Merck v. Apotex Inc. et al.

This patent infringement litigation, Merck v. Apotex Inc. et al., involves pharmaceutical giant Merck KGaA and its subsidiaries against generic drug manufacturer Apotex Inc. and its affiliate. The plaintiff, Merck KGaA (a German multinational operating as "Merck KGaA, Darmstadt, Germany" in the U.S.), alongside its subsidiaries Merck Serono SA and Ares Trading SA, is a global pharmaceutical leader that develops innovative medicines and vaccines. The defendants, Apotex Inc. (a Canadian corporation) and Apotex Corp. (its U.S. affiliate), are among North America's largest generic pharmaceutical manufacturers, known for actively challenging brand-name drug patents to bring affordable generic medications to market.

The dispute centered on Apotex's Abbreviated New Drug Application (ANDA) seeking approval to market a generic version of cladribine, a drug used to treat multiple sclerosis, prior to the expiration of Merck's patents. Merck's brand name product for cladribine is Mavenclad®. The asserted patents included U.S. Patent No. 8,377,903, entitled "Cladribine Regimen for Treating Multiple Sclerosis," which broadly covers the use of multiple doses of cladribine for treating multiple sclerosis, particularly relapsing-remitting or early secondary progressive forms, and improved oral dosing regimens aimed at reducing adverse effects. Also at issue were U.S. Patent No. 7,713,947 and U.S. Patent No. 10,849,919, both claiming specific cladribine dosing regimens for multiple sclerosis.

Initially litigated in the U.S. District Court for the District of Delaware, this Hatch-Waxman case saw judgment entered entirely in favor of Apotex. The case was ultimately decided by the U.S. Court of Appeals for the Federal Circuit, which entered judgment on February 2, 2026, affirming the invalidity of claims 17, 19, 20, and 22–27 of the '903 patent (among others) as obvious, and dismissing all of Merck's infringement claims. The Federal Circuit's role as the exclusive appellate court for patent cases makes its rulings on obviousness, particularly for method-of-treatment claims in pharmaceuticals, highly influential. The case is notable for reinforcing the vulnerability of method-of-treatment claims, especially those built on known compounds with incremental dosing modifications, to obviousness challenges. Furthermore, parallel inter partes review (IPR) proceedings, such as those filed by Hopewell Pharma Ventures challenging Merck's cladribine patents, played a significant role, with the Federal Circuit affirming the PTAB's invalidity findings in related cases, which ultimately impacted the outcome of this litigation.

The patent infringement litigation Merck v. Apotex Inc. et al. concerning U.S. Patent No. 8,377,903, along with U.S. Patent Nos. 7,713,947 and 10,849,919, concluded with a judgment entirely in favor of Apotex. The asserted claims of the '903 patent (claims 17, 19, 20, and 22–27) and the '947 patent (claims 36, 38, 39, and 41–46) were declared invalid as obvious, and Merck's infringement claims were dismissed.

Here's a chronological overview of the key legal developments and outcome:

Filing & Initial Pleadings

• Complaint Filed (2023-06-15): Merck KGaA, Merck Serono SA, and Ares Trading SA (collectively, "Merck") filed a patent infringement complaint against Apotex Inc. and Apotex Corp. (collectively, "Apotex") in the U.S. District Court for the District of Delaware, designated as Case No. 1:23-cv-00655-GBW-CJB. The action arose from Apotex's submission of Abbreviated New Drug Application (ANDA) No. 218425 to the FDA, seeking approval to market a generic version of Merck's MAVENCLAD® (cladribine) product prior to the expiration of the asserted patents. Merck alleged infringement of claims 36, 38, 39, and 41-46 of the '947 patent, claims 17, 19, 20, and 22-27 of the '903 patent, and claims of the '919 patent.
• Apotex's Answer and Counterclaims (2023-10-03): Apotex filed its Answer and Counterclaims, admitting to filing ANDA No. 218425 with a Paragraph IV certification for the '947 and '903 patents. Apotex denied infringement and asserted that the '947 and '903 patents were invalid. Apotex also noted a pending motion to dismiss related to the '919 patent.

Pre-Trial Motions of Substance

• Motion to Stay Pending IPR (Granted 2024-12-23; Global Stay 2025-01-16): Defendant Hopewell Pharma Ventures (a defendant in a related consolidated case, 1:22-cv-01365) filed an emergency motion to stay the case pending resolution of appeals of Inter Partes Review (IPR) proceedings. The court granted Hopewell's motion on December 23, 2024, and subsequently ordered a global stay of Merck's action against all remaining defendants, including Apotex, on January 16, 2025. Apotex had opposed a global stay without provisos, specifically requesting that its 30-month statutory stay from FDA approval not be tolled or extended. The court explicitly stated that the global stay would not toll the Apotex Defendants' thirty-month statutory stay.

Claim Construction (Markman)

• Markman Hearing (2024-01-30): The court conducted a Markman hearing on January 30, 2024. The sole dispute between the parties during claim construction was whether the total dose of cladribine administered during the induction and maintenance periods could be the same (as proposed by Merck) or if the maintenance period dose must always be lower than the induction period dose (as argued by Apotex).
• Claim Construction Order (2024-06-13): The court issued a Memorandum Order on claim construction on June 13, 2024.

Parallel PTAB IPR Proceedings

• IPR Filings (2022-11-22): Inter Partes Review (IPR) proceedings were filed against U.S. Patent No. 8,377,903, including IPR2023-00050 by TWI Pharmaceuticals, Inc., and IPR2023-00480 and IPR2023-00481 by Hopewell Pharma Ventures. These IPRs challenged claims of U.S. Patent Nos. 7,713,947 and 8,377,903, both related to cladribine regimens for treating multiple sclerosis, on obviousness grounds.
• PTAB Final Written Decisions (Undated, prior to Oct. 2024): The Patent Trial and Appeal Board (PTAB) issued final written decisions invalidating all challenged claims of U.S. Patent No. 7,713,947 and U.S. Patent No. 8,377,903 as obvious.
• Federal Circuit Affirmance of PTAB Rulings (2025-10-30): The Federal Circuit affirmed the PTAB's decisions, finding the claims of the '947 and '903 patents unpatentable as obvious. Specifically, in Merck Serono S.A. v. Hopewell Pharma Ventures, Inc. (Case No. 25-1210) and Merck Serono S.A. v. TWi Pharms., Inc. (Case No. 25-1464), the Federal Circuit upheld the PTAB's findings, clarifying the "by another" prior art standard under pre-AIA § 102(e) and concluding that the asserted cladribine dosing claims would have been obvious.

Final Disposition

• Judgment in District Court (2026-02-02): Following the Federal Circuit's mandate (entered on January 29, 2026) in related IPR appeals (Nos. 2025-1210 and 2025-1211, referring to the Hopewell Federal Circuit appeal), the district court entered final judgment entirely in favor of Apotex Inc. and Apotex Corp. on February 2, 2026. Claims 17, 19, 20, and 22–27 of the '903 patent and claims 36, 38, 39, and 41–46 of the '947 patent were declared invalid as obvious. All of Merck's infringement claims were dismissed, with no damages awarded.
• Federal Circuit Termination (2026-02-02): The Federal Circuit case itself, Merck v. Apotex Inc. et al. (which appears to be the direct appeal from the district court judgment, or the final action concluding the litigation in light of the IPR outcomes), was terminated on February 2, 2026, with a judgment in favor of Apotex. This final judgment aligns with the Federal Circuit's earlier affirmance of the PTAB's obviousness rulings for the patents at issue.

Counsel of Record for Plaintiff Merck in Merck v. Apotex Inc. et al.

In the patent infringement case of Merck v. Apotex Inc. et al., terminated on February 2, 2026, the plaintiff, Merck (specifically Merck KGaA, Merck Serono SA, and Ares Trading SA), was represented by the following counsel:

From Quinn Emanuel Urquhart & Sullivan, LLP:

• Name: Nick Cerrito
  • Role: Attorney for Plaintiff(s)
  • Firm & Office: Quinn Emanuel Urquhart & Sullivan, LLP (Specific office location not detailed in immediate search results for this case, but firm has multiple US offices, including New York and Silicon Valley)
  • Experience Note: Recognized as a "Best Lawyer in America" for Intellectual Property Litigation and Patent Litigation (2016-2022).
• Name: Victoria Maroulis
  • Role: Attorney for Plaintiff(s)
  • Firm & Office: Quinn Emanuel Urquhart & Sullivan, LLP (Specific office location not detailed in immediate search results for this case)
  • Experience Note: Recognized as a "Best Lawyer in America" for Intellectual Property Litigation and Patent Litigation (2016-2022) and named among "Top 250 Women in IP" by Managing IP (2021/22).
• Name: Robert Wilson
  • Role: Attorney for Plaintiff(s)
  • Firm & Office: Quinn Emanuel Urquhart & Sullivan, LLP (Specific office location not detailed in immediate search results for this case)
  • Experience Note: Recognized as a "Best Lawyer in America" for Intellectual Property Litigation and Patent Litigation (2016-2022).

From Williams & Connolly LLP:

• Name: Not explicitly named in the complaint as signatory, but Williams & Connolly LLP is identified as counsel for Merck in various patent litigations. Their website mentions representing Merck in patent litigation concerning its diabetes drug Januvia and defending patent litigation related to Keytruda.

In-house Counsel (from older related Merck cases, specific to this case not identified):

• In earlier, distinct Federal Circuit cases involving Merck and Apotex (e.g., concerning patents 4,797,413, 6,248,735, and 6,316,443, decided in 2008), Edward W. Murray and Karen M. Stoffan, both of Merck & Co., Inc. in Rahway, New Jersey, were listed as "of counsel on the brief" for Merck. However, it is important to note that these individuals and their roles are tied to prior, distinct litigation and are not confirmed for the 2026 terminated case involving the '903 patent.
• Another prior case from 2007 listed Paul D. Matukaitis, Merck & Company, of Whitehouse Station, New Jersey, and Edward W. Murray, Merck & Company, of Rahway, New Jersey, as in-house counsel for Merck. Again, these roles are not confirmed for the 2026 case.

The complaint initiating the lawsuit that led to this Federal Circuit appeal, filed in the District of Delaware (C.A. No. ______, filed June 15, 2023), lists Quinn Emanuel Urquhart & Sullivan, LLP as the attorneys for the plaintiffs, Merck KGaA, Merck Serono SA, and Ares Trading SA. Merck is known to be a frequent participant in pharmaceutical patent litigation, often engaging firms with deep experience in Hatch-Waxman cases.

The defendant(s) in Merck v. Apotex Inc. et al., Apotex Inc. and Apotex Corp., achieved a favorable judgment at the Federal Circuit, which affirmed the invalidity of Merck's patents as obvious and dismissed all infringement claims on February 2, 2026. This outcome was significantly influenced by related inter partes review (IPR) proceedings and their subsequent appeals to the Federal Circuit.

While the specific Federal Circuit opinion for Merck v. Apotex Inc. et al. that was terminated on February 2, 2026, does not appear directly in public search results with named counsel for Apotex, the provided information explicitly states that "The Federal Circuit's controlling decision in Merck Serono v. Hopewell established that the asserted cladribine dosing claims would have been obvious to a person of ordinary skill in the art at the time of invention." Furthermore, Merck Serono S.A. v. TWi Pharmaceuticals, Inc. (Nos. 25-1463, 25-1464, Fed. Cir. Oct. 30, 2025) was a companion case with a similar outcome affirming obviousness. It is highly probable that Apotex relied on the outcomes of these IPR appeals to secure its victory in the direct infringement case.

Based on the publicly available information for these related Federal Circuit appeals, the counsel representing the parties whose efforts led to the invalidation of Merck's patents, thereby benefiting Apotex, include:

*For Hopewell Pharma Ventures, Inc. (Appellee in Merck Serono S.A. v. Hopewell Pharma Ventures, Inc.):*

• John Christopher Rozendaal (Lead Counsel)
  • Firm: Sterne Kessler Goldstein & Fox PLLC (Washington, DC)
  • Note: Specializes in patent litigation, particularly Hatch-Waxman and inter partes review proceedings, with extensive experience representing generic pharmaceutical companies.
• Christina Elizabeth Dashe (Counsel)
  • Firm: Sterne Kessler Goldstein & Fox PLLC
  • Note: Practicing in patent litigation and inter partes review.
• Eldora Ellison (Counsel)
  • Firm: Sterne Kessler Goldstein & Fox PLLC
  • Note: Focuses on patent litigation and strategic patent counseling, especially in the pharmaceutical and biotechnology sectors.
• Tyler Liu (Counsel)
  • Firm: Sterne Kessler Goldstein & Fox PLLC
  • Note: Involved in patent litigation and IPRs, particularly concerning chemical and pharmaceutical technologies.
• Olga Partington (Counsel)
  • Firm: Sterne Kessler Goldstein & Fox PLLC
  • Note: Experience in patent litigation and inter partes review.
• Chandrika Vira (Counsel)
  • Firm: Sterne Kessler Goldstein & & Fox PLLC
  • Note: Practices in patent litigation and IPR proceedings, often in the biotechnology and pharmaceutical fields.

*For TWi Pharmaceuticals, Inc. (Successful Defender in Merck Serono, S.A. v. TWi Pharmaceuticals, Inc.):*

• Philip Segrest (Lead Counsel)
  • Firm: Husch Blackwell (Office location not specified in snippet, but Husch Blackwell has various offices)
  • Note: Partner at Husch Blackwell, successfully defended TWi Pharmaceuticals in this Hatch-Waxman litigation.
• Don Mizerk (Counsel)
  • Firm: Husch Blackwell (Office location not specified)
  • Note: Partner at Husch Blackwell, part of the trial team that secured the Federal Circuit victory for TWi Pharmaceuticals.
• Steve Howe (Counsel)
  • Firm: Husch Blackwell (Office location not specified)
  • Note: Partner at Husch Blackwell, played a role in the successful defense of TWi Pharmaceuticals in this case.

These firms and attorneys played a direct role in the Federal Circuit decisions that invalidated Merck's cladribine patents, which in turn led to the judgment in favor of Apotex in the infringement case.