In a swift resolution to a high-stakes pharmaceutical patent dispute, the U.S. District Court for the District of New Jersey entered a consent judgment and permanent injunction on August 1, 2024, in favor of Catalyst Pharmaceuticals, Inc. and SERB SA against Inventia Healthcare Limited. The case, filed November 17, 2023 and resolved in just 258 days, centered on six U.S. patents covering Firdapse® (amifampridine) 10 mg tablets—a critical treatment for Lambert-Eaton myasthenic syndrome (LEMS). The consent judgment bars Inventia from making, selling, or distributing its generic ANDA product (ANDA No. 218760) in the United States without authorization under the Licensed Firdapse Patents.

This case sits at the intersection of Hatch-Waxman ANDA litigation, multi-patent portfolio enforcement, and settlement strategy in the rare-disease pharmaceutical space. Patent attorneys, in-house IP teams, and pharmaceutical R&D leaders should take note: the consent judgment structure here reflects a calculated litigation resolution that preserves patent enforceability while allowing FDA approval proceedings to continue—a pattern with significant implications for ANDA filers and branded pharmaceutical IP strategy alike.

Case Overview

The Parties

The Patents at Issue

The six Licensed Firdapse Patents—US10,626,088; US10,793,893; US11,060,128; US11,268,128; US11,274,331; and US11,274,332—collectively cover compositions, formulations, and methods of treatment involving amifampridine (3,4-diaminopyridine phosphate), the active ingredient in Firdapse®. These patents protect the drug’s specific dosage forms, manufacturing processes, and therapeutic use in treating Lambert-Eaton myasthenic syndrome, a rare autoimmune neuromuscular disorder. Together, they form a dense patent thicket that any generic ANDA filer must navigate to bring a competing product to the U.S. market.

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Legal Representation

Plaintiff Counsel: Gibbons PC; Sterne Kessler Goldstein & Fox (lead: Charles H. Chevalier)
Defendant Counsel: CHIESA SHAHINIAN & GIANTOMASI PC (lead: Michael Cross.)

Litigation Timeline & Procedural History

This case was filed in the U.S. District Court for the District of New Jersey on November 17, 2023—a jurisdiction that is among the most active in the country for Hatch-Waxman pharmaceutical patent litigation, regularly handling complex ANDA disputes given its proximity to major pharmaceutical industry clusters. As a first-instance district court proceeding under the Hatch-Waxman framework, the case triggered a statutory 30-month stay of FDA final approval for Inventia’s ANDA No. 218760, giving Catalyst the structural leverage typical of NDA holder–ANDA filer disputes under 21 U.S.C. § 355(j).

The case resolved in just 258 days—well within the 30-month stay window—via a consent judgment rather than a trial on the merits or motion practice ruling. This rapid resolution strongly suggests that the parties negotiated a private settlement agreement (referenced in the judgment text) providing Inventia with a future authorized entry date or license, while Catalyst and SERB secured an immediate injunction and enforcement mechanism. All claims and counterclaims were dismissed without prejudice and without costs, indicating a negotiated outcome rather than a determination of patent validity or infringement on the facts.

The Verdict & Legal Analysis

Outcome

The District Court of New Jersey entered a consent judgment and permanent injunction on August 1, 2024, enjoining Inventia Healthcare Limited—including its affiliates, successors, and assigns—from infringing the six Licensed Firdapse Patents by making, selling, offering to sell, importing, or distributing its ANDA product in the United States without specific authorization from Catalyst and SERB. No damages were awarded, and all claims and counterclaims were dismissed without prejudice and without costs to any party. Critically, the consent judgment expressly preserves the FDA’s authority to grant final approval to Inventia’s ANDA No. 218760, suggesting a future licensed market entry may have been negotiated in the underlying settlement agreement.

Verdict Cause Analysis

The consent judgment was entered on the basis of a negotiated infringement resolution, with the following key legal and structural grounds governing its terms:

• Inventia’s ANDA No. 218760 was found to implicate all six Licensed Firdapse Patents under the Hatch-Waxman Act’s artificial infringement provisions (35 U.S.C. § 271(e)(2)), giving Catalyst and SERB standing to seek injunctive relief.
• The consent judgment enjoins Inventia from any unauthorized commercial activity relating to its ANDA product in the United States, with enforcement rights expressly assigned to Catalyst, SERB, and their successors or assigns.
• The parties stipulated that the district court retains jurisdiction to enforce or supervise performance under both the consent judgment and the underlying private settlement agreement, preserving a judicial enforcement mechanism post-dismissal.
• All claims and counterclaims—including any invalidity or non-infringement counterclaims Inventia may have asserted—were dismissed without prejudice, meaning patent validity was neither adjudicated nor admitted.

Legal Significance

1. 1. The dismissal of all counterclaims without prejudice means the validity of the six Firdapse patents remains fully intact and uncontested on the record, preserving Catalyst and SERB’s ability to assert the same patents against future ANDA filers without a prior adverse ruling to contend with.
2. 2. The express carve-out preserving FDA authority to grant final ANDA approval signals a likely authorized generic or future-dated license arrangement in the settlement—a structure that ANDA filers and branded companies should model when negotiating Hatch-Waxman consent judgments to avoid triggering antitrust scrutiny.
3. 3. The multi-patent consent judgment covering six related U.S. patents demonstrates the strategic value of building layered patent portfolios around rare-disease drug products, as enforcement of even one patent would have been sufficient to obtain the same injunctive relief—the breadth of the portfolio provided maximum settlement leverage.

Strategic Takeaways

For Patent Attorneys:

• When representing branded pharmaceutical clients in Hatch-Waxman litigation, build consent judgment language that expressly preserves FDA approval authority and retains district court jurisdiction—this protects the settlement’s enforceability without requiring additional litigation.
• Dismissal of counterclaims without prejudice in consent judgments is a critical drafting point: ensure that invalidity and non-infringement defenses are dismissed without prejudice to prevent the defendant from claiming patent admission in future proceedings.
• The six-patent enforcement approach here illustrates the value of prosecuting continuation and related applications to build a portfolio that survives challenge to any single patent—structure prosecution strategy around ANDA vulnerability from the earliest filing stages.
• The retention of district court jurisdiction over settlement agreement performance is a powerful enforcement tool—draft consent judgments to include this provision explicitly so that breach of the settlement agreement can be remedied via contempt rather than a new breach-of-contract action.

For IP Professionals:

• In-house teams at branded pharmaceutical companies should monitor ANDA filings against all patents in their portfolio using FDA Orange Book listings and PACER alerts—Catalyst’s rapid action within days of ANDA certification illustrates how speed in Hatch-Waxman litigation directly determines the length of market exclusivity protection.
• The multi-assignee structure here (Catalyst as NDA holder, SERB SA as co-plaintiff with licensed rights) reflects the importance of clearly documenting co-ownership and licensing arrangements before litigation begins—ambiguity in standing can delay injunctive relief in time-sensitive ANDA disputes.

For R&D Teams:

• Pharmaceutical R&D teams developing generic or biosimilar versions of rare-disease treatments should conduct thorough FTO analysis against both composition-of-matter and method-of-treatment patent families, as the Firdapse portfolio illustrates how a single active ingredient can be encircled by multiple patent layers covering formulation, dosage, and therapeutic use.
• When evaluating ANDA opportunities, assess whether the branded company has a pattern of resolving Hatch-Waxman disputes via consent judgment—this may indicate willingness to negotiate authorized generic arrangements, which could represent a more commercially viable path than full patent challenge litigation.