In In re Metoprolol Succinate Patent Litigation, 83 U.S.P.Q.2d 1545 (Fed. Cir. 2007), Lejus Medical AB filed application no. 690,197 (the ‘197 application) in 1985. The ‘197 application described “delayed and extended release dosage forms of pharmaceutical compositions, including metoprolol succinate.” During prosecution, an inventorship dispute arose between Lejus and Astrazeneca. As a result of a settlement resulting from this inventorship dispute, Lejus agreed to divide the claims in the ‘197 application into claims to “metoprolol succinate,” which was to be owned by Astrazeneca, and claims to “pharmaceutical composition, characterized by the active substance is metoprolol succinate” to be owned by Lejus.
Lejus cancelled the claims to the metoprolol succinate in the ‘197 application, and subsequently filed a continuation application to the metoprolol succinate, which it assigned to Astrazeneca. Lejus continued prosecution of the ‘197 application for the remaining claims, which eventually resulted in U.S. Patent 4,780,318 (the ‘318 patent) in 1988. Claim 8 if the ‘318 patent claims:
8. Pharmaceutical composition according to claim 7 [A core comprising the therapeutically active compound, a first inner layer coating on the core, and a second outer layer coating on the inner layer] wherein the active compound is quinidine sulphate, quinidine bisulphate, quinidine gluconate, quinidine hydrochloride, metoprolol tartrate, metoprolol succinate, metoprolol fumarate, furosemide, 5-aminosalicylic aicd [sic], propranolol or alprenolol or a pharmaceutically acceptable salt therof, or a mixture thereof with another weak base, weak acid, or salt thereof having a pka of 1 to 8. (emphasis added)
Astrazeneca was issued two patents, both continuations of the ‘318 patent, of which only one was appealed in this case: U.S. Patent 5,081,154 (the ‘154 patent). The ‘154 issued in 1992 and claims simply:
1. Metoprolol succinate.
During the prosecution of its patents, Astrazeneca did not notify the examiners about the previous inventorship dispute.
Astrazeneca brought infringement actions against several defendants. On summary judgment, the District Court ruled Astrazeneca’s ‘154 patent was invalid due to obviousness type double patenting over the ‘318 patent and additionally ruled the ‘154 patent unenforceable due to inequitable conduct.
Invalidity due to Obviousness Type Double Patenting
In affirming the District Court’s ruling that the ‘154 patent was invalid due to obviousness type double patenting, the Federal Circuit noted that “[n]on-statutory, or ‘obviousness-type,’ double patenting is a judicially created doctrine adopted to prevent claims in separate applications or parents that do not recite the ‘same’ invention, but nonetheless claim inventions so alike that granting both exclusive rights would effectively extend the life of patent protection.” Determining double patenting is completed in two steps: first by construing each of the claims in the patents at issue, then second by determining whether the claims are patentably distinct.
On appeal, the only dispute was the second step: the comparison of the claims. The District Court found that because the ‘154 patent “broadly claims any pharmaceutical compositions containing metoprolol succinate”, the ‘154 patent was a genus as compared to the ‘318 patent issued prior, which is a species of the genus and is drawn to the pharmaceutical composition including the metoprolol succinate. Since a genus is obvious in view of a prior disclosed species, the District Court found the ‘154 patent was patently indistinct and void for obviousness type double patenting.
Astrazeneca specifically contested the characterization that the claims were in a genus species relationship and were instead were in a patentably distinct element-combination relationship. In rejecting AstraZeneca’s argument, the Federal Circuit held that “the characterization of the relationship” is irrelevant and “the critical inquiry remains whether the claims in the [latter application] define an obvious variation of the invention claimed in the [former] patent” In re Emert, 124 F.3d 1458, 44 U.S.P.Q.2d 1149 (Fed. Cir. 1997). The Federal Circuit specifically analogized the instant claims with the situation in In re Emert, where a claim for B1 was found obvious in light of a claim to [A and B]. In In re Emert, since the differences between B and B1 were conceded to be not material, the Federal Circuit found that because it would have been an obvious variation to omit the inner and outer layers, the patent in In re Emert was invalid for double patenting. Since the Federal Circuit viewed the claims in the ‘154 and ‘318 patents as being in the same basic relationship as existed in In re Emert, the Federal Circuit found that the claims were patentably indistinct, and that the later filed genus claim was thus invalid under In re Emert.
The Federal Circuit also rejected Astrazeneca’s reliance on three cases from the Court of Customs and Patent Appeals which stand for the preposition that there is no obviousness type double patenting if a later application sets out an element found in a previously issued combination. In re Walles, 366 F.2d 786 (C.C.P.A. 1966); In re Allen, 343 F.2d 482 (C.C.P.A. 1965); In re Heinle, 342 F.2d 1001 (C.C.P.A. 1965). While acknowledging that these cases do support AstraZeneca’s position, the Federal Circuit held that a later issued opinion from the C.C.P.A., In re Schneller, 397 F.2d 350, 158 USPQ 210 (C.C.P.A. 1968), limited these cases to their facts.
In In re Schneller , the Court of Customs and Patent Appeals affirmed a rejection where the applicant’s “first application disclosed ABCXY and other matters. He obtained a patent claiming BCX and ABCX, but so claiming these combinations as to cover them no matter what other feature is incorporated in them, thus covering effectively ABCXY. He now, many years later, seeks more claims directed to ACBY and ABCXY. Thus, protection he already had would be extended, albeit in somewhat different form, for several years beyond the expiration of his patent.” As such, the Federal Circuit found that Schneller limited In re Walles; In re Allen; In re Heinle to their facts.
The Federal Circuit noted that the same situation occurred in the instant appeal. Specifically, Lejus first obtained a patent claiming (A1, A2, A3, etc.)BC in Claim 6 of the ’318 Patent. Astrazeneca later obtained a patent claiming A1 in Claim 1 of the ’154 Patent. Therefore, the Federal Circuit found that the later issued genus claim was rendered obvious by the prior issued species claim.
Unenforceability for Failure to Disclose Inventorship Dispute in Related Application
The Federal Circuit vacated the District Court’s determination of inequitable conduct and remanded on this issue. The Federal Circuit focused on whether Astrazeneca had an intent to deceive when prosecuting its patents with regards to the inventorship dispute. The District Court had inferred an intent to deceive due to the severe negative side effects had the inventorship dispute been related to the office and the inventor determined differently. According to the District Court, this intent to deceive would have been to prevent the loss of the effective filing date, which would have been lost and the patent would have been anticipated by Lejus’ patent application published abroad.
However, the Federal Circuit rejected the District Court’s “but for” analysis above. Specifically, the Federal Circuit noted that there was no evidence of this concern, and noted that the deposition of AstraZeneca’s in-house patent counsel indicated “that he did not know of and was not concerned about the incentives identified by the district court.” This lack of evidence raised a substantial issue of fact regarding intent to deceive that was not properly disposed of at summary judgment. As such, the issue was remanded for further consideration.
Significance for Patent Applicants
In re Metoprolol Succinate Patent Litigation demonstrates a difficulty which will be faced by applicants in maintaining separate pending applications for components and systems using the components under the new Claims and Continuation rules. As more thoroughly set forth in the Feature Comment: An Overview Of USPTO Issues New Continuation And Claim Limitation Rules And Proposed Strategic Responses below, the new Claims and Continuation rules penalize applicants having copending applications with patentably indistinct claims. Specifically, under In re Metoprolol Succinate Patent Litigation, patentably indistinct claims can exist where there is a genus-species relationship as well as a component-system relationship. Thus, in addition to traditional obviousness type double patenting issues, applicants need to be prepared for possible 37 CFR 1.75 and 37 CFR 1.78 issues which will arise after November 1.