`Trials@uspto.gov
`Date: May 12, 2020
`
`571-272-7822
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`MYLAN PHARMACEUTICALS INC.,
`Petitioner,
`
`v.
`
`MERCK SHARP & DOHME CORP.,
`Patent Owner.
`____________
`
`IPR2020-00040
`Patent 7,326,708 B2
`____________
`
`
`
`Before SHERIDAN K. SNEDDEN, ROBERT A. POLLOCK, and
`TIMOTHY G. MAJORS, Administrative Patent Judges.
`
`MAJORS, Administrative Patent Judge.
`
`
`
`
`DECISION
`Granting Institution of Inter Partes Review
`35 U.S.C. § 314
`
`
`
`
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`IPR2020-00040
`Patent 7,326,708 B2
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`INTRODUCTION
`I.
`Mylan Pharmaceuticals Inc. (“Petitioner” or “Mylan”),1 on October
`30, 2019, filed a Petition to institute inter partes review of claims 1–4, 17,
`19, and 21–23 of U.S. Patent No. 7,326,708 B2 (Ex. 1001, “the ’708
`patent”). Paper 1 (“Pet.” or “Petition”). Merck Sharp & Dohme Corp.
`(“Patent Owner” or “Merck”) filed a Preliminary Response to the Petition.
`Paper 10 (“Prelim. Resp.”).
`We granted (Paper 11) Petitioner’s request to file a pre-institution
`Reply to Patent Owner’s Preliminary Response. Paper 13. We permitted
`Patent Owner to file a Sur-Reply to Petitioner’s authorized Reply. Paper 14.
`We permitted the filing of a Joint Notice of Supplemental Authority so that
`the parties could each address recently designated precedential decisions
`from the Board related to discretionary denials under 35 U.S.C. §§ 314(a) or
`325(d). Paper 15. And, we requested supplemental briefing on the potential
`applicability of the factors set forth in Apple Inc. v. Fintiv, Inc., IPR2020-
`00019, Paper 11 at 5 (PTAB Mar. 20, 2020) (precedential), to § 314(a)
`discretionary denial here. Paper 17 (Order), Paper 18 (Mylan brief);
`Paper 19 (Merck brief).
`Under 35 U.S.C. § 314(a), inter partes review may not be instituted
`unless the Petition “shows that there is a reasonable likelihood that the
`petitioner would prevail with respect to at least 1 of the claims challenged in
`the petition.” For reasons stated below, we determine that Petitioner has
`
`
`1 Petitioner identifies itself, Mylan Inc., and Mylan N.V. as the real parties-
`in-interest. Pet. 6.
`
`2
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`established a reasonable likelihood that it would prevail with respect to at
`least one challenged claim. We do not deny institution on a discretionary
`basis as requested by Patent Owner. We, therefore, institute inter partes
`review of claims 1–4, 17, 19, and 21–23 of the ’708 patent.
`
` Related Patents and Proceedings
`Petitioner states that, based on its search of Patent Office records,
`“there are no related United States patents or pending applications.” Pet. 7.
`Petitioner further states that, “to the best of Petitioner’s knowledge, this is
`the first IPR directed to the ’708 patent.” Pet. 67.
`Petitioner identifies several related cases pending before the courts
`including, without limitation, the following: Merck Sharp & Dohme Corp. v.
`Mylan Pharm. Inc. et al., 1:19:-cv-00101 (N.D. W. Va); Merck Sharp &
`Dohme Corp. v. Mylan Pharm. Inc. et al., 1:19-cv-01489 (D. Del.); and
`Merck Sharp & Dohme Corp. v. Sandoz, Inc., 1:19-cv-00312 (D. Del.).
`Pet. 6–7 (listing cases). As Patent Owner explains, it “has filed Hatch-
`Waxman suits alleging infringement of the ’708 patent, among others,
`against fourteen generic drug companies including Mylan, Teva, Apotex,
`Par, Sun, and Sandoz.” Prelim. Resp. 10. As Patent Owner also notes, the
`litigation against the generic drug companies “has been consolidated for
`pretrial proceedings in a multidistrict litigation (‘MDL’)” before the district
`court in Delaware. Id. (identifying In re Sitagliptin Phosphate (’708 &
`’921) Patent Litig. C.A. No. 19-md-2902-RGA (D. Del.)).
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` Asserted Grounds of Unpatentability
`Petitioner asserts six grounds of unpatentability (Pet. 12) as set forth
`in the table below:
`Claims Challenged
`1–3, 17, 19, 21–23
`
`Basis
`
`WO ’4983
`
`35 U.S.C. §
`102(a),
`102(e)(2)2
`
`102(e)(2)
`
`1–3, 17, 19, 21–23
`
`3, 17, 19, 21–23
`
`1–3, 17, 19, 21–23
`
`4
`
`103
`
`103
`
`103
`
`the ’871 patent4
`
`WO ’498
`
`WO ’498, Bastin5
`
`WO ’498, Bastin, Brittain6
`
`
`2 The Leahy-Smith America Invents Act, Pub. L. No. 112-29, 125 Stat. 284
`(2011) (“AIA”), amended 35 U.S.C. §§ 102 and 103. Because the
`challenged claims of the ’708 Patent have an effective filing date before the
`effective date of the applicable AIA amendments, we refer to the pre-AIA
`versions of 35 U.S.C. §§ 102 and 103 in this Decision.
`3 Edmondson et al., WO 03/004498 A1, published Jan. 16, 2003 (Ex. 1004,
`“WO ’498”). WO ’498 published from Application No. PCT/US02/21349,
`filed July 5, 2002, which claims priority to US Provisional Application No.
`60/303,474, filed July 6, 2001 (Ex. 1012).
`4 Edmondson et al., US 6,699,871 B2, issued Mar. 2, 2004 (Ex. 1007, “the
`’871 patent”). The ’871 patent issued from an application filed July 5, 2002,
`and claims priority to US Provisional Application No. 60/303,474, filed July
`6, 2001 (Ex. 1012).
`5 Richard J. Bastin et al., Salt Selection and Optimisation Procedures for
`Pharmaceutical New Chemical Entities, 4 ORGANIC PROCESS RESEARCH &
`DEVELOPMENT 427–435, 2000 (Ex. 1006, “Bastin”).
`6 Polymorphism in Pharmaceutical Solids, Harry G. Brittain ed., 1999
`(Ex. 1005, “Brittain”).
`
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`Claims Challenged
`4
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`35 U.S.C. §
`103
`
`Basis
`WO ’498, Brittain
`
`Petitioner also relies on the declaration of Mukund Chorghade, Ph.D.
`(Ex. 1002), among other evidence.
`
` The ’708 Patent
`The ’708 patent is titled “PHOSPHORIC ACID SALT OF A
`DIPEPTIDYL PEPTIDASE-IV INHIBITOR.” Ex. 1001, (54).
`According to the ’708 patent, “[t]he present invention relates to a
`particular salt of a dipeptidyl peptidase-IV inhibitor,” and specifically, the
`dihydrogenphosphate (“DHP”) salt of 4-oxo-4-[3-(trifluoromethyl)-5,6-
`dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-
`trifluorophenyl)butan-2-amine. Id. at 1:13–17. The chemical,4-oxo-4-[3-
`(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-
`(2,4,5-trifluorophenyl)butan-2-amine, is also known as “sitagliptin.” See
`Ex. 2003 ¶ 2; Pet. 1 n.1.7 The formula for the DHP salt of sitagliptin is
`shown below as formula (I):
`
`
`7 Petitioner notes that sitagliptin is also known as the chemical: 7-[(3R)-3-
`amino-4-(2,4,5-trifluorophenyl)butanoyl]-3-(trifluoromethyl)-5,6,7,8-
`tetrahydro-1,2,4-triazolo[4,3-α]pyrazine. Pet. 1 n.1; Ex. 1004, 47
`(Example 7); Ex. 1007, 32:1–16 (Example 7); Ex. 1002 ¶ 67 (discussing
`Example 7 of WO ’498 as “the hydrochloride salt of sitagliptin in its (R)-
`configuration”). In citing to the asserted references and other exhibits in this
`Decision, we use the pagination added to the exhibit copies not the original
`pagination, except that, for US patents, we use the column and line format or
`other indicia in such patents.
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`Ex. 1001, 2:44–63. This formula reflects a salt with one equivalent of the
`phosphate anion associated with one equivalent of sitagliptin amine cation
`(with a stereogenic carbon at *). Id. at 2:66–3:3 (“all isomeric forms being
`included”), 3:46–52 (“[T]he dihydrogenphosphate salt of the present
`invention is comprised of one molar equivalent of mono-protonated
`[sitagliptin] . . . and one molar equivalent of the dihydrogenphosphate
`(biphosphate) anion.”); Ex. 2002 ¶ 19 (depicting the apparent reaction of
`sitagliptin with phosphoric acid to form the DHP salt).
`The ’708 patent states that this salt of sitagliptin is “useful for the
`treatment and prevention of diseases and conditions for which an inhibitor of
`dipeptidyl peptidase-IV is indicated, in particular Type 2 diabetes.”
`Ex. 1001, 1:19–22.
`In a section related to background of the invention, the ’708 patent
`identifies WO 03/004498 (i.e., WO ’498, asserted here), which the patent
`states is “assigned to Merck & Co.” Id. at 1:49–50. The ’708 patent states
`that WO ’498 “describes a class of beta-amino tetrahydrotriazolo[4,3-
`a]pyrazines, which are potent inhibitors of DP-IV and therefore useful for
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`the treatment of Type 2 diabetes.” Id. at 1:50–52. According to the ’708
`patent, WO ’498 “[s]pecifically disclose[s]” the 4-oxo-4-[3-
`(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl]-1-
`(2,4,5-trifluorophenyl)butan-2-amine. Id. at 1:53–55. The ’708 patent states
`that “[p]harmaceutically acceptable salts of this compound are generically
`encompassed within the scope of WO 03/004498.” Id. at 1:53–57.
`“However,” the ’708 patent states, “there is no specific disclosure in the
`above reference [(WO ’498)] of the newly discovered monobasic
`dihydrogenphosphate salt . . . of structural formula I.” Id. at 1:58–62.
`
` Challenged Claims
`The ’708 patent includes twenty-four claims. Claims 1, 2, and 19 are
`illustrative of the claims challenged by Petitioner and read as follows:
`1. A dihydrogenphosphate salt of 4-oxo-4-[3-(trifluoromethyl)-
`5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl]-1-(2,4,5-
`trifluorophenyl)butan-2-amine of structural formula I:
`
`
`or a hydrate thereof.
`
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`2. The salt of claim 1 of structural formula II having the (R)-
`configuration at the chiral center marked with an *
`
`
`19. A method for the treatment of type 2 diabetes comprising
`administering to a patient in need of such treatment a
`therapeutically effective amount of the salt according to claim 2
`or a hydrate thereof.
`Ex. 1001, 15:64–16:30, 17:29–32.
`
` Prosecution History
`The ’708 patent issued from a utility application filed June 23, 2004,
`which claims priority to a provisional application filed June 24, 2003.
`Ex. 1001, (21), (22), (60); Ex. 1010 (prosecution history), passim. The
`utility application as filed included 35 claims. Ex. 1010, 22–24. Shortly
`after the application was filed, applicants submitted an Information
`Disclosure Statement (“IDS”) that identified WO ’498, the ’871 patent, and
`one other reference. Ex. 1010, 44–46 (IDS dated Sept. 13, 2004).
`In an Office Action dated June 11, 2007, the Examiner rejected then-
`pending claims 31 and 32 under 35 U.S.C. § 101 for claiming a method
`without any recited steps. Ex. 1010, 146–149. The Examiner rejected
`
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`claims 25 and 26 under 35 U.S.C. § 112, first paragraph, for failing to enable
`the then-recited “solvate[s].” Id. at 149–152. And, the Examiner rejected
`claims 17–24 under 35 U.S.C. § 112, second paragraph, for indefiniteness
`based on what the Examiner considered an improper transitional phrase. Id.
`at 153. In the same Office Action, the Examiner provisionally rejected
`claims 1–28 and 33–34 for nonstatutory obviousness-type double patenting
`over claims in two co-pending applications (US Appl. Nos. 10/569,566 and
`10/570,409). Id. at 153–155. The Examiner indicated that claims 29, 30,
`and 35 (issued claims 21, 22, and 24) were allowed. Id. at 147.
`Applicants and the Examiner participated in an interview on July 24,
`2007, which was followed by applicants’ written response on August 6,
`2007. Id. at 230–232 (Interview Summary), 233–243 (Amendment and
`Remarks). In that response, applicants amended several claims and canceled
`claims 24 and 31–33, which applicants asserted obviated the rejections under
`§§ 101 and 112. Id. at 240–241. On double patenting, applicants pointed to
`the cancellation, withdrawal, and/or amendment of claims in the co-pending
`applications, and argued that the present claims were distinct from the
`claims of those other applications, as modified. Id. at 241–242.
`On November 5, 2007, the Examiner entered a Notice of Allowability
`and Examiner’s Amendment8 with no substantive comment or express
`reasons given for allowing the claims. Id. at 245–250.
`
`
`8 The Examiner’s Amendment cancelled claims 17–23 and Examiner
`indicated that authorization for cancelling those claims was provided in a
`telephone interview. Ex. 1010, 249.
`
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`II. DISCRETION UNDER 35 U.S.C. § 325(d)
` Legal Principles
`Institution of inter partes review is discretionary. Harmonic Inc. v.
`Avid Tech., Inc., 815 F.3d 1356, 1367 (Fed. Cir. 2016) (explaining that “the
`PTO is permitted, but never compelled, to institute an IPR proceeding”).
`The Patent Office may, for example, deny institution under 35 U.S.C.
`§ 325(d), which provides, in pertinent part, that “[i]n determining whether to
`institute or order a proceeding under this chapter . . . the Director may take
`into account whether, and reject the petition or request because, the same or
`substantially the same prior art or arguments previously were presented to
`the Office.”
`In evaluating whether the same or substantially the same prior art or
`arguments were previously presented to the Office, the Board has identified
`several non-exclusive factors that may be considered. Becton, Dickinson &
`Co. v. B. Braun Melsungen AG, Case IPR2017-01586, Paper 8 at 17–18
`(PTAB Dec. 15, 2017) (precedential as to § III.C.5, first paragraph) (“the
`Becton, Dickinson factors”). Those factors are as follows:
`(a) the similarities and material differences between the asserted
`art and the prior art involved during examination;
`(b) the cumulative nature of the asserted art and the prior art
`evaluated during examination;
`(c) the extent to which the asserted art was evaluated during
`examination, including whether the prior art was the basis for
`rejection;
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`(d) the extent of the overlap between the arguments made during
`examination and the manner in which Petitioner relies on the
`prior art or Patent Owner distinguishes the prior art;
`(e) whether Petitioner has pointed out sufficiently how the
`Examiner erred in its evaluation of the asserted prior art; and
`(f) the extent to which additional evidence and facts presented in
`the Petition warrant reconsideration of prior art or arguments.
`Id.; see also Office Patent Trial Practice Guide Update (“Trial Practice
`Guide Update”), referenced at 83 Fed. Reg. 39,989 (Aug. 13, 2018), at 12
`(citing the Becton, Dickinson factors).
`As more recently explained in Advanced Bionics, LLC v. Med-El
`Electromedizinishe Gerӓte GMBH, IPR2019-01469, Paper 6 at 8–10 (Feb.
`13, 2020) (“Advanced Bionics”) (precedential), the Board addresses § 325(d)
`applying a “two-part framework.” In the first part of the framework, we ask
`whether the same or substantially the same art previously was presented to
`the Office or whether the same or substantially the same arguments
`previously were presented to the Office. Advanced Bionics at 8. Factors (a),
`(b), and (d) of Becton, Dickinson come into play under this first part of the
`framework. Id. at 8–10. If either condition of the framework’s first part is
`met (e.g., substantially the same art is presented), we move to part two of the
`framework, asking “whether the petitioner has demonstrated that the Office
`erred in a manner material to the patentability of [the] challenged claims.”
`Id. at 8. Factors (c), (e), and (f) of Becton, Dickinson fall within part two of
`the framework. Id. at 10 (“[F]actors (c), (e), and (f) relate to whether the
`petitioner has demonstrated material error by the Office.”).
`
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`Only if the same or substantially the same art or arguments were
`previously presented to the Office do we then consider whether petitioner
`has demonstrated error. Advanced Bionics at 8–10. “If the petitioner fails to
`show that the Office erred, the Director may exercise his discretion not to
`institute inter partes review.” Id. at 8–9. “At bottom, this [§ 325(d)]
`framework reflects a commitment to defer to previous Office evaluations of
`the evidence of record unless material error is shown.” Id. at 9 (“If
`reasonable minds can disagree regarding the purported treatment of the art or
`arguments, it cannot be said that the Office erred in a manner material to
`patentability.”).
`
` The Parties’ § 325(d) Arguments
`Petitioner argues that the Board should not deny the Petition under
`§ 325(d) because “the Examiner raised no prior art rejections” and “the
`arguments presented in this Petition are necessarily different” than during
`prosecution. Pet. 66. Moreover, even if some of the references asserted here
`were disclosed to the Examiner, but not applied in a rejection, Petitioner
`contends the Board has declined to exercise § 325(d) discretion under such
`circumstances. Id. at 66–67 (citing Amgen Inc. v. Alexion Pharm. Inc.,
`IPR2019-00740, Paper 15 at 65 (PTAB Aug. 20, 2019)).
`In additional briefing, Petitioner reiterates that no prior art rejection
`was made during prosecution and urges that an examiner’s “[p]resumptive
`awareness” of the prior art does not support § 325(d) denial. Paper 13, 1–2
`(flagging that the Examiner did not “initial the listing of WO ’498 on the
`IDS”). To the extent WO ’498 was identified in the specification itself,
`Petitioner describes this as a “short” and “hurried account” of the reference.
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`Id. at 2–3 (“Merck does not cite a single decision where the PTAB denied a
`petition on the basis of §325(d) because a reference was disclosed to the
`Examiner on an IDS and discussed in the specification, but not applied
`during Examination.”).
`In any event, Petitioner contends that it has identified additional facts
`and evidence that go beyond the account of WO ’498 in the specification.
`For example, Petitioner cites the “75 page declaration by its expert,
`Dr. Chorghade” explaining, among other things, the significance of
`WO ’498’s express disclosure of a “[p]articularly preferred” phosphoric acid
`salt. Id. at 4–5; Ex. 1004, 11:8–15. Further to this point, Petitioner contends
`it has shown that the Examiner overlooked something persuasive as to
`WO ’498 and, thus, has demonstrated the Office erred. Paper 15, App’x A.
`Also, Petitioner notes that it relies on “additional art,” specifically Bastin
`and Brittain, which was not cited to the Office previously. Paper 13, 5.
`Patent Owner argues that Petitioner’s challenge rehashes the same art
`and arguments already presented to the Office. Prelim. Resp. 13–14. Patent
`Owner contends that Petitioner relies primarily on WO ’498, but that
`reference was cited in an IDS9 and discussed on the first page of the
`specification of the application as filed. Id. at 14, 16–17. According to
`Patent Owner, nothing in § 325(d) requires a rejection over the cited art. Id.
`at 19–21; Paper 14, 4; Paper 15, App’x B. Patent Owner contends that
`Petitioner’s argument overlaps with the specification’s discussion of
`
`9 Patent Owner also contends Petitioner’s reliance on the US counterpart to
`WO ’498 (the ’871 patent) does not raise any meaningfully different issues,
`and that the ’871 patent was also cited to the Examiner. Prelim. Resp. 14.
`13
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`WO ’498, which the Examiner must have considered yet deemed meritless.
`Prelim. Resp. 16–19. On Bastin and Brittain, Patent Owner contends that
`those references are more generic in their teachings than WO ’498 (and the
`’871 patent), with no specific relation to sitagliptin, and thus are
`“cumulative.” Prelim. Resp. 15–16. Also, Patent Owner contends, there is
`neither a showing of error nor additional facts that warrant reconsideration
`of the prior art or arguments. Id. at 18–19; Paper 14, 4–5.
` § 325(d) Framework: Part One
`We conclude that the prior art relied upon by Petitioner here is
`substantially the same as prior art previously presented to the Examiner.
`There is no dispute that WO ’498 and the ’871 patent were identified in an
`IDS early in prosecution, and that the Examiner later signed that IDS.
`Ex. 1010, 46, 157.10 The absence of the Examiner’s initials next to
`WO ’498 is not a significant consideration on this record because, as the
`parties acknowledge, the disclosure of WO ’498 and the ’871 patent are
`essentially the same. Pet. 33; Prelim. Resp. 17. And, the Examiner’s initials
`are added next to the ’871 patent on the IDS. Ex. 1010, 157.
`As Patent Owner notes, a rejection over a prior art reference that is
`later relied upon in an IPR petition is not necessary to show that such art was
`previously presented to the Office. Paper 15, App’x B; Paper 14, 4. To the
`contrary, “previously presented art includes art made of record by Examiner,
`and art provided to the Office by an applicant, such as on an Information
`
`
`10 There were a relatively small number of total references cited during
`prosecution (a total of seven). Ex. 1001, (56).
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`Disclosure Statement (IDS), in the prosecution history of the challenged
`patent.” Advanced Bionics at 7–8 (emphasis added). Petitioner’s emphasis
`on the absence of any prior art rejection as if dispositive on the § 325(d)
`inquiry is, thus, misplaced; the first part of the § 325(d) framework may be
`met when relied-upon art is presented in an IDS but never discussed or cited
`in a rejection by the Examiner—as was the case here with WO ’498 and the
`’871 patent.
`Bastin was not presented during prosecution. But Bastin’s cited
`teachings are, on balance, cumulative to the listing of phosphoric acid salts
`in WO ’498 and the ’871 patent—both of which provide specific disclosures
`related to sitagliptin, whereas Bastin is not.
`Bastin describes a number of general considerations when forming
`pharmaceutical salts. See, e.g., Ex. 1006, 2 (“[T]he choice of salt is
`governed largely by the acidity or basicity of the ionisable group, [and]
`safety of the counterion”). For example, Bastin discloses that “[f]or weakly
`basic drug substances, salts of an inorganic acid (e.g., hydrochloride,
`sulphate, or phosphate) . . . could be considered.” Id. (Table 1, listing
`“common pharmaceutical salts” including those with hydrochloride or
`phosphate anions). WO ’498, on the other hand, exemplifies sitagliptin
`hydrochloride (Ex. 1004, 47 (Example 7)), and describes and claims (R)-
`sitagliptin and “pharmaceutically acceptable salts thereof,” which include
`the phosphoric acid salt. Ex. 1004, 55–61, 11:8–15 (identifying
`“[p]articularly preferred . . . citric, hydrobromic, hydrochloric, maleic,
`phosphoric, sulfuric, fumaric, and tartaric acids”). Hence, WO ’498 includes
`substantially the same disclosures as Bastin insofar as both identify
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`phosphoric acid salts as suitable or preferred salt forms. (Indeed, WO ’498’s
`teachings are more precisely on point relative to claimed subject matter as
`WO ’498’s teachings are connected to sitagliptin).
`Brittain was not cited during prosecution. Petitioner’s reliance on
`Brittain is, however, minimal. Petitioner cites Brittain only in combination
`with WO ’498 (or WO ’498 combined with Bastin) and only to address the
`alleged obviousness of dependent claim 4. See, e.g., Pet. 61–62 (asserting
`that WO ’498 discloses forming hydrates of the compounds and, based on
`Brittain’s teaching that monohydrates are the “most frequently encountered”
`variant, it would have been obvious to form a “crystalline monohydrate” as
`in claim 4); Ex. 1005, 6. None of Petitioner’s arguments on discretionary
`denial point to any material teaching in Brittain. Petitioner’s passing
`characterization of Brittain as “additional art” weighs little in determining
`whether the first part of the § 325(d) framework is met. Paper 13, 4;
`Microsoft Corp. v. IPA Technologies Inc., IPR2019-00839, Paper 9 at 15
`(PTAB Nov. 8, 2019) (holding, in § 325(d) analysis, that little weight is due
`references that are “not relied upon heavily in the Petition (i.e., . . . solely for
`additional limitations of several dependent claims)”).
`For the above reasons, we conclude that substantially the same prior
`art that Petitioner relies upon was previously presented to the Examiner
`during prosecution. The first part of the § 325(d) framework is, therefore,
`met, and we turn to whether error by the Office has been shown. See
`Advanced Bionics at 8.
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` § 325(d) Framework: Part Two
`Even accepting that WO ’498 was presented to the Examiner, we
`conclude that a material error occurred during prosecution. Material error
`may include, for example, an examiner “misapprehending or overlooking
`specific teachings of the relevant prior art where those teachings impact
`patentability of the challenged claims.” Advanced Bionics at 8 n.9.
`Petitioner has shown that WO ’498 (as well as the ’871 patent)
`describes and claims sitagliptin and pharmaceutically acceptable salts
`thereof. See, e.g., Ex. 1004, 55–61 (claim 15, (R)-sitagliptin depicted as the
`bottom compound on p. 56); see also Ex. 1007, 41:1–15 (claim 17, chemical
`formula for (R)-sitagliptin “or a pharmaceutically acceptable salt thereof”);
`see also Ex. 1004, 47 (working example of the 1:1 sitagliptin hydrochloride
`salt). That, however, is not the end of WO ’498’s relevant teachings.
`WO ’498 defines “pharmaceutically acceptable salts” as including “salts
`prepared from pharmaceutically acceptable non-toxic bases or acids
`including . . . inorganic or organic acids.” Ex. 1004, 10:27–29; see also id.
`at 11:16–17 (“It will be understood that, as used herein, references to the
`compounds of Formula I are meant to also include the pharmaceutically
`acceptable salts”). WO ’498 immediately goes on to disclose that “[w]hen
`the compound of the present invention is basic [i.e., like sitagliptin], salts
`may be prepared from pharmaceutically acceptable non-toxic acids”—eight
`of which are listed as “[p]articularly preferred” acids. Id. at 11:8–15.11
`
`
`11 As Dr. Chorghade explains, “the POSA would have known the
`
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`And, of significance here, one of those eight “particularly preferred” acids is
`“phosphoric” acid. Id. at 11:14–15 (listing, inter alia, hydrochloric and
`phosphoric, and sulfuric acids); see also Ex. 1007, 6:61–7:7 (defining the
`pharmaceutically acceptable salts as including phosphoric acid salts). Based
`on the present record, Petitioner has shown to a reasonable likelihood that
`the phosphoric acid salt of sitagliptin is the invention claimed. Ex. 1002
`¶ 75 (“Claim 1 refers to ‘dihydrogenphosphate salt’ of sitagliptin, [yet] this
`is nothing more than another name for the phosphoric acid salt of
`sitagliptin”).12
`The Examiner never discussed WO ’498 or made a rejection based on
`it. Indeed, the Examiner entered no prior art rejection against the claims of
`the ’708 patent. See supra Section I(E). Because the Examiner gave no
`reasons for allowance, we are left to guess at why the Examiner regarded the
`’708 patent’s claims as novel and nonobvious.
`We conclude on the existing record, however, that reasonable minds
`cannot disagree that WO ’498 describes the phosphoric acid salt of
`sitagliptin and this disclosure meets the claimed invention. The likeliest
`explanation, on this record, for the lack of a prima facie rejection for
`anticipation or obviousness is that the Examiner simply overlooked
`WO ’498’s teaching of sitagliptin and a “particularly preferred” phosphoric
`
`
`compounds of Examples 1-7 are basic due to the presence of the NH2
`(amino) group.” Ex. 1002, ¶¶ 146–147; Ex. 1016, 616–617; Ex. 1004, 47
`(Example 7 is sitagliptin).
`12 We address in more detail below Patent Owner’s contention that the 1:1
`ratio is not expressly described in WO ’498. Infra Section V(D)(2).
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`acid salt form. Patent Owner now argues that it reduced to practice the
`subject matter of certain claims before the § 102(a) publication date of
`WO ’498, and that WO ’498 cannot, thus, be used to show obviousness
`because it was and is commonly owned by Merck. Prelim. Resp. 32–33
`(citing an exception under § 103(c)). But there is no indication that the
`Examiner knew of this argument during prosecution, such that it might have
`explained the lack of a § 102(a) or § 103 rejection over WO ’498. Also,
`Merck emphasizes that it disclosed in the specification that
`“[p]harmaceutically acceptable salts of this compound [(sitagliptin)] are
`generically encompassed within the scope” of WO ’498. Prelim. Resp. 1–2,
`6. Yet WO ’498’s teachings are not as vague or limited as this statement in
`the specification suggests. As Petitioner notes, “at no point does [the
`specification] state that WO ’498 contains a small ‘[p]articularly preferred’
`list of the salts—one of which is the phosphoric acid salt.” Paper 13, 4–5.13
`By not citing such teachings in WO ’498, we find “the Examiner erred in the
`evaluation of the prior art . . . [and] overlooked specific teachings in the
`relevant prior art such that error by the Office was material to the
`patentability of the challenged claims.” Advanced Bionics at 21.
`
`
`13 Petitioner also contends that attempts by Merck to argue the specific
`phosphoric acid salt of sitagliptin is not described in WO ’498 (or the ’871
`patent counterpart) are undermined by Merck’s listing of the ’871 and ’708
`patents in the FDA Orange Book for Januvia®. Pet. 5; Ex. 1009 (identifying
`the ’871 and ’708 patents as each claiming the drug substance and drug
`product); Ex. 1014, 10 (prescribing information for Januvia® (sitagliptin
`phosphate), describing the product as including “sitagliptin phosphate
`monohydrate” with the formula C16H15F6N5O•H3PO4•H2O). Ex. 1014, 9.
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`The Examiner’s apparent oversight with respect to the highly material
`teachings in WO ’498 (and the ’871 patent), along with Dr. Chorghade’s
`testimony about the significance of those teachings (see, e.g., Ex. 1002
`¶¶ 67–70, 72–80), which was not before the Examiner, convinces us that the
`Office’s reconsideration of the prior art or arguments is justified.
`
`III. DISCRETION UNDER 35 U.S.C. § 314(a)
` Legal Principles
`The Board may also deny institution on a discretionary basis pursuant
`to 35 U.S.C. § 314(a). General Plastic Industrial Co., Ltd. v. Canon
`Kabushiki Kaisha, Case IPR2016-01357, Paper 19 at 8–10, 16–19 (PTAB
`Sept. 6, 2017) (precedential as to § II.B.4.i) (“General Plastic”);14 NHK
`Spring Co. v. Intri-Plex Techs., Inc., IPR2018-00752, Paper 8 (PTAB Sept.
`12, 2018) (precedential) (“NHK”).
`In NHK, the Board exercised its discretion under § 314(a) and denied
`the petition based on, inter alia, the “advanced state” of a related district
`court litigation dealing with overlapping issues. NHK at 20. The Board
`found that instituting inter partes review in that case “would be an
`
`
`14 As this case does not involve multiple, follow-on petitions challenging the
`same patent, some of the factors (i.e., factors 2, 3, 4 and 5) spelled out in
`General Plastic are inapplicable. Pet. 67 (noting that the Petition is the first
`challenge to the ’708 patent’s claims before the Office). General Plastic
`does, in any event, recognize that “an objective of the AIA . . . is to provide
`an effective and efficient alternative to district court litigation,” “to improve
`patent quality,” and notes, inter alia, “the finite resources of the Board” as a
`factor that may be considered when determining if discretionary denial
`under § 314(a) is appropriate. General Plastic at 8–10, 16–19.
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`inefficient use of Board resources” as the same prior art and arguments were
`before the court, and because the litigation was “nearing its final stages”
`with trial before the court set to conclude about six months before the Board
`was projected to reach a final written decision. Id.
`More recently, the Board has explained that “cases addressing earlier
`trial dates as a basis for denial under NHK have sought to balance
`considerations such as system efficiency, fairness, and patent quality.”
`Apple