Litigation

Sun Pharmaceutical Industries Ltd. v. Merck Sharp & Dohme Corp.

joinder

IPR2020-01072

Filed
2020-06-12

Patents at issue (1)

7326708

Summary

Joinder to IPR2020-00040.

Case overview & background

Plain-language overview of the case: parties, accused product, patents at issue, and why the suit matters.

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Case Overview & Background

Parties and their roles. This is a classic Hatch‑Waxman generics‑versus‑innovator fight rather than an NPE/PAE or university assertion. The petitioner, Sun Pharmaceutical Industries Ltd., is a Mumbai‑headquartered multinational generic and specialty drugmaker (with U.S. affiliates including Sun Pharmaceutical Industries, Inc. and Sun Pharma Global FZE) that filed the IPR as an ANDA challenger, not as a patent monetization entity. The patent owner, Merck Sharp & Dohme Corp. (the innovator subsidiary of Merck & Co.; the district‑court captions use "Merck Sharp & Dohme LLC"), is the assignee of U.S. Patent No. 7,326,708 and the maker of the branded sitagliptin products Januvia (sitagliptin phosphate), Janumet, and Janumet XR (J.P.M.L. transfer order, MDL No. 2902, https://www.jpml.uscourts.gov/sites/jpml/files/MDL-2902-Initial_Transfer-07-19.pdf). One notable wrinkle: in India Sun is actually Merck's sitagliptin licensee/marketer (brands Januvia, Janumet, Istavel, Istamet) even while it was an ANDA challenger in the U.S. — the Delhi High Court awarded Merck and Sun (as co‑plaintiff/licensee) ₹81 lakh against a third‑party infringer in January 2026 (https://www.livelawbiz.com/amp/ipr/delhi-high-court-ipr-patent-anti-diabetic-drug-sitagliptin-infringement-suit-decreed-over-81-lakh-damages-awarded-[520530](/patent/520530)).

The technology and the patent. The accused conduct is Sun's submission of an ANDA (referred to in Merck's complaint as Sun's "'423 ANDA" product) containing a paragraph IV certification that the '708 patent is invalid and/or not infringed; the product is generic sitagliptin phosphate tablets corresponding to Januvia/Janumet (Merck complaint, Merck Sharp & Dohme Corp. v. Sun Pharma Global FZE, 1:19‑cv‑00319‑RGA, D. Del., filed 2/13/2019). The '708 patent ("Phosphoric acid salt of a dipeptidyl peptidase‑IV inhibitor") claims the 1:1 dihydrogenphosphate (DHP) salt of sitagliptin, hydrates and crystalline monohydrate forms of that salt, pharmaceutical compositions containing it, and a method of treating Type 2 diabetes — i.e., the salt form that made Januvia commercially viable. The related **'921

Key legal developments & outcome

Major rulings, motions, claim construction, settlements, and the present posture or final disposition.

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Plaintiff representatives

Counsel of record for the plaintiff(s): attorneys, firms, and roles (lead counsel, of counsel, local counsel).

I'll research the counsel of record for the petitioner (plaintiff) in this PTAB proceeding.

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Counsel of Record — Petitioner Sun Pharmaceutical Industries Ltd.

A threshold note on framing: IPR2020-01072 is a PTAB proceeding, not a district court case, so the "plaintiff" is the petitioner, Sun Pharmaceutical Industries Ltd. There is no "local counsel" concept at the Board, and no in-house attorney appeared of record. All of Sun's counsel of record are from a single firm, Winston & Strawn LLP, Washington, D.C. office (1901 L Street NW; some earlier filings give 1700 K Street NW). The information below comes from Sun's Power of Attorney (Paper 1, filed June 12, 2020) and the patent owner's service certifications, which list Sun's attorneys of record.

Lead Counsel

Jovial Wong (Reg. No. 60,115) — Lead counsel

  • Winston & Strawn LLP, Washington, D.C.
  • Concentrates on pharmaceutical/biotech patent litigation and PTAB practice; recognized among the top 10 ANDA litigators in Patexia's 2025 ANDA Litigation Intelligence Report and in IAM Patent 1000 for "pharmaceutical PTAB practice." He signed the Petitioners' Joint Reply in support of the joinder motions in this family of IPRs and is the attorney to whom service was directed on behalf of Sun.

Back-up Counsel

Charles B. ("Chuck") Klein — Back-up counsel (PHV motion noted)

  • Winston & Strawn LLP, Washington, D.C.; litigation office head and former co-chair of the firm's IP practice.
  • First-chair patent/antitrust trial and appellate lawyer with 30+ years of experience; argued Hikma v. Amarin (induced infringement, 9-0 Supreme Court win) and was counsel in Caraco v. Novo Nordisk. World IP Review's 2024 USA Patents ranking identifies Klein and Wong as representing Sun Pharmaceutical.

Claire (Claire A.) Fundakowski — Back-up counsel (motion for PHV to be filed)

  • Winston & Strawn LLP, Washington, D.C.
  • Former pharmacist; pharma/medical-device patent litigator. IAM Patent 1000 notes her patent expertise and a trial win for Intuitive Surgical in Rex Medical (medical staplers).

Zachary B. Cohen — Back-up counsel (motion for PHV to be filed)

  • Winston & Strawn LLP, Washington, D.C.
  • Listed as back-up counsel in Sun's Power of Attorney; appears in the service lists for this IPR. (I did not find a detailed public biography confirmable from the sources retrieved, so I am not characterizing his specific experience.)

Context / caveats

  • These attorneys appear as Sun's representatives via the Power of Attorney filed with the petition (Paper 1, June 12, 2020), and they are the addressees on the Patent Owner's certificates of service (e.g., Paper 8, July 10, 2020). The filings are not sealed — the POA and service lists are public record.
  • The Winston & Strawn team also represented Sun in the parallel Hatch-Waxman litigation, Merck Sharp & Dohme Corp. v. Sun Pharmaceutical Industries Ltd., No. 1:19-cv-00319-RGA (D. Del.), which the Board identified as a related proceeding, and in In re Sitagliptin Phosphate ('708 & '921) Patent Litig., No. 19-md-2902 (D. Del.). A related 2012 Winston filing in New Jersey lists Klein and Wong as "Of Counsel" for Sun entities — but for this IPR, their role is lead/back-up counsel of record as set out above.
  • No attorney has appeared other than the Winston & Strawn practitioners named in the POA. Sun's paralegal/agent contacts (e.g., N. Malik Jitty) appear only on email correspondence and are not counsel of record.

Sources: IPR2020-01072 Paper 1 (Petitioner Power of Attorney, Jun. 12, 2020) and Paper 8 (Patent Owner's Exhibit List, Jul. 10, 2020) via the PTAB docket mirrors (docketalarm.com / gaeflexstaging-dot-docketupdate.appspot.com); Petitioner's Joint Reply in Support of Motions for Joinder (Jul. 29, 2020); Winston & Strawn and World IP Review (USA Patents 2024) attorney profiles.

Defendant representatives

Counsel of record for the defendant(s): attorneys, firms, and roles (lead counsel, of counsel, local counsel).

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Excellent — this confirms Merck (Patent Owner) is represented by Williams & Connolly. Let me confirm the specific counsel of record.

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Counsel of Record — Defendant/Patent Owner Merck Sharp & Dohme Corp.

Threshold clarification: In an IPR the "defendant" is the Patent Owner. In IPR2020-01072 the patent owner is Merck Sharp & Dohme Corp., and its entire PTAB trial team of record is Williams & Connolly LLP, 725 Twelfth Street, N.W., Washington, D.C. 20005 (Reg. No.‑bearing lead/back‑up counsel plus pro hac vice counsel). There is no local counsel in a PTAB proceeding, and no Merck in‑house attorney appears as counsel of record on the PTAB papers — Merck's in‑house team is reachable only through the firm's group service address, MerckSitagliptin@wc.com. Sun's own counsel (Winston & Strawn) appears only as petitioner's counsel and is not relevant to your question.

Lead counsel

Attorney Role Firm / office Note
Stanley E. Fisher (USPTO Reg. No. 55,820) Lead counsel (designated in Merck's mandatory notices; signed the Patent Owner filings, e.g., Paper 8, July 10, 2020) Williams & Connolly LLP, Washington, D.C. W&C patent litigation partner; longtime Merck Hatch‑Waxman/ANDA and PTAB counsel; the Board's institution-and-joinder decision lists him first "FOR PATENT OWNER."

First back-up counsel

Attorney Role Firm / office Note
Jessamyn S. Berniker (Reg. No. 72,328) First back-up counsel (listed on the mandatory notices and on every service certificate in the four co‑pending '708 IPRs) Williams & Connolly LLP, Washington, D.C. Registered patent attorney; part of W&C's core Merck sitagliptin/Januvia team across the IPRs and the parallel D. Del. MDL.

Additional back-up counsel of record

All of the following are listed as Merck's counsel in the Patent Owner filings in IPR2020-01072 (Patent Owner's Exhibit List, Paper 8, and the Sept. 1, 2020 institution/joinder decision):

Attorney Role / admission status Firm / office Note
Bruce R. Genderson Back-up counsel (pro hac vice) Williams & Connolly LLP, Washington, D.C. W&C partner, prominent appellate/first-chair litigator; also appeared for Merck in the N.D. W. Va. Mylan action and on the Federal Circuit brief in Mylan v. Merck, Nos. 21‑2121/21‑2124 (Fed. Cir.).
Alexander S. Zolan Back-up counsel (pro hac vice — motion to be submitted, per Paper 8) Williams & Connolly LLP, Washington, D.C. W&C litigation partner on the Merck sitagliptin team.
Elise M. Baumgarten Back-up counsel (pro hac vice) Williams & Connolly LLP, Washington, D.C. W&C partner; the principal Merck contact on the joinder meet‑and‑confer correspondence (ebaumgarten@wc.com) with the Teva, DRL and Sun "silent understudy" petitioners.
Shaun P. Mahaffy Back-up counsel (Reg. No. 75,534) Williams & Connolly LLP, Washington, D.C. Signed as W&C associate in July 2020 correspondence; registered patent attorney.
Anthony H. Sheh Back-up counsel (Reg. No. 70,576) Williams & Connolly LLP, Washington, D.C. Registered patent attorney; signed the § 42.24(d) certifications in the '708 IPRs.
David M. Krinsky (Reg. No. 72,339) Back-up counsel — added later Williams & Connolly LLP, Washington, D.C. Added via Merck's Fourth Amended Mandatory Notices (Oct. 29, 2020) in the parent IPR2020‑00040, which controls the joined proceeding. Registered patent attorney and W&C partner; Law360 Life Sciences "MVP" (2025), lead counsel for Merck in the Januvia Hatch‑Waxman/ANDA litigation "in both the district court and co‑pending IPR proceedings, and as co‑counsel in the Federal Circuit," and appellee's counsel in the Federal Circuit appeal of the Mylan IPR.

Source notes and caveats

  • Primary sources: PTAB papers in IPR2020‑01072 — Patent Owner's Exhibit List, Paper 8 (July 10, 2020) (full W&C signature block and service list); Sun Pharm. Indus. Ltd. v. Merck Sharp & Dohme Corp., IPR2020‑01072, Paper 12 (PTAB Sept. 1, 2020) (institution + joinder decision listing counsel "FOR PATENT OWNER"); Petitioners' Joint Reply in support of joinder (July 29, 2020) (served on the same seven W&C attorneys plus the MerckSitagliptin@wc.com service address); and Merck's Fourth Amended Mandatory Notices in IPR2020‑00040 (Oct. 29, 2020) (adding Krinsky).
  • Docket/PACER: PTAB filings are not on PACER; the counsel lists above are taken from the publicly posted PTAB papers and PTAB's PTACTS document system rather than a PACER docket sheet. The related district-court MDL, In re Sitagliptin Phosphate ('708 & '921) Patent Litig., No. 1:19‑md‑02902‑RGA (D. Del.), and the N.D. W. Va. action show largely the same W&C team (plus additional W&C attorneys such as Sarahi Uribe, Vanessa Omoroghowman and Jihad Komis in later district-court filings — I did not confirm these as PTAB counsel of record here).
  • Sealed/absent filings: The joinder‑related discovery correspondence was public (it was filed as Exhibits 2029, 2036–2038). I found no indication that any IPR2020‑01072 filing was sealed; the papers are publicly available. No separate power of attorney or appearance listing an attorney outside Williams & Connolly was located.
  • Unverified: I was unable to independently confirm current firm affiliations or bios for every attorney (e.g., whether Berniker, Baumgarten, Zolan or Sheh remain at W&C as of today, and the details of their individual case histories beyond the '708 matter). Where I have not verified experience, I have limited the note to the role documented in the record rather than assert a biography. I found no basis to identify any Merck in‑house lawyer as counsel of record in this IPR.

Case posture (context for the counsel question): IPR2020‑01072 was instituted and joined to Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp., IPR2020‑00040, on September 1, 2020, with Sun as a "silent understudy" bound by Mylan's filings, and the joined proceeding was resolved by the Board's Final Written Decision of May 7, 2021 (no challenged claims of the '708 patent unpatentable), affirmed in Mylan Pharms. Inc. v. Merck Sharp & Dohme Corp., No. 21‑2121 (Fed. Cir. Sept. 29, 2022). Because Sun was a silent understudy, Merck's Williams & Connolly team litigated the merits primarily against Mylan's counsel, but remained counsel of record for Merck in the joined IPR2020‑01072 file.