in the U.S. as Serial No. 08/648,113. In that application the PTO imposed a unity of invention/restriction requirement along exactly the same lines as in the '594 application, requiring the applicant to choose between claims to the compounds, compositions, and method of treatment claims. Pfizer chose to pursue the method of treatment claims and these claims ultimately granted in the '068 patent.
In the earlier litigation, the Federal Circuit found that the claims of the '068 patent did not fall within the safe harbor because it was a continuation-in-part application, not a divisional. Such a "CIP" application by definition contains some of the disclosure of an earlier-filed application in addition to new disclosure. Because of this distinction, the Federal Circuit found that CIP applications could not fall within the safe harbor because they could encompass additional information (and patentable inventions) that were not a part of the original, restricted claims.
After receiving this decision, Pfizer filed reissue application No. 12/205,319 under 35 U.S.C. § 251 seeking to amend the '068 patent to conform to the requirements for a divisional application. According to the panel decision today, in its reissue declaration "Pfizer asserted that it had erred in prosecuting the application leading up to the '068 patent as a continuation-in-part, rather than as a divisional application, and that the error had resulted in invalidating the relevant claims of the '068 patent for obviousness-type double patenting." Pfizer filed a preliminary amendment wherein:
(1) it deleted portions of the '068 patent specification that were not present in the '594 application; (2) it designated the '113 application as a divisional of the '594 application and removed the priority claim to the '629 application; (3) it amended claim 1 to be a method claim using only the compounds originally disclosed in the '594 application; (4) it canceled claims 2-12, which were method claims using compounds that were not present in the '594 application; (5) it canceled claim 18 (reciting a method of preventing colorectal cancer), which was not found in the '594 application; and (6) it added new method claims 19-23, which recited the use of the method disclosed in claim 1 to treat five specific types of inflammation-associated disorders.
Initially the PTO rejected the reissue application on the grounds that these changes were not the types of error intended to be remedied by reissue; in response Pfizer amended its amendment to assert "various technical errors" that Pfizer contended rendered the claims indefinite, and on that basis the reissue application was permitted to continue. Pfizer then made the changes in the original version of the application and the application granted as RE44,048.
The District Court held that these corrections were not correctable under the reissue statute, and that the claims in the '048 reissue patent were not entitled to the safe harbor under 35 U.S.C. § 121 and thus were invalid for obviousness-type double patenting.
The Federal Circuit affirmed, in an opinion by Judge Bryson joined by Chief Judge Prost and Judge Hughes. The opinion recognized the question of the propriety of the reissue application under § 251 but was content to limit the decision to the absence of the safe harbor under § 121 for the reissue claims. The panel expressly rejected Pfizer's argument that the restriction requirement from the '594 application extended to the national phase of the PCT application, despite the similarities in the nature of three classes of claims in each. The panel reasoned that this cannot be the case because the national phase '113 application contained new matter not contained in the '594 application and thus was properly treated as a continuation-in-part (the earlier case had expressly held that CIPs were not entitled to the safe harbor provisions of § 121). In this regard the panel rejected the changes in the reissue application, stating that "[s]imply deleting that new matter from the reissue patent does not retroactively alter the nature of the '113 application."
The opinion also raises the equities (between Pfizer and the public) involved:
Moreover, when the '113 application issued as the '068 patent in June 1998, Pfizer obtained patent protection for the new matter that was not present in the '594 application. For years thereafter, the public was not free to practice that new matter (e.g., the now cancelled claims 2-12 and 18 of the '068 patent) because of that patent protection. Pfizer cannot now identify the '113 application as a divisional of the '594 application (for purposes of section 121) and retroactively relinquish the new matter in the '113 application, after having enjoyed years of patent protection for it. See In re Harita, 847 F.2d 801, 809 (Fed. Cir. 1988) ("In any given case, the [reissue] statute should be so applied to the facts that justice will be done both to the patentee and the public."); see also In re Serenkin, 479 F.3d 1359, 1362 (Fed. Cir. 2007) ("[Section] 251 is based on fundamental principles of equity and fairness[.]"). Fairness to the public does not permit Pfizer to convert the '113 application into a division of the original '594 application, and thereby take advantage of the safe harbor provision, simply by designating it as a divisional application years after the fact.
(This rationale also applies to the foreign patents arising from the PCT application, whose status has not changed.)
The opinion also sets forth as a basis for its decision its determination that the restriction requirement in the '113 application is not the same as the restriction requirement in the '594 application (despite their similarities). The panel states that the claims in divisional applications must be "derived from the same restriction requirement," citing its earlier opinion regarding this patent family and also Boehringer Ingelheim Int'l GmbH v. Barr Labs., Inc., 592 F.3d 1340, 1354 (Fed. Cir. 2010), stating:
When separate restriction requirements are imposed on separate applications and the record does not show that any of the various restriction requirements carried forward from one application to the next, the earlier restriction requirement cannot be viewed as having continued in effect with respect to the later-filed application [citing Bristol-Myers Squibb Co. v. Pharmachemie B.V., 361 F.3d 1343, 1349-50 (Fed. Cir. 2004)].
The record here was that there were two separate restriction requirements asserted in two related but distinct (regarding the disclosure in the specification and the subject matter of the claims) applications, and that these differences precluded the restriction requirement imposed in the '594 application from having "carried over" to the '113 application (and the panel noted there was no evidence that the '113 application examiner referenced or was even aware of the restriction in the '594 application). And the Court expressly rejected Pfizer's "but for" argument with regard to the requirement imposed in the '594 application (that "but for" that restriction the method of treatment claims would have been prosecuted in the '594 application).
While this decision is entirely consistent with the Court's earlier Pfizer decision, it does illustrate how stringently the Court has and intends to apply the law of obviousness-type double patenting for pharmaceutical patents.
G.D. Searle LLC v. Lupin Pharmaceuticals, Inc. (Fed. Cir. 2015)
Panel: Chef Judge Prost and Circuit Judges Bryson and Hughes
Opinion by Circuit Judge Bryson