Ex parte Schwarcz
| Decision Date | 22 September 2016 |
| Docket Number | Appeal 2015-001426 |
| Parties | Ex parte ROBERT SCHWARCZ, Y ASUSHI KAJII, and SHIN-ICHIRO ON0 Application No. 12/742, 171 Technology Center 1600 |
| Court | Patent Trial and Appeal Board |
Before JEFFREY N. FREDMAN, JOHN G. NEW, and JOHN E. SCHNEIDER Administrative Patent Judges.
NEW Administrative Patent Judge.
Appellants file this appeal under 35 U.S.C. § 134(a) from the Examiner's Final Rejection of claims 23[2] as unpatentable under 35 U.S.C. §103 (a) as being obvious over the combination of Schriewer et al. (US 5, 237, 060, August 17, 1993) ("Schriewer"), Desideri et al. (US 4, 758, 567 July 19, 1988) ("Desideri"), and Ueda et al. (US 5, 591, 744, January 7, 1997) ("Ueda").
We have jurisdiction under 35 U.S.C. § 6(b)
We AFFIRM.
Appellants' invention is directed to compounds of formula (I), prodrug derivatives and/or pharmaceutically acceptable salt thereof, which selectively inhibit the enzyme kynurenine aminotransferase, thereby reducing the synthesis of kynurenic acid. The compounds are used for the treatment of psychiatric and neurological diseases which benefit from an increase in glutamatergic and/or cholinergic neurotransmission, such as schizophrenia, depression, bipolar illness, anxiety and Alzheimer's disease. Furthermore, the compounds of the invention are useful for stimulating attention, memory and other cognitive processes in normal individuals of any age, including children, adolescents and the elderly. Additionally, the compounds of the invention are also useful for treatment of patients suffering from malaria by preventing parasite gametogenesis and fertility based on reduction of xanthurenic acid formation from its bioprecursor 3hydroxy kynurenine. Abstract.
Claim 23 is the sole claim on appeal, and recites:
23. A compound having the following structure:
(Image Omitted)
and is (S)-(-)-9-(4-Aminopiperazin-l-yl)-8-fluoro-3-methyl-6-oxo-2, 3dihydro-6H-1-oxa-3a-aza-phenalene-5-carboxylic acid, (S)-(-)-9-(4Aminopiperazin-1-y 1)-8-fluoro-3-methyl-6-oxo-2, 3-dihydro-6H-1-oxa -3a-aza-phenalene-5-carboxylic acid ethyl ester or a pharmaceutically acceptable salt thereof in an effective amount to inhibit the synthesis of kynurenic acid.
We agree with, and adopt, the Examiner's findings and conclusion that the appealed claim is primafacie obvious over the cited prior art references. We address the arguments raised by Appellants below.
Appellants argue the Examiner erred in finding the combined cited prior art teaches or suggests all of the limitations of claim 23 App. Br. 7.
Appellants point to each of the references in tum, arguing that none of them, singly or in combination with the others, teaches or suggests all of the limitations of claim 23. App. Br. 7.
With respect to Desideri, Appellants argue that the basic structure taught by Desideri is as follows:
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The basic structure claimed by Desideri as recited in column 1 lines 13-33
Additionally Appellants point to Example 5 of Desideri, which, when read in light of Example 3 and upon which the Examiner relies, teaches the following structure:
(Image Omitted)
The structure of Examples 3 and 5 of Desideri (N-amino--norfloxacine) as depicted in Examiner's Answer at 3. App. Br. 8. Appellants point out that although this structure possesses an amino group on the piperazine ring, this and all of the embodiments claimed by Desideri lack the requisite morpholine ring as shown in claim 1.
Appellants point next to Schriewer, which teaches, inter alia, the following structure:
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The structure taught by Schriewer at column 20, lines 2-11 App. Br. 9 (citing Schriewer Exs. 4, 16). Appellants contend Schriewer is directed to methods of synthesizing the antibiotic ofloxacin, which necessarily requires that a methyl group be attached to the piperazine ring, rather than an amino group, as required by claim 23. Id. Consequently, argue Appellants, there is no teaching or suggestion in Schriewer that would direct a person of ordinary skill to replace the "important" methyl (i.e., "alkyl") group on the piperazine ring. Id. Appellants also contend there is no direction in either Desideri or Schriewer that would inform a person of ordinary skill which elements of each reference to combine and which to delete. Id. at 10.
Appellants next point to the Examiner's citation to Ueda, which Appellants argue adds nothing relevant to the teachings of Desideri and Schriewer. App. Br. 11. Ueda teaches the following basic structure:
(Image Omitted)
Novel antimicrobial benzoheterocyclic compound taught by Ueda at column 1, lines 7-13.
Appellants admit that Ueda teaches substitution at the R2 position is defined as a 5 to 9-membered saturated or unsaturated heterocyclic ring which may be substituted by, inter alia, an amino-substituted piperazine ring, as recited in claim 1. App. Br. 14. However, Appellants argue, that substitution is contained in six columns of possible substitutions. App. Br. 11-13 . Appellants argue that a person of ordinary skill would not have motivation to extract this embodiment from the list without using Appellants' Specification as a map to arrive at the claimed composition.
Appellants argue that, to successfully demonstrate that a new compound is obvious, the Examiner must show "that the prior art would have suggested making the specific molecular modifications necessary to achieve the claimed invention." App. Br. 15 (quoting Takeda Chemical Industries Ltd. v. Alphapharm Pty. Ltd., 492 F.3d 1350, 1356 (Fed. Cir. 2007)). Therefore, Appellants argue, in addition to structural similarity between the compounds, a prim a facie case of obviousness may be shown by "adequate support in the prior art" for the change in structure. Id. (quoting In re Grabiak, 769 F.2d 729, 732 (Fed. Cir. 1985)). As such, Appellants assert, the Examiner must identify some reason that would have led a chemist to modify a known compound, to establish a prima facie case of obviousness for a new claimed compound. Id.
The Examiner responds that, given that both the 4-amino group on the piperazine ring and tricyclic core features of Appellants' invention are explicitly taught in the references, one skilled in the art would have been motivated to replace the 4-methyl of Schriewer's compounds with a 4-amino or, alternatively, replace the quinoline core of Desideri with the instant core in view of the combined teachings outlined above.
We are not persuaded by Appellants' arguments. Schriewer teaches a composition that is essentially identical to Appellants' claimed composition with the single exception that the 4-substituted methyl group on the piperazine ring of Schriewer has been substituted with an amino group in the composition of claim 23. We agree with the Examiner that such a simple substitution would have been obvious to a person of ordinary skill in the art and that the compound of Schriewer would have reasonably been selected as a lead compound. The case law of our reviewing court has consistently held that a simple substitution in an otherwise obvious prior art molecule is insufficient to render the molecule nonobvious. See, e.g., In re Dillon, 919 F.2d 688, 696 (Fed. Cir. 1990) ; see also In re Shetty, 566 F.2d 81, 85-86 (C.C.P.A. 1977) (concluding that "the difference of a mere methylene group between the compound of the claim and the prior art compounds" is obvious); In re Bowers, 359 F.2d 886, 887 (C.C.P.A. 1966).
We note that this case also differs from Takeda because in Takeda there was substantial evidence presented that the claimed compound "pioglitazone exhibited unexpectedly superior properties over the prior art compound b." Takeda, 492 F.3d at 1361. There is no such evidence of unexpected results, or indeed of any results, present in the instant application comparing the claimed composition with Schriewer's disclosed compound. This analysis is consistent with Wilder, where the court found that "one who claims a compound, per se, which is structurally similar to a prior art compound must rebut the presumed expectation that the structurally similar compounds have similar properties." In re Wilder, 563 F.2d 457, 460 (CCP A 1977).
Furthermore we are not persuaded by Appellants' argument that: "the compound of Schriewer MUST include an alkyl substituted piperazine ring to have the activity of the copied Ofloxacin." App. Br. 9-10, 15. We agree with Appellants that the 4-methyl-substituted piperazine compound described in Schriewer, and depicted supra, corresponds to ofloxacin, which is further described as having antibiotic properties in Examples 4 and 16. However, we decline to read the teachings of Schriewer so narrowly. Rather than being limited to teaching solely a method for the synthesis of ofloxacin, Schriewer is directed to: "a process for the preparation of highly antibacterially-active enantiomerically-pure 1, 8-bridged 4-quinolone-3carboxylic acids and derivatives." Schriewer Abstr. Schriewer is directed to the synthesis of a large genus of compounds, some of which have antibacterial activity. However, Appellants adduce no evidence teaching or...
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