Dr. Reddy's Laboratories, Inc. v. Merck Sharp & Dohme Corp.

I'll research this case. Note upfront: the metadata identifies this as an IPR at the PTAB, not a district court infringement action, so I'll verify precisely what this proceeding is and how it relates to the parallel litigation.

Good — the IPR picture is clear. Now let me verify the district court litigation, the Federal Circuit outcome, and market context.

Now let me verify the district court outcomes, settlement posture, and market/pricing context.

Case overview and background

A threshold correction: this docket is not an infringement suit. IPR2020-01060, captioned [Dr. Reddy's Laboratories, Inc.](/litigations/by-plaintiff/Dr.%20Reddy's%20Laboratories%2C%20Inc.) v. Merck Sharp & Dohme Corp., is an inter partes review petition filed at the PTAB on June 11, 2020, not a district court action. Both parties here are operating pharmaceutical companies: Dr. Reddy's Laboratories (Hyderabad-based generics manufacturer; real parties-in-interest listed as Dr. Reddy's Laboratories, Inc. and Dr. Reddy's Laboratories, Ltd.) is the petitioner, and Merck Sharp & Dohme — the innovator arm of Merck & Co. that markets Januvia®, Janumet® and Janumet XR® — is the patent owner. The single patent at issue is U.S. Pat. No. 7,326,708, "Phosphoric acid salt of a dipeptidyl peptidase-IV inhibitor" (Cypes et al., issued Feb. 5, 2008). In one line: the '708 patent claims the 1:1 dihydrogenphosphate ("DHP") salt of sitagliptin — the specific salt form of Merck's DPP-IV inhibitor used in its Type 2 diabetes products — including its (R)- and (S)-stereoisomers (claims 2–3) and the crystalline monohydrate (claim 4). There is no NPE/PAE or university dimension to this case; it is a pure Hatch-Waxman/ANDA-driven validity fight between an innovator and a generic, litigated simultaneously at the PTAB and in the district courts.

What DRL actually challenged, and why the docket is described as "joinder." DRL's petition challenged claims 1–4, 17, 19 and 21–23 on six grounds: (1)–(2) anticipation under pre-AIA § 102 by Merck's own earlier WO 03/004498 publication and its U.S. counterpart U.S. Pat. No. 6,699,871 (together "Edmondson"); and (3)–(6) obviousness over WO '498 alone and in combinations with Bastin (salt selection) and Brittain (polymorphism/hydrates). The petition was expressly a "me-too" petition — substantially identical to Mylan's earlier-filed IPR2020-00040 (filed Oct. 30, 2019; instituted May 12, 2020 on the same claims and grounds). On September 1, 2020, the Board (Judges Snedden, Pollock and Majors) instituted review and granted DRL's motion for joinder under 35 U.S.C. § 315(c), conditioning DRL's participation on a "true and silent understudy" role: DRL agreed to raise no new grounds, file no substantive papers, rely on and be bound by Mylan's expert (Dr. Mukund Chorghade), and withdraw its own expert declaration. See IPR2020-01060, Paper 15. Parallel me-too petitions by Teva/Watson (IPR2020-01045) and Sun (IPR2020-01072) were handled the same way. DRL's counsel were Lerner David (Faegenburg, Van Buskirk, Teschner) and Katten Muchin Rosenman (Malik, Pacchioli, West, Radeke); Merck was represented by Williams & Connolly (Fisher, Berniker, Mahaffy, Sheh).

Procedural posture and outcome — the real "venue" story is Delaware. Because the IPR was joined to the Mylan IPR, all further filings occurred in IPR2020-00040, and the Board's Final Written Decision of May 7, 2021 held that no challenged claim was unpatentable — Merck won on both express/inherent anticipation (the Board found WO '498 neither expressly nor inherently discloses the 1:1 sitagliptin DHP salt; "957 salts" is too many to "at once envisage" under In re Petering) and on obviousness (Merck antedated Edmondson by reducing the 1:1 (R)-sitagliptin DHP salt to practice in December 2001, and pre-AIA § 103(c)(1) common ownership knocked out the '871 patent). Mylan Pharms. Inc. v. Merck Sharp & Dohme Corp., No. IPR2020-00040, 2021 WL 1833325 (P.T.A.B. May 7, 2021). The Federal Circuit affirmed in a precedential opinion by Judge Lourie, joined by Judges Reyna and Stoll, on September 29, 2022. Mylan Pharms. Inc. v. Merck Sharp & Dohme Corp., No. 2021-2121 (Fed. Cir. Sept. 29, 2022). IPR2020-01060 itself was terminated on or about May 10, 2021 following the FWD in the joined proceeding, and the caption in IPR2020-00040 was amended to list Mylan, Teva, Watson, DRL and Sun as petitioners. The parallel district court litigation is the far larger proceeding: Merck filed Hatch-Waxman suits against roughly 14 defendant groups (23 defendants) covering 26 ANDAs, consolidated for pretrial proceedings as In re Sitagliptin Phosphate ('708 & '921) Patent Litig., MDL No. 2902, C.A. No. 19-md-2902-RGA (D. Del.) before Judge Richard G. Andrews (J.P.M.L. transfer order, Aug. 8, 2019). Judge Andrews issued the key Markman ruling on November 17, 2020, 2020 WL 6743022, construing "crystalline monohydrate" and the '708 claims, and rejecting the generics' attempt to exclude hydrates from claims 2–3. DRL's own Delaware case was Merck Sharp & Dohme Corp. v. Dr. Reddy's Laboratories Ltd., 1:20-cv-00847 (D. Del.). The lead case went to a five-day bench trial before Judge Irene M. Keeley in the N.D. W. Va. (Merck Sharp & Dohme LLC v. Mylan Pharms. Inc., No. 1:19-cv-00101-IMK), which ruled for Merck on September 21/29, 2022: Mylan's ANDA products infringed claim 3 of the '708 patent and claim 1 of the '921 patent, and Mylan failed to prove invalidity (obviousness-type double patenting, written description, enablement). The accompanying final judgment set ANDA approval dates no earlier than the '708 (and, for Janumet, '921) expiration dates.

Why it matters. (1) Commercial stakes: the '708 patent is the salt-form patent that gates generic sitagliptin — it expires November 24, 2026 (March 24, 2027 with pediatric exclusivity), while the earlier genus/compound patent, U.S. Pat. No. 6,699,871, expired July 26, 2022 (Jan. 26, 2023 with pediatric exclusivity), and the Janumet-composition '921 patent runs to 2028/2029. The Januvia/Janumet franchise has been one of Merck's largest-selling product families, so the '708 patent effectively preserved exclusivity for years beyond compound-patent expiry. (2) IPR linkage: IPR2020-01060 is a textbook illustration of the "me-too" joinder pattern — co-defendants in a consolidated Hatch-Waxman MDL filing copycat petitions within one month of institution to preserve § 315(b) rights and estoppel positioning while ceding control to a lead petitioner. (3) Legal significance: the Federal Circuit's affirmance produced widely cited guidance on the "at once envisage" doctrine — a class of ~957 theoretical salts is too large to anticipate a single species — and on antedation and the pre-AIA § 103(c)(1) common-ownership exception where the innovator's own earlier application is the asserted prior art. (4) A collateral wrinkle: in the joined proceeding Merck sought a certificate of correction for unchallenged claims 5–7, which the district court had found indefinite because they recited XRPD "absorption bands" rather than "diffraction peaks"; the Board granted leave (IPR2020-00040, Paper 76), noting the merits were for the Director under 35 U.S.C. § 255.

Sourcing caveats: I verified the parties, petition, grounds, institution/joinder order, FWD, Federal Circuit affirmance, MDL number and judge, Markman citation, and the N.D. W. Va. trial outcome from PTAB papers, the Federal Circuit opinion (via mololamken.com, patentdocs.org, IPWatchdog), RPX Insight, Docket Alarm and the district court opinion. I could not verify in this session: specific dollar sales figures for Januvia/Janumet in any given year; the exact disposition of DRL's Delaware case (1:20-cv-00847) or whether DRL settled and obtained a licensed generic entry date; or which of the 14 defendant groups entered consent judgments. Those should be confirmed against PACER/Orange Book before being relied on.

I'll research this case across PTAB, district court, and Federal Circuit sources. Let me start with a broad sweep.

I have the core PTAB picture. Now let me research the underlying district court litigation, the MDL, settlements, and the appeals.

Framing note before the chronology

The case metadata describes IPR2020‑01060 — that docket is not a patent infringement lawsuit. It is an inter partes review petition filed at the PTAB by Dr. Reddy's and a motion to be joined as a party to an already-instituted IPR (IPR2020‑00040, filed by Mylan). There is therefore no complaint, answer, counterclaim, Markman order, verdict, or JMOL on this docket. Those events occurred in the parallel Hatch‑Waxman litigation that the IPRs were designed to influence — principally In re Sitagliptin Phosphate ('708 & '921) Patent Litig., No. 19‑md‑02902‑RGA (D. Del.) (Judge Richard G. Andrews), which includes the Merck v. Dr. Reddy's case, and Merck Sharp & Dohme LLC v. Mylan Pharms. Inc., No. 1:19‑cv‑00101‑IMK (N.D. W. Va.) (Judge Irene Keeley).

Below I cover the PTAB case first (since that is the captioned matter), then the infringement litigation that supplies the complaint/answer/Markman/trial events you asked about. I flag where I could not verify something.

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I. The captioned proceeding — IPR2020‑01060 (Dr. Reddy's v. Merck)

Patent at issue: U.S. 7,326,708 B2, Phosphoric Acid Salt of a Dipeptidyl Peptidase‑IV Inhibitor (Cypes et al.), issued 2008‑02‑05, owned by Merck; claims the 1:1 sitagliptin dihydrogenphosphate (DHP) salt, its (R)- and (S)- configurations (claims 2–3), and the crystalline monohydrate (claim 4). It is the salt patent for JANUVIA / JANUMET / JANUMET XR. Expiry: 2026‑11‑24, pediatric exclusivity to 2027‑05‑24 (Merck press release, 2022‑09‑22

I'll research the counsel of record for the petitioner in this IPR proceeding.

Now let me verify the attorneys' backgrounds and check for any later filings or appearances.

Counsel of Record — Petitioner Dr. Reddy's Laboratories, Inc. & Dr. Reddy's Laboratories, Ltd.

Important framing note: IPR2020-01060 is not a district-court infringement suit but an inter partes review petition filed by Dr. Reddy's (DRL) against Merck before the PTAB. The "plaintiff"/asserting party here is the Petitioner, Dr. Reddy's, and the "counsel of record" are the practitioners designated in DRL's Power of Attorney (Paper 4, filed with the June 11, 2020 Petition) and its Updated Mandatory Notice under 37 C.F.R. § 42.8(a)(3) (Paper 12, July 30, 2020). All three are at a single firm — there is no separate "local counsel" role in PTAB practice (no pro hac vice is required for registered practitioners).

Lead Counsel

Russell W. Faegenburg — Lead Counsel

• Firm / office: Lerner, David, Littenberg, Krumholz & Mentlik, LLP (now "Lerner David LLP"), 20 Commerce Drive, Cranford, NJ 07016 (firm formerly headquartered at 600 South Avenue West, Westfield, NJ).
• PTAB Reg. No. 77,876; admitted NY (1995) and NJ (2003); J.D., Harvard Law School (1994); admitted to the Federal Circuit and D.N.J./S.D.N.Y./E.D.N.Y./W.D.N.Y.
• Note: Firm's lead IPR litigator for the ANDA/Hatch-Waxman side of the '708 patent dispute; he is also DRL's lead counsel in the parallel district-court action Merck Sharp & Dohme Corp. v. Dr. Reddy's Laboratories, Inc., No. 1:20-cv-00847 (D. Del.), admitted pro hac vice on July 27, 2020 (D.I. 10). Prior PTAB/litigation experience includes representing LG Chem in Ube Maxell v. LG Chem, IPR2013-00470 (PTAB denied institution of all asserted grounds), Google in the Space Data IPRs (IPR2018-00944/945/946/947), and Hatch-Waxman defense work for DRL in Helsinn Healthcare v. Dr. Reddy's Labs (D.N.J.).

First Backup Counsel

Tedd W. Van Buskirk — First Backup Counsel

• Firm / office: Lerner David LLP, 20 Commerce Drive (4th Fl.), Cranford, NJ 07016.
• PTAB Reg. No. 46,282; NJ (1995) / NY (1996); J.D., New York Law School (1995); registered patent attorney.
• Note: Long-time Lerner David pharmaceutical/ANDA litigation partner; also admitted pro hac vice for DRL in the parallel Delaware action (D.I. 10, July 2020). Experience includes Amneal's IPR challenges to U.S. Pat. 9,060,976 (IPR2016-01027/01028) and the Sunshine Lake Pharma/HEC Pharm Federal Circuit appeal (No. 20-2229, argued by colleague P. Kochanski; Van Buskirk on the brief).

Backup Counsel

Michael H. Teschner — Backup Counsel

• Firm / office: Lerner David LLP, 20 Commerce Drive, Cranford, NJ 07016.
• PTAB Reg. No. 32,862; NJ (1989); J.D., George Washington University National Law Center (1989); registered patent attorney with a chemistry background.
• Note: Senior IPR practitioner and Lerner David partner; lead counsel for LG Chem in Ube Maxell v. LG Chem, IPR2013-00470, and for St. Jude Medical in its successful IPR invalidating a University of Michigan heart-valve patent; recognized in IAM Patent 1000 (2021) for prosecution and post-grant work.

Contacts / service

The mandatory notice lists service at rfaegenburg.ipr@ldlkm.com, tvanbuskirk@lernerdavid.com, and MTeschner.ipr@ldlkm.com, with the firm's general litigation address litigation@lernerdavid.com.

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Caveats and sourcing

• These three names are confirmed by the Certificate of Service in Patent Owner Merck's Power of Attorney (Paper 6, July 1, 2020) and the Board's institution decision, both of which identify only Faegenburg, Van Buskirk and Teschner as DRL's attorneys of record in IPR2020-01060.
• No change-of-counsel or updated mandatory notice after July 30, 2020 was located. The proceeding was instituted on September 1, 2020 (Paper 15, granting institution and granting DRL's motion for joinder under § 315(c)), and it terminated on May 10, 2021, when the Board terminated the related joined proceedings following settlement of the lead Mylan IPR2020-00040; DRL remained a joined party until that termination. So the Lerner David team above is the complete counsel roster for this case's life.
• Names deliberately excluded: an internal July 2020 email in the joinder correspondence (Ex. 2037) is copied to "Pacchioli, Alissa M.," "Wong, Jovial," "Fischer, Sarah," and "Zullow, Keith A." These are counsel for the other joinder petitioners (Teva / Sun) or Mylan, not DRL counsel, and must not be attributed to Dr. Reddy's. Likewise, the Merck-side attorneys (Williams & Connolly LLP — Stanley E. Fisher, Bruce R. Genderson, Jessamyn S. Berniker, Alexander S. Zolan, Elise M. Baumgarten, Shaun P. Mahaffy, Anthony H. Sheh) are Patent Owner's counsel, not petitioner's.
• Parallel Hatch-Waxman action Merck Sharp & Dohme Corp. v. Dr. Reddy's Laboratories, Inc., No. 1:20-cv-00847 (D. Del.), consolidated into In re Sitagliptin Phosphate ('708 & '921) Patent Litig., MDL No. 19-md-2902-RGA — there DRL's Delaware local counsel was David Moore (Potter Anderson & Corroon LLP), with Faegenburg and Van Buskirk appearing pro hac vice. That local-counsel role exists only in the district court case, not in this IPR.

Would you like me to pull the specific docket entries for the D. Del. action or verify whether any of the three Lerner David attorneys appeared separately in the Mylan IPR after joinder?

I'll research counsel of record for the patent owner (Merck), who occupies the "defendant" role in this IPR, plus verify any co-petitioner/post-joinder counsel appearances.

I have the core PO counsel list. Let me verify attorney details, any additional appearances (Uribe, Krinsky, Zhu), and firm-side bios.

Counsel of Record — "Defendant" (Patent Owner Merck Sharp & Dohme Corp.)

Framing note (consistent with the earlier sections): IPR2020‑01060 is an inter partes review, so the "defendant" side is the Patent Owner, Merck Sharp & Dohme Corp. (a wholly owned subsidiary of Merck & Co., Inc.), not a district‑court defendant. All of Merck's PTAB counsel of record are at a single firm — Williams & Connolly LLP — with no separate "local counsel," since PTAB practice requires no pro hac vice appearance as local counsel (though unregistered attorneys do seek § 42.10(c) pro hac vice admission). Merck's roster is confirmed by Merck's Power of Attorney, Paper 6 (filed July 1, 2020) in IPR2020‑01060 and by the service certificates on DRL's papers (e.g., Petitioners' Updated Mandatory Notice, Paper 12, July 30, 2020).

Standard PTAB service address used by the Merck team: MerckSitagliptin@wc.com.

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Attorneys named in Merck's Power of Attorney (IPR2020‑01060, Paper 6)

Firm address as listed in the 2020 filings: 725 Twelfth Street, N.W., Washington, DC 20005 (T: 202‑434‑5000). Note the firm has since relocated to 680 Maine Avenue, S.W., Washington, DC 20024 (current firm address per W&C and Chambers/IAM profiles) — a change of address, not a change of counsel.

Attorney notes

• Stanley E. Fisher — Lead counsel / first‑chair trial lawyer (Partner). Reg. No. 55,820. B.S. Molecular Biophysics & Biochemistry, Yale (1997); J.D., George Washington University Law School (2004, highest honors). Clerked for Judge Richard Linn, Fed. Cir. Co‑chair of W&C's FDA practice. The American Lawyer named him "Litigator of the Week Runner‑Up" (May 2021) for the Merck sitagliptin IPR win and again (Sept. 2022) for the district‑court trial win. Ranked an IAM Patent 1000 "Leading Patent Litigation Attorney" (2020–2025). wc.com bio
• Jessamyn S. Berniker — Counsel (Partner). Reg. No. 72,328. B.S. Chemistry, Pacific Lutheran (1998); J.D., Harvard (2001); clerked for Judge Arthur Gajarsa, Fed. Cir. Co‑chair of W&C's Patent Litigation practice; Chambers‑ranked for D.C. IP litigation. Deep Hatch‑Waxman/ANDA and PTAB experience (AstraZeneca, Novartis, Alnylam, Pfizer, Merck). wc.com bio
• Bruce R. Genderson — Counsel (Partner, not USPTO‑registered; PHV). Long‑time W&C trial and appellate litigator; part of the core Merck sitagliptin team in both the IPRs and the N.D. W. Va. / D. Del. litigation.
• Alexander S. Zolan — Counsel (Partner; PHV). Appeared for Merck at expert depositions in the joined Mylan IPR and on the Federal Circuit briefing (No. 21‑2121). Litigator with W&C's patent group.
• Elise M. Baumgarten — Counsel (PHV). W&C patent litigator; handled much of the joinder‑related correspondence (e.g., Ex. 2037 emails to the joinder petitioners) and appeared on the Merck sitagliptin trial team.
• Shaun P. Mahaffy — Counsel. Reg. No. 75,534. Was an associate during 2020 (per his email signature in the Merck joinder correspondence); since elevated to partner and named an LMG Life Sciences "Rising Star" (General Patent Litigation, 2025).
• Anthony H. Sheh — Counsel. Reg. No. 70,576. W&C patent litigator on the Merck sitagliptin team.

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Additional W&C attorneys appearing for Merck in the sitagliptin matter

These names surfaced in the joined‑proceeding record, depositions, the Federal Circuit appeal, or W&C's public team announcements — but they were not listed on the IPR2020‑01060 power of attorney, so treat them as the broader Merck team rather than as IPR2020‑01060 counsel of record:

• David Krinsky — W&C partner; appears in IPR2020‑00040 deposition transcripts and on the Fed. Cir. response (No. 21‑2121). Part of Merck's trial/appellate team.
• Sarahi Uribe — W&C associate (joined the firm Sept. 2023 after clerking for Judge Amy Berman Jackson, D.D.C.). Caution/flag: because she joined W&C in 2023 and IPR2020‑01060 terminated in May 2021, she cannot have been counsel of record in this IPR; she appears only in the later district‑court/appeal filings.
• Sahobo Zhu — appeared alongside Zolan at a 2020 deposition in the joined proceeding.

W&C's own post‑trial release lists the sitagliptin district‑court trial team as: Stan Fisher, Bruce Genderson, David Krinsky, Elise Baumgarten, Alexander Zolan, Shaun Mahaffy, Tony Sheh, Sarahi Uribe, Vanessa Omoroghomwan, and Jihad Komis. (wc.com news release) Some of these (Omoroghomwan, Komis) do not appear in any IPR filing and should not be attributed to IPR2020‑01060.

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Sourcing, caveats, and items I could not verify

• Verified: the complete seven‑attorney IPR2020‑01060 power of attorney, the firm and addresses, the service certificate on DRL's July 30, 2020 mandatory notice, and the individual attorney bios (Reg. numbers from the POA; education/clerkships from W&C's own bios).
• Not fully verified: the exact pro hac vice admission orders for Genderson, Zolan, and Baumgarten in this specific IPR. The POA states their PHV motions were "to be submitted"; I did not locate the individual admission orders on IPR2020‑01060's docket in this session. They are plainly admitted in the related proceedings.
• No change/withdrawal of counsel found. The matter terminated ~May 10, 2021 following settlement of the lead Mylan IPR, so the Williams & Connolly roster above is the complete PO‑side counsel list for IPR2020‑01060's life.
• In‑house counsel: I did not identify any named Merck in‑house attorney on the IPR2020‑01060 pleadings; the power of attorney designates only W&C practitioners and Customer No. 129657.
• Correct‑party caution: Do not attribute the petitioner‑side Lerner David attorneys (Faegenburg, Van Buskirk, Teschner) to the defendant side — they represent Dr. Reddy's. Likewise, other W&C names appearing in the MDL (e.g., Dov Grossman, Christopher Mandernach, Tian Huang, Kevin Hoagland‑Hanson, Michael Liu, Adam Harber, Matthew Lachman, Nicholas Jordan) appear in other matters, not IPR2020‑01060.