Merck Sharp & Dohme Corp. v. Anchen Pharmaceuticals, Inc. et al.

I'll research this case before drafting the overview.

Let me verify the IPR outcomes and related proceedings.

Let me verify the Par declaratory judgment action and the MDL structure.

Case Overview and Background

Parties. This is a conventional Hatch‑Waxman, branded‑versus‑generic action rather than an NPE/PAE assertion. The plaintiff, Merck Sharp & Dohme Corp. ("MSD"), is the New Jersey‑based operating subsidiary of Merck & Co., Inc. and the holder of NDA No. 202270 for Janumet XR (sitagliptin phosphate/metformin HCl extended‑release tablets), as well as the Orange‑Book‑listed sitagliptin franchise (Januvia, Janumet). The defendants, Anchen Pharmaceuticals, Inc. (a Delaware corporation headquartered in Irvine, California) and Par Pharmaceutical, Inc. (a New York corporation in Chestnut Ridge, New York), are generic ANDA filers and affiliates of Endo International plc — Par is a wholly owned indirect subsidiary of Endo, and Anchen a wholly owned indirect subsidiary of Par (per the Rule 7.1 disclosures at D.I. 9–10 and the counterclaim allegations in the Answer, https://paragraphfour.com/uploads/cases19/dedc19cv0311A.pdf). There is no university, non‑practicing entity, or start‑up patent holder here; both sides are commercial pharmaceutical manufacturers.

Accused product and patent. Merck accused Anchen's ANDA No. 204144, a proposed generic version of Janumet XR (sitagliptin phosphate/metformin HCl ER tablets, 50/500 mg, 50/1000 mg, 100/1000 mg), which Par's separate declaratory judgment complaint identifies as "Par's ANDA Product" (see Par's complaint, https://paragraphfour.com/uploads/cases19/njdc19cv4432C.pdf). Only one patent is on this case's docket: U.S. Patent No. 7,326,708, titled "Phosphoric Acid Salt of a Dipeptidyl Peptidase‑IV Inhibitor," issued February 5, 2008, with a June 24, 2003 priority date and a docket‑reported expiration

I'll research this case across PACER, court opinions, PTAB, and legal news sources.

Good foundation. Let me dig into the docket, the claim construction ruling, the parallel PTAB proceedings, and the separate Par DJ action.

Merck Sharp & Dohme Corp. v. Anchen Pharmaceuticals, Inc. et al., No. 1:19-cv-00311-RGA (D. Del.)

Below is the chronological legal-development timeline for this action, supplementing (not repeating) the existing summary. Where a fact rests on a secondary aggregator rather than a primary document, I flag it.

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0. Posture snapshot

The 19-311 action never reached trial. It was folded into Judge Andrews' consolidated sitagliptin proceeding, litigated claim construction and expert discovery, and ended by a negotiated consent judgment on 2021-03-02 while a parallel IPR on the '708 patent was pending. The '708 patent ultimately survived both the IPR and the Federal Circuit appeal (2022-09-29).

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1. Pre-suit and filing (2019-02-01 – 2019-02-13)

• 2019-02-01 — Par Pharmaceutical, Inc. filed a separate declaratory judgment action against Merck in the District of New Jersey, No. 2:19-cv-04432, over the same ANDA and the same '708 patent. Source: paragraphfour.com case entry (secondary/aggregator — moderate confidence; I could not confirm the NJ docket directly).
• 2019-02-13 — Merck filed the Delaware complaint (D.I. 1), asserting the '708 patent under 35 U.S.C. § 271(e)(2) against Anchen Pharmaceuticals, Inc. and Par Pharmaceutical, Inc. The suit was triggered by ANDA No. 204144 for generic JANUMET XR® (sitagliptin + metformin HCl ER). The complaint alleges the Paragraph

I'll search multiple angles to find press coverage of this case.

The first pass returned mostly court documents. Let me search specifically for press coverage of the settlement and related reporting.

Let me search targeted legal-trade and business press angles.

I ran searches on the caption, the party names, the ANDA number, the '708 patent number, the settlement/consent judgment, and the parallel IPR/appeal, across general web, legal-trade and pharma-trade sources. Here is what the press record actually shows.

Bottom line: this specific case generated essentially no dedicated press coverage. I could not locate a single article from Reuters, Bloomberg Law, Law360, IPWatchdog, Patently-O, Ars Technica, The Verge, JD Supra or any mainstream outlet that reports on Merck Sharp & Dohme Corp. v. Anchen Pharmaceuticals, Inc., No. 1:19-cv-00311-RGA, by caption, case number, or as a discrete event. That is consistent with the case's profile: it was one of roughly fourteen substantively identicalParagraph IV suits folded into MDL No. 19-2902, it produced no trial, no verdict, no damages phase, and no written liability ruling, and it ended in a confidential consent judgment (D.I. 154, 3/2/2021). Trade press covering the sitagliptin litigation instead concentrated on the one defendant that actually tried the case — Viatris/Mylan, in N.D. W. Va. — and on the '708 IPR and Federal Circuit appeal, because those events produced an adjudicated outcome. I note the caveat that Law360 and Bloomberg Law are paywalled and poorly indexed; the absence of hits in my searches is strong but not conclusive evidence that no short item exists behind those paywalls.

The closest thing to press coverage is corporate and trade reporting on the sitagliptin franchise as a whole, which reaches this case only by implication. Merck issued a Business Wire release on 2022-09-22 announcing its win against Viatris, and in it stated that the '708 patent "is set to expire on Nov. 24, 2026, with pediatric exclusivity extending to May 24, 2027," that the Patent Office had on 2021-05-07 found all challenged claims valid, and — most relevant here — that Merck "has entered into patent litigation settlement agreements with multiple generic companies, allowing them to bring their generic versions of JANUVIA and JANUMET to the market in the U.S. in May 2026 or earlier under certain circumstances, and their generic versions of JANUMET XR to the market in July 2026 or earlier under certain circumstances." Anchen/Par is never named in that release, but Anchen's ANDA No. 204144 is a Janumet XR ANDA, so the July 2026 date is the only public statement touching this case's commercial outcome. Pharmaphorum framed the same cluster of events in analyst terms, describing the Federal Circuit affirmance and the West Virginia judgment as "a big victory for Merck" that "look[s] set to protect its third biggest-selling drug for another few years," and reporting that Merck "has previously reached settlement agreements with more than 20 other generics companies that have deferred their launch plans for generics until May or July 2026 depending on the formulation, 'or earlier under certain circumstances'" — explicitly contrasting Viatris, which "eschewed a settlement deal," with the settling defendants. Neither outlet quantifies what Anchen/Par gave up or received. A Chinese-language industry piece on sitagliptin patent expirations (PharmCube/bydrug) is the only trade article I found that names Par directly, noting that Merck's litigation with generic manufacturers included "Par Pharmaceuticals" and that "Par Pharmaceutical challenged the validity of that patent," which it described as expiring in 2027.

On settlement terms and numbers, there is no press reporting at all; the only quasi-public account is Merck's own SEC disclosure. The consent judgment (D.I. 154) recites a confidential "Settlement Agreement," enjoins Anchen and its affiliates from infringing the '708 patent as to the ANDA No. 204144 product absent authorization, and dismisses all claims and counterclaims with prejudice and without costs or attorneys' fees — but it discloses no entry date, no royalty, no license terms, and no consideration. No money damages were ever sought or awarded in this § 271(e)(2) action, and no outlet has reported a figure. Merck's periodic reports are the only place the case surfaces publicly in narrative form at all: its Q3 2020 10-Q explained that "Par Pharmaceutical dismissed its case in the U.S. District Court for the District of New Jersey against the Company and will litigate the action in the U.S. District Court for the District of Delaware," and its later 10-Q confirmed that "[p]rior to the beginning of the scheduled October 2021 trial in the U.S. District Court for the District of Delaware on invalidity issues, the Company settled with all defendants scheduled to participate in that trial," with total settlements reaching "25 generic companies" as of early 2023 — the July 2026 Janumet XR entry date being the aggregate, group-wide figure. Merck's 2022 annual-period disclosure uses the then-current count of 22 generic companies with the same May/July 2026 framing.

Where accounts diverge or outrun the record. First, none of the above coverage names this case, so attributing the July 2026 Janumet XR date specifically to Anchen/Par goes beyond both the press and the court record — Merck states it as an aggregate across the defendant group, and the Anchen/Par agreement itself is confidential. Second, the secondary case trackers are internally inconsistent on this docket: the paragraphfour.com entry for C.A. No. 19-311 correctly notes "Consent Judgment entered 3/2/21" and that Par's New Jersey declaratory action (No. 2:19-cv-04432, filed 2/1/2019) was "dismissed 2/21/19," but another block on the same page states of the same case, "Settled and Consent Judgment entered 7/16/20" — a date the docket does not support — and lists "Matthew Becker/Axinn Veltrop" as defense counsel in one row while naming David Silverstein in the adjacent row, where the docket and the 11/17/2020 Markman caption show Silverstein, Aziz Burgy and Christopher Gallo. I flag these as tracker errors, not press accounts. Third, the interpretative gloss — Pharmaphorum's characterization of the sitagliptin outcomes as a market-exclusivity victory preserving the franchise "until at least 2026" — is editorial/analyst framing rather than something drawn from any ruling in this case, which never adjudicated the '708 patent's validity or infringement as to Anchen.

Sources

• As previously disclosed, beginning in 2019, a number of generic drug companies filed ANDAs seeking approval of generic forms of ...
• UNITED STATES JUDICIAL PANEL on MULTIDISTRICT LITIGATION
• IN THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF DELAWARE
• UNITED STATES PATENT AND TRADEMARK OFFICE
• IN THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF DELAWARE
• Jason B
• IN THE UNITED STATES DISTRICT COURT FOR THE NORTHERN DISTRICT OF WEST VIRGINIA
• 38. Alvogen states that this paragraph of the Complaint contains allegations that do not accurately reflect the contents of Alvo...
• Merck Sharp & Dohme Corp
• Merck Sharp & Dohme Corp. v. Anchen Pharmaceuticals, Inc. – CourtListener.com - Trial Court Document
• sitagliptin phosphate drug patent lawsuits and PTAB cases for small molecule and biologic drugs - Last Updated: March 17, 2026
• SITAGLIPTIN PHOSPHATE drug patent litigation and PTAB cases for biologic and small molecule drugs - Last Updated: March 17, 2026

I'll research the plaintiff's counsel of record in this case.

I have strong leads. Let me verify the plaintiff's counsel roster and the entry dates.

Let me pull the docket sheet's counsel listing and the complaint signature block.

Plaintiff's Counsel of Record — Merck Sharp & Dohme Corp.

Merck (the sole plaintiff in C.A. No. 19-311-RGA, a member case of In re Sitagliptin Phosphate ('708 & '921) Patent Litigation, MDL No. 19-2902-RGA) was represented by a two-firm team: Delaware local counsel McCarter & English, LLP and national/lead trial counsel Williams & Connolly LLP of Washington, D.C. No in-house Merck attorneys are listed on the docket as counsel of record.

The most reliable single source for the full plaintiff-side roster in this case is the Consent Judgment signature block (D.I. 154, filed 3/2/2021), where both firms appear under "Attorneys for Merck," corroborated by the pro hac vice admission entries on the docket and the MDL docket sheet.

Local counsel — McCarter & English, LLP (Wilmington, DE)

Lead / national counsel — Williams & Connolly LLP (Washington, DC)

All appeared pro hac vice. The core group moved for admission on 2/21/2019 (D.I. 6, granted 2/22/2019), with additional admissions later:

Sourcing, gaps, and cautions

• Docket confirmation of appearance dates: D.I. 6 (PHV motion for Genderson, Berniker, Fisher, Mahaffy, Sheh, Luo, granted 2/22/2019); D.I. 13 (PHV for Zolan, 4/29/2019); the 3/7–3/8/2019 and 5/18/2020 docket notices adding Luo, Sheh, and Baumgarten "for electronic noticing"; D.I. 148/156 for the Ho appearance and withdrawal. See the CourtListener docket, https://www.courtlistener.com/docket/14640213/merck-sharp-dohme-corp-v-anchen-pharmaceuticals-inc/.
• Consent judgment roster: https://storage.courtlistener.com/recap/gov.uscourts.ded.67784/gov.uscourts.ded.67784.154.0.pdf (D.I. 154, McCarter block and Williams & Connolly block).
• MDL docket sheet (listing Kelly, Genderson, Berniker, and Zolan as "represented by" Merck in the consolidated proceeding): reproduced at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1537482](/patent/1537482)/download-materials.
• Markman opinion caption: https://cases.justia.com/federal/district-courts/delaware/dedce/1:2019cv00311/[67784/135](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=67784-0135)/0.pdf (D.I. 135, listing only Silver and Joyce for Plaintiff).

Two caveats for accuracy:

1. Individual titles (partner/counsel/associate) are drawn from firm profiles and general public reporting, not from docket captions, which do not state titles. Those labels are reliable for Genderson, Berniker, Fisher, Zolan, Mahaffy, Silver, Joyce, and Kelly; they are less certain for the more junior Williams & Connolly names (Uribe, Komis, Luo, Sheh, Baumgarten, Ho), where I could not independently confirm current title at the time of the case.
2. I could not retrieve a live PACER "attorneys for plaintiff" header screen for this exact member case (PACER sits behind a paywall). The roster above is reconstructed from the Consent Judgment signature block, the PHV docket entries, and the MDL docket sheet — all consistent with one another. If any attorney appeared and withdrew without a docketed signature (unlikely here, given the case's short life), that individual would not be captured. Note also that this case's local counsel at McCarter overlapped heavily with Merck's counsel in the parallel sitagliptin cases and in later Janumet XR suits (e.g., Merck Sharp & Dohme LLC v. Aurobindo Pharma Ltd., 1:25-cv-00449-RGA), where McCarter & English likewise appeared for Merck — consistent with the pattern here.

I'll research the defense counsel in this case using targeted searches.

Let me verify the individual defense attorneys' firms, roles, and patent litigation experience.

Defense Counsel of Record

Defendants Anchen Pharmaceuticals, Inc. and Par Pharmaceutical, Inc. were represented by a two-firm team: a Delaware local-counsel firm handling filings and a Washington/New York IP boutique acting as lead trial counsel. All defense-side counsel appeared for both defendants jointly — the docket entries in this case and the related Sitagliptin MDL (No. 19-2902-RGA) caption them "Attorneys for Anchen and Par."

The roster below is drawn from the case docket, the pro hac vice motions and orders, the Answer/counterclaim (D.I. 9), the Markman opinion (D.I. 135, filed 11/17/2020), and the consent judgment (D.I. 154, entered 3/2/2021).

Delaware Local Counsel — Richards, Layton & Finger, P.A. (Wilmington, DE)

Lead Trial Counsel — Axinn, Veltrop & Harkrider LLP

The three Axinn attorneys were admitted pro hac vice by the order at D.I. 11 (motion filed 3/7/2019; SO ORDERED 3/12/2019), which the docket describes as "MOTION for Pro Hac Vice Appearance of Attorney David H. Silverstein, Aziz Burgy, and Christopher M. Gallo … filed by Anchen Pharmaceuticals, Inc., Par Pharmaceuticals, Inc."

Sources and caveats

• Docket/firm attribution is well-sourced. The pro hac vice order and CM/ECF noticing entry (docket entries dated 3/12–3/13/2019) confirm Silverstein, Burgy, and Gallo as defense PHV counsel; the Answer (D.I. 9) and consent judgment (D.I. 154) confirm Fineman and Mowery for RLF. The 11/17/2020 Markman opinion (D.I. 135) lists "Aziz Burgy (argued), Christopher Gallo, David Silverstein, AXINN VELTROP & HARKRIDER LLP … Steven J. Fineman, RICHARDS LAYTON & FINGER P.A., … attorneys for Defendants Par and Anchen." Sources: Justia docket; D.I. 135; D.I. 154.
• No in-house counsel of record appears on this docket for Anchen/Par. Par (an Endo subsidiary) has in-house IP staff, but I found no entry of appearance by an in-house attorney here — the defense was handled entirely by outside counsel above.
• Firm/office details reflect the time of the case. Burgy's current Axinn address is 950 F St. NW, Washington, D.C.; Silverstein has since left Axinn (now at Rocket Pharmaceuticals); Gallo has since left Axinn (now Sterne Kessler). I did not independently verify a formal 2023 withdrawal-of-appearance filing for Silverstein/Gallo on this docket, so if a precise "appeared through date" matters, that should be confirmed against the docket.
• I did not locate any sealed defense entries of appearance. The consent judgment (D.I. 154) recites that the parties settled under a confidential Settlement Agreement, but the counsel signatures are public and consistent with the roster above.

A note for the case file: the plaintiff's side (McCarter & English LLP locally, with Williams & Connolly LLP and later Morgan, Lewis & Bockius handling merits) is documented separately in the overview section and is not restated here.