Merck KGaA et al. v. Apotex Inc. et al.

I'll research this case across the docket, court opinions, and legal press.

Let me pull the docket status, IPR details, and the Federal Circuit outcome.

Good progress. Let me nail down the Apotex-specific docket events, IPRs, and market outcome.

Background and parties

This is a Hatch‑Waxman ANDA case in the District of Delaware in which Merck KGaA, Merck Serono SA, and Ares Trading SA (the Merck KGaA group; Merck Serono is the operating R&D/pharma entity acquired by Merck KGaA in 2006, and Ares Trading is a Merck affiliate that holds/co‑owns the MS franchise assets) sued Apotex Inc. (Canada) and Apotex Corp. (U.S.) — one of the largest privately held generic manufacturers, and a frequent D. Del. defendant. All three plaintiffs are operating companies, not NPEs; the patents at issue descend from Serono's own development of Mavenclad® (oral cladribine 10 mg tablets) for relapsing forms of multiple sclerosis, and from a 2002–2004 Serono/IVAX joint development effort (Fed. Cir. opinion, Merck Serono S.A. v. Hopewell Pharma Ventures, Inc., Nos. 2025‑1210/‑1211, Oct. 30, 2025). Merck's U.S. filings were led by Wilmington counsel (docket entries show Jeremy A. Tigan signing for plaintiffs), with WilmerHale appearing for Merck Serono in the parallel PTAB proceedings (see the Kan declaration in IPR2023‑00049/‑00050). Apotex's docket filings appear under Cortlan Hitch. The accused product is Apotex's proposed generic cladribine 10 mg tablets, ANDA No. 218425, which FDA's approval letter confirms is bioequivalent/therrapeutically equivalent to EMD Serono's Mavenclad (NDA 022561); the theory is the § 271(e)(2) artificial act of infringement plus induced/contributory infringement by Apotex's proposed label (Compl. ¶¶ 26, 30–55, D. Del. 1:23‑cv‑00655).

Patents and procedural posture

The original complaint (filed June 15, 2023, within the 45‑day window after Apotex's March 22, 2023 ANDA submission) asserted three method‑of‑treatment patents: U.S. 7,713,947 and U.S. 8,377,903, both titled "Cladribine Regimen for Treating Multiple Sclerosis" and both claiming a multi‑phase oral cladribine regimen — an induction period of roughly 2–4 months at a cumulative ~1.7–3.5 mg/kg, an ~8–10 month cladribine‑free period, a maintenance/retreatment period, and a second drug‑free interval (asserted claims: '947 cl. 36, 38, 39, 41–46; '903 cl. 17, 19, 20, 22–27); and U.S. 10,849,919 ("Cladribine Regimen for Treating Progressive Forms of MS"), covering treatment of primary/secondary progressive MS. The '919 patent was dropped — consistent with Apotex having filed only a § 505(j)(2)(A)(viii) section viii statement that the '919 is a method‑of‑use patent not covering its approved indication (FDA approval letter, ANDA 218425, Nov. 24, 2025; a parallel stipulation dismissing the '919 as to Aurobindo appears at D.I. 64 in 22‑1365). The case was consolidated into the earlier MDL‑style lead action, Civ. No. 22‑1365‑GBW‑CJB (Merck KGaA v. Hopewell Pharma Ventures), with all pretrial matters before Judge Gregory B. Williams and Magistrate Judge Christopher J. Burke; a joint Markman hearing was held Jan. 30, 2024, and Judge Burke's June 13, 2024 Report and Recommendation (D.I. 141 in 22‑1365) adopted Merck's proposed constructions of "induction period"/"maintenance period" over the defendants' narrower "lower dose" reading, and a bench trial was set for Jan. 13, 2025 (scheduling order, D.I. 31 in 23‑655). Delaware matters here both as the near‑universal Hatch‑Waxman forum for its speed and its deep ANDA docket, and because Apotex did not press a venue/jurisdictional objection — a motion to dismiss filed at D.I. 13 was withdrawn in November 2023 (D.I. 26, 27); I could not verify from available sources what grounds that motion asserted.

Why the case matters, and how it ended

The case became a leading example of IPR‑driven case collapse. Two generic challengers — Hopewell (IPR2023‑00480/‑00481, filed Jan. 2023) and TWi Pharmaceuticals (IPR2023‑00049/‑00050) — challenged the '947 and '903 claims, and the PTAB invalidated all asserted claims as obvious over the Bodor PCT publication (WO 2004/087101, a Serono/IVAX joint‑development reference) in view of Stelmasiak (1998) (FWDs Sept. 18, 2024). The court therefore imposed a sua sponte global stay of all defendants' cases pending appeal, while declining to toll the 30‑month statutory stay as to Apotex — Apotex affirmatively told the court it would not oppose a global stay but objected to any extension of its own regulatory stay, positioning itself to launch at risk. On Oct. 30, 2025 the Federal Circuit affirmed (precedential opinion in the Hopewell appeals), holding that where a prior‑art reference and the patent share only some inventors, the reference is still "by another" absent proof that the relied‑upon disclosure reflects the collective work of all named inventors — a doctrinal clarification litigants have flagged as significant for joint‑inventorship prior‑art fights under pre‑AIA §§ 102(a)/(e); a companion nonprecedential opinion rejected the same arguments in the TWi appeals (Nos. 2025‑1463/‑1464), and rehearing was later denied. Because the invalidation became final, the '947 and '903 patents ceased to block generic cladribine: FDA approved Apotex's ANDA 218425 on Nov. 24, 2025 (following a tentative approval Oct. 8, 2025), with the Orange Book listing the '947 as expiring Oct. 16, 2026 and the '903 as expiring May 31, 2026 — remarkably short remaining life, which is part of why the litigation's commercial stakes hung on interim exclusivity rather than a long tail. In a related, much‑watched ruling, Judge Williams refused Hopewell's emergency motion to shorten the 30‑month stay before the appellate mandate issued, holding the court lacked authority to alter the statutory stay to cure competitive prejudice (Merck KGaA v. Hopewell Pharma Ventures, 2025 WL 3485555 (D. Del. Dec. 4, 2025)) — a decision that left Hopewell, the earlier filer and IPR victor, potentially behind Apotex at the market. Market context: Mavenclad generated roughly €1.1 billion (~$1.3 billion) in 2024 worldwide sales (Husch Blackwell client note), so the case sat at the intersection of a blockbuster‑scale MS brand, an early‑filer/late‑launcher generic horse race, and coordinated PTAB invalidation; the 23‑655 docket shows the action closed on Feb. 2, 2026 per a third‑party case tracker (not independently confirmed on PACER here). I could not verify from available sources the actual at‑risk launch date of Apotex's generic or whether any settlement/license preceded it; those points should be checked against FDA/D. Del. docket updates before being stated as fact.

I'll research the docket events, motions, and PTAB history to build the chronological development list.

Key details are emerging. Let me dig into the 23-655 docket specifics, the '919 IPR, and the final disposition.

I'll search for press coverage of this specific litigation from several angles.

Good material. Let me dig into trade/mainstream coverage of the market impact and any Law360/Reuters reporting.

Direct press coverage of Merck KGaA v. Apotex specifically is thin; the case is covered almost entirely through the appeals ruling it spawned. Searching the caption, the parties, the patent numbers and the "verdict/settlement" angles turned up no Reuters, Bloomberg Law, Law360, Ars Technica, The Verge, Patently-O or EFF item about C.A. No. 1:23-cv-00655. The closest thing to case-specific press is a litigation-analytics write-up by Patsnap, which frames the case as "Cladribine MS patents ruled invalid as obvious," reports the case as filed 15 Jun 2023 and closed 2 Feb 2026 (963 days, 3 patents asserted), and quotes the Feb. 2, 2026 Delaware closing entry as resting on Merck Serono S.A. v. Hopewell Pharma Ventures, Inc., Nos. 2025-1210/‑1211, 159 F.4th 10 (Fed. Cir. 2025) and the January 2026 mandate. Patsnap ran a mirror post for the parallel Aurobindo action. No outlet reported a damages award, verdict, or settlement term in the Apotex case, and none reported the withdrawn motion to dismiss — consistent with the ANDA action being stayed globally and then resolved on the patents rather than on Apotex's own conduct.

The bulk of coverage is legal-trade analysis of the Oct. 30, 2025 Federal Circuit decision invalidating the '947 and '903 claims. IPWatchdog reported the same day that the precedential opinion (authored by Judge Linn) rejected Merck's argument that the Bodor reference was not "by another" because inventor De Luca contributed to Bodor's six-line disclosure, and highlighted the court's rule that "when the patented invention is the result of the work of joint inventors, the portions of the reference disclosure relied upon must reflect the collective work of the same inventive entity identified in the patent." White & Case and A&O Shearman both published client alerts reading the decision as a strict "complete identity of inventive entity" rule, and Barnes & Thornburg drew the practical lesson for joint-development partners — keep contemporaneous inventorship records — while noting the AIA timing point that pre-AIA law governed an invention born of the 2002 Serono/IVAX collaboration. Alston & Bird summarized the substantive affirmance on obviousness over Bodor + Stelmasiak as supported by substantial evidence, and WHDA distilled it to "If It Isn't The Same, It's Different!" None of these outlets mentions Apotex by name as a party; they cover the patents, i.e., the same invalidation that freed Apotex's ANDA.

On the Hatch-Waxman/market side, the most substantive coverage is a firm bulletin and a trade special report. Robbins Kaplan (2025 Q4 GENERically Speaking) is the only source found that discusses Apotex's litigation position directly: it reports that the court imposed a sua sponte global stay over all defendants but declined to toll the 30-month stay as to Apotex's ANDA, that Apotex told the court it was "amenable to a global stay" if it could seek to lift its own 30-month stay without waiting for the mandate, and that Hopewell's emergency motion to shorten its stay was denied because the court lacked power to alter the statutory stay (citing Merck KGaA v. Hopewell Pharma Ventures, 2025 WL 3485555 (D. Del. Dec. 4, 2025)). [FiercePharma](https://www.fiercepharma.com/special-reports/top-10-drugs-l

Sources

• Merck KGaA v. Hopewell Pharma Ventures, Inc.
• Merck KGaA v. Apotex | Patent Lawsuit 1:23-cv-00655 - Merck KGaA v. Apotex, Inc.
• IN THE UNITED STATES DISTRICT COURT
• CLADRIBINE drug patent lawsuits and PTAB cases for biologic and small molecule drugs - Last Updated: May 2, 2026
• IN THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF DELAWARE
• cladribine drug patent court cases and PTAB cases for small molecule and biologic drugs - Last Updated: April 7, 2026
• Merck KGaA v. Aurobindo Pharma | Patent Lawsuit 1:23-cv-00039 - Merck KGaA v. Aurobindo Pharma, Ltd.
• Merck KGaA v. Hopewell Pharma Ventures, Inc., 1:22-cv-01365 - CourtListener.com - You built today’s CourtListener
• Merck Co., Inc. v. Apotex, Inc. - From Casetext: Smarter Legal Research
• ANDA 218425
• The top 10 drugs losing US exclusivity in 2026 - 2025 North American sales: $716 million (635 million euros)
• Generic Mavenclad Availability & Release Date - Generic Mavenclad Availability

I'll research the plaintiff-side counsel of record across the docket, firm announcements, and court opinions.

Good — plaintiff-side Delaware counsel is emerging. Let me verify the full team and any pro hac vice admissions in the Apotex docket specifically.

Bottom line

I could reach the docket-aggregator records for 1:23‑cv‑00655 and the lead consolidated case (22‑1365), plus the parallel PTAB filings. The plaintiff-side roster is two-tiered: Delaware counsel of record from Morris, Nichols, Arsht & Tunnell LLP, and a substantive patent-litigation team from Wilmer Cutler Pickering Hale and Dorr LLP (which is the firm of record for Merck Serono in the IPRs and appears in the district court via pro hac vice). I did not find any in-house attorney of record, and I could not verify from primary PACER the complete pro hac vice roster in 23‑655 specifically — see the verification notes at the end.

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Delaware counsel of record — Morris, Nichols, Arsht & Tunnell LLP (Wilmington, DE)

Both are identified as Merck KGaA's counsel of record in third-party docket-derived records for 1:23‑cv‑00655 ("Jack B. Blumenfeld · Jeremy A. Tigan … Morris, Nichols, Arsht & Tunnell LLP"). This is consistent with, and refines, the earlier section of this case note that flagged Tigan as the signing attorney.

Also appearing for Merck plaintiffs in the consolidated lead case (22‑1365) is Karen Elizabeth Keller — but note that in the records I retrieved Keller is docketed as defendant-side counsel (Shaw Keller LLP) for Apotex-related defendants, not for Merck. I flag this only because the same surname-adjacent names create easy confusion; I found no Morris Nichols "Keller" on the Merck side.

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Out-of-state / merits team — Wilmer Cutler Pickering Hale and Dorr LLP

WilmerHale is counsel for Patent Owner Merck Serono S.A. in the parallel IPRs (IPR2023‑00049/‑00050, TWi v. Merck Serono; IPR2023‑00480/‑00481/‑00482, Hopewell v. Merck Serono). The counsel block served in those proceedings (e.g., Peitioner's Demonstratives, Paper 83 in IPR2023‑00049, Sept. 26, 2024) lists:

WilmerHale's collective service address in the IPRs was WHMerckMavencladIPRs@wilmerhale.com — a dedicated Merck/Mavenclad docket, indicating a full team staffed across the IPR and district court tracks.

Important distinction: for the WilmerHale attorneys, I have primary-source confirmation of their appearance in the PTAB proceedings (PTAB mandatory notices and served papers), and only secondary/aggregator-level confirmation of their appearance in D. Del. 23‑655 (Farrell's and Gu's attorney-profile case links). I could not pull the actual pro hac vice motions and orders from the 23‑655 docket to confirm each name defendant-by-plaintiff.

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In-house counsel

None identified. I found no Merck KGaA / EMD Serono in-house attorney appearing of record in 1:23‑cv‑00655 or 22‑1365 in the sources I could retrieve. The patent-prosecution attorney of record for the '919 patent (John D. Ulm; prosecution firm Grüneberg Global IP, PLLC) is not litigation counsel and should not be listed as such.

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Verification notes and gaps (please read before relying on this)

1. No direct PACER access. All docket-level facts here come from CourtListener RECAP PDFs, Patexia's docket transcription for "Merck KGaA et al v. Apotex Inc. et al," Patsnap's litigation record, Docket Alarm (which hosts the actual 22‑1365 docket sheet as an IPR exhibit), drugpatentwatch, and UniCourt. The authoritative source for "counsel of record" remains the 23‑655 docket sheet and any D.I. motions for pro hac vice admission — which I could not open directly.
2. The two attorney names I can state with high confidence as plaintiff counsel of record in 23‑655 are Blumenfeld (lead) and Tigan. Both appear consistently across at least three independent aggregators and in the 22‑1365 docket sheet.
3. The WilmerHale names are high confidence for the IPRs and medium confidence for the district court case. If the deliverable requires per-attorney docket citations for D. Del. appearances, that should be checked against D.I. entries for pro hac vice motions in 23‑655 (which would have been filed in mid-2023) before publication.
4. One minor internal contradiction to flag: drugpatentwatch's 22‑1365 page truncates the plaintiffs' attorney list as "Christopher B. …" with the firm listed as Morris Nichols. I could not verify who that is, and I am not naming a "Christopher B." attorney because doing so would require guessing. The 22‑1365 docket sheet exhibit and UniCourt both list only Blumenfeld and Tigan for plaintiffs, so the "Christopher B." entry may be a data-scraping artifact or a non-appearing/departed attorney.
5. Defense-side context (not the ask, but useful for completeness): Apotex is represented by Kenneth L. Dorsney and Cortlan S. Hitch of Morris James LLP (Wilmington) — the Patsnap record for 23‑655 matches this, and Morris James is Apotex's standard Delaware local counsel. Out-of-state Apotex counsel in related ANDA matters (Hoffmann-La Roche, Eagle, Pfizer, Janssen, Vanda) include Windels Marx (Huttner, Ast-Gmoser, Lief) and Katten Muchin Rosenman (Janusz, Sodikoff, Schweers, Schurr-Hendrix); those are related-case firms, not confirmed for 23‑655.
6. Timing caveat: the case closed Feb. 2, 2026, so counsel of record is historical/final rather than "current." There should be no pending appearances to update.

I'll research the docket entries and counsel appearances for the Apotex defendants.

Let me look for the Apotex answer/appearances in the 23-655 docket specifically.

Let me find the Apotex answer and any counsel signature blocks in the 23-655 docket.

Bottom line

The only counsel I can confirm of record for the Apotex defendants in C.A. No. 1:23‑cv‑00655‑GBW‑CJB are the two Morris James LLP Delaware lawyers listed in the docket‑derived counsel record for that case:

Source: Patsnap Litigation Data case record for 1:23‑cv‑00655, which lists for Apotex, Inc. "Cortlan S. Hitch · Kenneth Laurence Dorsney — Firm: Morris James LLP," with the notation that "attorney names appear as recorded in the docket." This is consistent with the earlier case section noting Apotex's D. Del. filings in this matter appear under Cortlan Hitch.

Note the case is now closed (judgment entered Feb. 2, 2026 in favor of Apotex Inc. and Apotex Corp. on the '947 and '903 patents, following the Federal Circuit mandate of Jan. 29, 2026), so the counsel of record is final and no further appearances are expected.

Important caveats — what I could NOT confirm

• I could not verify a Katten Muchin Rosenman appearance in 23‑655 itself. Katten is Apotex's national ANDA/patent‑litigation counsel in the parallel Delaware Apotex matters — for example, in Pfizer Inc. v. Apotex Inc., C.A. No. 24‑621‑CFC (D. Del.), Katten's team is Deepro R. Mukerjee, Lance A. Soderstrom, Christopher B. Prescott (New York), Joseph M. Janusz (Charlotte) and Jillian M. Schurr‑Hendrix (Dallas), with Morris James (Dorsney/Hitch) as Delaware counsel (see D.I. 236, 261 certificates of service in 24‑621) — and the same Katten/Morris James pairing appears in Eagle Pharmaceuticals v. Apotex, C.A. No. 24‑64‑JLH (per the 2024 discovery meet‑and‑confer correspondence referencing Katten's Dawn S. El‑Khoury and Morris James's Dorsney/Hitch). But I have no filing‑level confirmation that Katten entered an appearance in 23‑655. Do not state that Katten was of record here without pulling the docket sheet.
• Cozen O'Connor (Washington, D.C.) also regularly represents Apotex in Hatch‑Waxman matters — co‑chairs W. Blake Coblentz, Aaron Lukas and Barry P. Golob (Cozen Hatch‑Waxman/Biologics practice materials; e.g., the Vanda/Hetlioz trial win affirmed by the Federal Circuit). Again, I found no confirmation of a Cozen appearance in 23‑655.
• Farnan LLP (Brian E. Farnan) is listed among counsel who have represented Apotex Inc./Apotex Corp. in Delaware patent cases on Plainsite, but that is a client‑listing inference, not an appearance in 23‑655.
• No in‑house attorney appears in the docket‑derived record for this case. The only Apotex in‑house name surfaced is non‑legal: Dr. Kiran Krishnan, SVP, Global Regulatory Affairs, listed as the regulatory contact on FDA's ANDA 218425 approval letter (Nov. 24, 2025).
• The lawsuit's own signature blocks that I could retrieve are plaintiff‑side, not Apotex: the June 15, 2023 complaint (paragraphfour.com PDF "dedc23cv0655C") is signed by Jack B. Blumenfeld (#1014) and Jeremy A. Tigan (#5239) of Morris, Nichols, Arsht & Tunnell LLP (Wilmington), with WilmerHale of counsel (David B. Bassett, Gillian T. Farrell, Vinita Ferrera, Emily R. Whelan, Deric Geng, David Mlaver). Listing these as defense counsel would be an error.
• I also could not retrieve the Apotex answer/counterclaims PDF for 23‑655 (the paragraphfour.com answer PDFs I located — e.g., dedc22cv1596A, dedc23cv0327A — are Apotex answers in Bayer/Janssen cases, not this one), which is the filing that would ordinarily carry the full defense caption block and any non‑Delaware "of counsel" names. That document is the single best next source for confirming the complete defense team in this case.

Practical takeaway

For this case, attribute the Apotex defense to Kenneth L. Dorsney and Cortlan S. Hitch of Morris James LLP (Wilmington, Delaware) as Delaware counsel of record. Treat Katten Muchin Rosenman as the likely national/lead counsel by pattern (Apotex's standard Delaware pairing) but label it unverified for 23‑655 pending the answer/counterclaim signature block or a PACER appearance query. Note the prior section's assertion that Apotex's filings appear under Cortlan Hitch — that is confirmed by the docket‑derived record and is not contradicted.