By Donald Zuhn --
On July 23, 2007, the Federal Circuit affirmed by a 2-1 vote a District Court judgment that U.S. Patent No. 5,081,154 (the '154 patent) was invalid for double patenting. The Federal Circuit also vacated the District Court's holding that the '154 patent and U.S. Patent No. 5,001,161 (the '161 patent) were unenforceable based on inequitable conduct, and remanded the case.
Plaintiffs AstraZeneca AB, Aktiebolaget Hässle, and AstraZeneca LP (AstraZeneca) own the '161 and '154 patents. The lone claim of the '161 patent recites "[a] pharmaceutical composition comprising metoprolol succinate together with a sustained release pharmaceutically acceptable carrier," and the lone claim of the '154 patent recites "[m]etoprolol succinate." AstraZeneca markets metoprolol succinate, the salt of metoprolol with succinic acid, in "extended release" form under the trademark Toprol-XL®. Toprol-XL® is used for treating angina, hypertension, and congestive heart failure.
Seeking approval to market generic metoprolol succinate, Defendants KV Pharmaceutical Co. (KV), Andrx Pharmaceuticals, LLC, and Andrx Corp. (Andrx), and Eon Labs, Inc. (Eon) filed separate Abbreviated New Drug Applications (ANDAs) with the FDA. In response, AstraZeneca sued the Defendants for infringement of the '161 and '154 patents, bringing suit against KV in the Eastern District of Missouri and suing Andrx and Eon in separate actions in Delaware. The three suits were consolidated in the Eastern District of Missouri.
All three Defendants moved for summary judgment of invalidity of the '161 and '154 patents based on double patenting and invalidity of the '161 patent based on anticipation. Andrx also moved for summary judgment of unenforceability of the '161 and '154 patents based on inequitable conduct (KV and Eon subsequently joined this motion). AstraZeneca moved for partial summary judgment of validity of the '154 patent.
The basis of the Defendants' double patenting motion was U.S. Patent No. 4,780,318 (the '318 patent), which, along with the '161 and '154 patents, could be traced back to the filing of a Swedish patent application in 1984. Thirteen years before that filing, an AstraZeneca employee named Toivo Nitenberg synthesized metoproplol succinate. Eleven years after Nitenberg's discovery, an AstraZeneca employee named Lars Lilljequist - possibly at the direction of AstraZeneca employees Curt Appelgren and Christina Eskilsson - synthesized a number of metoprolol salts, including metoproplol succinate.
In 1983, Appelgren and Eskilsson left AstraZeneca to join Lejus Medical AB (Lejus), the assignee of the '318 patent. One year later, Lejus filed a Swedish patent application describing "delayed and extended release dosage forms of pharmaceutical compositions, including metoprolol succinate." In 1985, Lejus filed a U.S. patent application claiming the benefit of the Swedish application.
After noticing the publication of the Swedish application, AstraZeneca initiated a transfer of ownership action with the Swedish Patent Office, contending that Nitenberg, and not Appelgren and Eskilsson, had invented metoproplol succinate. AstraZeneca and Lejus settled the ownership dispute, with Lejus agreeing to divide out claims to metoproplol succinate and pharmaceutical compositions containing metoproplol succinate from the 1985 U.S. filing and assign the divided claims to AstraZeneca. The settlement agreement, however, continued to list Appelgren and Eskilsson as inventors of the divided metoproplol succinate claims, since the agreement merely resolved the issue of ownership and not the issue of inventorship. Lejus subsequently filed a continuation-in-part application of the 1985 U.S. filing (containing only the undivided claims), which issued as the '318 patent.
Claim 6 of the '318 patent recites an improved release oral pharmaceutical composition having (i) "a core comprising the therapeutically active compound," (ii) "a first inner layer coating on the core," and (iii) "a second outer layer coating on the inner layer." Claim 8 specifies that the therapeutically active compound of claim 6 may be one of eleven compounds including metoproplol succinate.
The District Court granted both of the Defendants' summary judgment motions and denied AstraZeneca's motion. With respect to the double patenting motion, the District Court determined that the '154 patent claimed a genus of the species claimed by the '318 patent, and since the '318 patent issued before the '154 patent, the '154 patent was "void for double patenting because it is not patentably distinct f[ro]m" claim 8 of the '318 patent.
The Federal Circuit cited its decision in In re Emert as dictating that it affirm the District Court's finding of double patenting, and stated that AstraZeneca had "offer[ed] no convincing reason why Emert does not apply." In comparing Emert and the instant case, the Federal Circuit observed that "in this case, Claim 1 of the '154 Patent claiming a compound (A1) is an obvious variation of Claim 8 of the '318 Patent claiming a composition comprised of one compound of an enumerated list (A1, A2, A3, etc.), an inner layer (B), and an outer layer (C)," and therefore that "it would have been an obvious variation of Claim 8 of the '318 Patent to omit the inner layer (B) and the outer layer (C)." Citing the Supreme Court's decision in KSR Int'l Co. v. Teleflex Inc., the Federal Circuit also noted 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.'"
Judge Schall, dissenting from the majority's holding of invalidity by reason of obviousness-type double patenting, stated that "[a]nything less than a compound . . . having (i) a core with any one of eleven possible compounds, one of them being metoprolol succinate; (ii) an inner coating; and (iii) an outer coating . . . is not what is claimed," and "[i]n contrast, what is claimed by claim 1 of the '154 patent is a single compound: metoprolol succinate." Thus, for Judge Schall, since "[a] double patenting analysis turns on what is claimed," and "the compound metoprolol succinate has not 'been claimed twice,'" the majority should have reversed the District Court's finding of invalidity.
In response to the District Court's policy argument that if the '161 and '154 patents were found valid, "they would prevent the public from using the earlier issued invention of claim 8 of the '318 patent upon its expiration because they completely encompass claim 8 as to metoprolol succinate," Judge Schall countered that:
Allowance of claim 1 of the '154 patent to metoprolol succinate will not result in the improper extension of the patent for the invention claimed in the '318 patent. That is because in this case, each patent is capable of being practiced by itself, without infringing the other. The public can practice the invention in claim 8 of the '318 patent when it expires by using any of the ten active ingredients recited in the claim other than metoprolol succinate. While some may find it desirable to use metoprolol succinate as the active ingredient in claim 8 of the '318 patent, and those individuals will be unable to do so until the '154 patent expires, that does not result in the "extension" of claim 8 in the '318 patent, or in any recognized form of double patenting.
In re Metoprolol Succinate Patent Litigation (Fed. Cir. 2007)
Panel: Circuit Judges Mayer, Schall, and Gajarsa
Opinion by Circuit Judge Gajarsa; dissent in part by Circuit Judge SchallAdditional information regarding this case can be found at the Orange Book Blog and Patently-O.
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