DCT

1:26-cv-01191

Harmony Biosciences Management Inc v. AET Pharma US Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-01191, D. Del., 09/23/2026
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because several defendant entities are incorporated in Delaware, and all defendants allegedly intend to market and sell the accused products in the state, establishing systematic contacts.
  • Core Dispute: Plaintiffs allege that the process Defendants will use to manufacture the active pharmaceutical ingredient for their proposed generic version of the drug WAKIX® will infringe a patent covering a specific, safer method of chemical synthesis.
  • Technical Context: The technology relates to commercial-scale manufacturing processes for pitolisant hydrochloride, the active ingredient in a drug used to treat narcolepsy, focusing on methods that avoid hazardous reagents and minimize impurities.
  • Key Procedural History: This lawsuit is a declaratory judgment action filed under the Hatch-Waxman Act following Defendants' submission of an Abbreviated New Drug Application (ANDA). The complaint references prior litigation between the parties involving other patents on the same drug, and indicates that evidence from a trial in that earlier case, specifically summaries from the Defendants' ANDA, forms a basis for the current infringement allegations.

Case Timeline

Date Event
2021-06-07 '788 Patent Priority Date
2023-10-14 AET sends first Paragraph IV Notice Letter to Harmony for other patents
2023-11-21 Prior litigation filed regarding other patents
2024-04-02 U.S. Patent No. 11,945,788 Issued
2024-08-07 AET sends second Paragraph IV Notice Letter to Harmony
2026-01-11 Novitium grants Harmony an exclusive license to the '788 Patent
2026-09-23 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,945,788 - "Process for Preparing Pitolisant Hydrochloride and Solid-State Forms Thereof"

  • Patent Identification: U.S. Patent No. 11,945,788, "Process for Preparing Pitolisant Hydrochloride and Solid-State Forms Thereof," issued April 2, 2024.

The Invention Explained

  • Problem Addressed: The patent's background section describes prior art processes for manufacturing pitolisant that utilized sodium hydride (NaH), a reagent identified as "hazardous and pyrophoric" and thus "not suitable for a commercial scale" '788 Patent, col. 3:10-15 These prior methods also allegedly produced "deschloro" impurities that were cumbersome to remove '788 Patent, col. 3:18-25
  • The Patented Solution: The invention provides an improved, multi-step process for preparing pitolisant that explicitly avoids the use of sodium hydride '788 Patent, claim 1 The process involves synthesizing a key intermediate, 3-(4-chlorophenyl)-propanol, through a pathway designed to avoid deschloro impurities, and then reacting it with other compounds using a base that is expressly "not sodium hydride" to produce pitolisant, which is subsequently converted to its hydrochloride salt '788 Patent, col. 4:10-35 '788 Patent, claim 1
  • Technical Importance: The patented process purports to offer a commercially suitable and non-hazardous method for preparing pitolisant hydrochloride, a key objective for large-scale pharmaceutical manufacturing '788 Patent, col. 3:47-52

Key Claims at a Glance

  • The complaint asserts infringement of at least Claim 1 of the '788 Patent Compl. ¶91
  • Independent Claim 1 is a process claim comprising the essential elements:
    • a) providing 3-(4-chlorophenyl)-propionic acid;
    • b) converting the acid to its acid chloride or acid anhydride form;
    • c) reducing the resulting compound to obtain 3-(4-chlorophenyl)-propanol (Formula-V);
    • d) treating the Formula-V compound with an activating group to obtain a compound of Formula-(III);
    • e) reacting 3-(piperidin-1-yl)propan-1-ol with the Formula-(III) compound in the presence of a solvent and a base, with the express condition that the base is not sodium hydride, to obtain pitolisant;
    • f) optionally treating the pitolisant with an acid to form a salt; and
    • g) converting the pitolisant or its salt to a pharmaceutically acceptable salt or solid-state form.
  • The complaint notes that triethylamine, a base explicitly recited in dependent claim 7, is identified as a residual solvent in the accused process Compl. ¶63

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are the "AET ANDA Products," which are generic pitolisant hydrochloride tablets (4.45 mg and 17.8 mg) described in ANDA No. 218892 Compl. ¶1

Functionality and Market Context

  • The infringement allegation centers on the process used to manufacture the active pharmaceutical ingredient (API), pitolisant hydrochloride, for the AET ANDA Products Compl. ¶55 The complaint alleges, based on documents from a prior trial, that the manufacturing process described in the Defendants' ANDA corresponds to the process claimed in the '788 Patent Compl. ¶¶59-63 The complaint references a document from the ANDA's Common Technical Document (CTD) which allegedly identifies key starting materials, intermediates, and residual solvents that align with the patented process Compl. ¶62 These products, if approved, would be marketed as generic versions of WAKIX® for the treatment of excessive daytime sleepiness in patients with narcolepsy Compl. ¶57

IV. Analysis of Infringement Allegations

The complaint alleges that the process for manufacturing the pitolisant hydrochloride drug substance for the AET ANDA Products infringes the '788 Patent under 35 U.S.C. § 271(g) Compl. ¶91 The infringement theory is based on evidence from a prior trial, which included a CTD summary (PTX-260) from the Defendants' ANDA Compl. ¶¶59-62 The complaint describes how information from this summary, such as identified starting materials, intermediates, and residual solvents, maps onto the steps of the patented process.

11,945,788 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a) providing 3-(4-chlorophenyl)-propionic acid of Formula-(IV)... The complaint alleges that a technical document from the defendants' ANDA identifies 3-(4-chlorophenyl)propionic acid as the "Starting material of key starting material." ¶62 col. 12:44-48
b) converting... Formula-(IV) to its acid chloride... or acid anhydride... c) reducing acid chloride... to obtain 3-(4-chlorophenyl)-propanol of Formula-(V)... The ANDA document allegedly identifies 3-(4-chlorophenyl)propan-1-ol as a "key starting material," which the complaint asserts corresponds to the product of this multi-step conversion. ¶62 col. 12:1-5
d) treating compound of formula (V) with activating group to obtain a compound of formula (III); The complaint asserts that the ANDA document identifies 3-(4-chlorophenyl)propyl methanesulfonate as a "potential process impurity," which corresponds to the compound of Formula-(III). ¶62 col. 4:16-20
e) reacting 3-(piperidin-1-yl)propan-1-ol with Formula-(III)... in presence of a... base to obtain pitolisant; with the proviso that the base... is not sodium hydride; The ANDA document is alleged to identify 3-(piperidin-1-yl)propan-1-ol as an "In-situ intermediate" and to list triethylamine, a base other than sodium hydride, among the residual solvents. ¶62; ¶63 col. 5:21-29
g) converting pitolisant... to pharmaceutically acceptable salt... The final AET ANDA Products are alleged to comprise pitolisant hydrochloride, the hydrochloride salt of pitolisant. ¶58; ¶63 col. 4:30-35
  • Identified Points of Contention:
    • Evidentiary Questions: A primary issue will be whether the evidence cited in the complaint—namely, the identification of certain chemicals as starting materials, intermediates, impurities, and residual solvents in an ANDA summary document—is sufficient to prove that Defendants' manufacturing process performs the specific sequence of steps recited in claim 1. The complaint invokes 35 U.S.C. § 295, which may create a presumption that the patented process was used, raising the question of whether Plaintiffs have met the statute's "substantial likelihood" threshold Compl. ¶94
    • Technical Questions: What level of correspondence is required between the chemicals identified in the ANDA and the claimed process steps? For example, does the identification of a compound as a "potential process impurity" Compl. ¶62 definitively prove that it was created as an intermediate via the patented pathway? Similarly, does the presence of triethylamine as a "residual solvent" Compl. ¶63 prove it was used as the "base" in the specific reaction of step (e), as required by the claim?

V. Key Claim Terms for Construction

  • The Term: "base ... is not sodium hydride"

  • Context and Importance: This negative limitation is central to the patent's assertion of novelty over prior art that used the hazardous reagent sodium hydride. Infringement requires proof that the accused process uses a "base" and that this base is something other than sodium hydride. The complaint alleges the presence of triethylamine, which would satisfy this limitation if it is found to be the base used in the claimed step Compl. ¶63

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The term "base" is a fundamental term in chemistry. Parties may argue it should be given its plain and ordinary meaning, covering any suitable organic or inorganic substance that can function as a base in the context of the reaction.
    • Evidence for a Narrower Interpretation: The patent provides a list of suitable organic and inorganic bases, including sodium hydroxide, potassium carbonate, and triethylamine '788 Patent, col. 5:21-29 A party could argue that the term should be construed in light of these examples, potentially limiting its scope to bases with similar chemical properties or functions in this specific synthesis.

  • The Term: "converting"

  • Context and Importance: This verb appears in multiple steps of claim 1 (e.g., "converting 3-(4-chlorophenyl)-propionic acid..."). The dispute may focus on whether the specific series of reactions used in the accused process, even if achieving the same end result, constitutes "converting" as understood in the context of the patent.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A party might argue "converting" simply means transforming a starting material into an end product, allowing for variations in intermediate steps, reagents, or reaction conditions not explicitly recited in the claim.
    • Evidence for a Narrower Interpretation: The patent describes a specific sequence of steps (a through g). A party could argue that "converting" implies performing a particular type of chemical transformation as part of this claimed sequence, and that a process using a fundamentally different chemical pathway would not meet this limitation.

VI. Other Allegations

  • Indirect Infringement: The complaint's primary infringement allegation is direct infringement under 35 U.S.C. § 271(g), which makes it an act of infringement to import, sell, or use a product within the United States that was made by a process patented in the United States Compl. ¶91
  • Willful Infringement: The complaint alleges that Defendants have "actual knowledge of the '788 Patent" and are aware that their activities would constitute infringement Compl. ¶95 It further requests a declaration that the case is "exceptional" and an award of attorneys' fees under 35 U.S.C. § 285, which is consistent with an allegation of willful or egregious infringement behavior Compl. ¶98

VII. Analyst’s Conclusion: Key Questions for the Case

This case appears to present two central questions for the court's determination:

  1. A core issue will be one of evidentiary sufficiency: Is the circumstantial evidence presented—the identification of specific starting materials, impurities, and residual solvents in the Defendants' ANDA documentation—enough to establish by a preponderance of the evidence that the accused manufacturing process practices each step of the patented method? The applicability and effect of the statutory presumption under 35 U.S.C. § 295 will be a critical factor in this analysis.

  2. A key legal question will be one of claim scope and interpretation: How will the court construe the term "base... is not sodium hydride"? The case may hinge on whether the evidence of residual triethylamine is sufficient to prove its use as the "base" in the specific reaction claimed, thereby satisfying a crucial limitation that distinguishes the patented invention from the prior art.