The opinion of the court was delivered by: Lewis A. Kaplan, District Judge.
Plaintiff charges defendants with infringing its patent for the synthesis of a chemical compound used in the manufacture of certain pharmaceuticals by selling in the United States the antidepressant drug citalopram, which defendants allegedly made in part by using plaintiff's patented process. The matter is before the Court on defendants' motion for partial summary judgment.
Plaintiff Infosint, S.A. ("Infosint") owns the patent at issue in this case, U.S. Patent No. 6,458,973 (the "'973 patent"), which claims an improved process for making the compound 5-carboxyphthalide, a compound used as an intermediate product in the synthesis of citalopram and escitalopram. Citalopram and escitalopram are well-known antidepressants marketed in the United States.*fn1 Plaintiff filed its application for what issued as the '973 patent with the U.S. Patent and Trademark Office ("PTO") on October 17, 2000.*fn2
The compound 5-carboxyphthalide had been synthesized successfully prior to the inventors' patent application. What the inventors claimed was a superior manufacturing process, including innovations that permitted the reaction to occur in open and non-pressurized reactors, which were especially useful for large scale production in an industrial setting.*fn3
In general terms, the claimed process involves adding terephthalic acid to fuming sulfuric acid containing at least 20 percent sulfur trioxide, SO3. Fuming sulfuric acid, also known as oleum,*fn4 is a mixture of sulfuric acid and sulfur trioxide.*fn5 Next, formaldehyde or a formaldehyde precursor*fn6 is added to the mixture, which is heated at 120-145§ C. The resulting 5-carboxyphthalide then is isolated from the solution.*fn7
Defendants, H. Lundbeck A/S and subsidiary Lundbeck, Inc. (collectively "Lundbeck"), as well as Forest Laboratories, Inc., and Forest Pharmaceuticals, Inc. (collectively "Forest"), manufacture, market, and sell citalopram and escitalopram.*fn8 Lundbeck synthesizes 5-carboxyphthalide at seven facilities located outside of the United States. It manufactures citalopram and escitalopram in Denmark.*fn9 Forest markets and sells these pharmaceuticals in the United States under the trademarks Celexa and Lexapro, respectively.*fn10
Plaintiff alleges that Lundbeck uses 5-carboxyphthalide made according to the process described in the '973 patent as an intermediate product in its production of citalopram and escitalopram. Defendants counterclaim, asserting that several claims in Infosint's '973 patent interfere with claim 1 of Lundbeck's U.S. Patent No. 6,403,813, (the "'813 patent"), which discloses its own process for synthesizing 5-carboxyphthalide.*fn11 That method comprises also a "reaction of terephthalic acid with paraformaldehyde... in oleum."*fn12
According to defendants, Poul Dalhberg Nielsen, a Lundbeck chemist,*fn13 invented the process claimed in the '813 patent no later than 1986.*fn14 They assert that they publically disclosed this process in the United Kingdom to Her Majesty's Inspectorate of Pollution in 1994.*fn15 Lundbeck then filed an application for a Danish patent claiming the process on November 1, 1999.*fn16 On October 19, 2000, two days after Infosint filed its application for what issued as the '973 patent, Lundbeck also submitted an application to the PTO.*fn17 Lundbeck's U.S. application disclosed the same process that Lundbeck described in its Danish application and claimed a priority date based on that application.*fn18 The PTO issued defendants' '813 patent on June 11, 2002.*fn19 It issued Infosint's '973 patent on October 1, 2002.*fn20
Summary judgment is appropriate if there is no genuine issue of material fact and the moving party is entitled to judgment as a matter of law.*fn21 The Court must view the facts in the light most favorable to the nonmoving party,*fn22 and the moving party has the burden of demonstrating the absence of a genuine issue of material fact.*fn23 Where the burden of proof at trial would fall on the nonmoving party, however, it ordinarily is sufficient for the movant to point to a lack of evidence on an essential element of the nonmovant's claim.*fn24 In that event, the nonmoving party must come forward with admissible evidence*fn25 sufficient to raise a genuine issue of fact for trial or suffer an adverse judgment.*fn26
Defendants contend that Infosint's '973 patent interferes with Lundbeck's '813 patent. They allege also that they were the first to invent the interfering subject matter and that the '973 patent therefore is invalid under Section102(g)(1) of the Patent Act (the "Act").*fn27 They contend also that the '973 patent is invalid under Section 103 of the Act*fn28 because prior art exclusive of Lundbeck's own patent rendered the '973 patent's claims obvious.*fn29
A patent interferes with the patent of another when the two patents "have the same or substantially the same subject matter in similar form."*fn30 Section 291of the Act*fn31 provides that "[t]he owner of an interfering patent may have relief against the owner of another by civil action, and the court may adjudge the question of the validity any of the interfering patents, in whole or in part."
A district court has jurisdiction under Section 291 only if the alleged interference is established.*fn32 The first step in an interference proceeding therefore is to determine whether an interference in fact exists.*fn33 To do so, the federal courts, like the PTO, rely on a two-way test*fn34 in which:
"[t]he claimed invention of Party A is presumed to be prior art vis-a-vis Party B and vice versa. The claimed invention of Party A must anticipate or render obvious the claimed invention of Party B and the claimed invention of Party B must anticipate or render obvious the claimed invention of Party A."*fn35
This test incorporates the standards for both anticipation and obviousness under Sections 102 and 103, respectively, permitting either circumstance to satisfy one leg of the two-way test.*fn36 When comparing issued patents under Section 291, courts compare the disputed claims only, not the specifications or any other disclosures of each patent.*fn37
Here, defendants allege that claim 1 of their '813 patent interferes with claims 1, 21, 23, and 24 of Infosint's '973 patent. Claim 1 of the '813 patent encompasses "[a] method for the preparation of 5-carboxyphthalide comprising reaction of terephtalic acid with paraformaldehyde HO(CH2)nH in oleum."*fn38 The '973 patent claims in relevant part:
"1. A process for the preparation of 5-carboxyphthalide... which comprises adding formaldehyde and terephtalic acid... to fuming sulfuric acid containing at least 20% of SO3, heating the mixture at 120-145N C. and isolating the 5-carboxyphthalide thus obtained.
"21. A process for the synthesis of citalopram, in which a process for the synthesis of 5-carboxyphthalide ...