Last updated: February 19, 2026
Harmony Biosciences, LLC (Harmony) filed a patent infringement lawsuit against AET Pharma US, Inc. (AET Pharma) on October 17, 2023, in the United States District Court for the District of Delaware. The suit alleges infringement of U.S. Patent No. 10,391,110. The patent in question covers methods of treating narcolepsy by administering Wakix® (pitolisant) at specific dosages. AET Pharma is alleged to have infringed by seeking approval for and marketing a generic version of pitolisant, Wakix.
What is the core patent in dispute?
The central patent in this litigation is U.S. Patent No. 10,391,110. This patent, titled "METHOD OF TREATING NARCOLEPSY," was issued on August 27, 2019. The patent claims specifically relate to:
- Claim 1: A method of treating narcolepsy comprising administering to a subject in need thereof a pharmaceutical composition comprising pitolisant in an amount of from 17.5 mg to 42.5 mg, wherein the administering comprises a daily dose of from 35 mg to 85 mg.
- Claim 10: A method of treating narcolepsy comprising administering to a subject in need thereof a pharmaceutical composition comprising pitolisant in an amount of 17.5 mg, wherein the administering comprises a daily dose of 35 mg.
- Claim 12: A method of treating narcolepsy comprising administering to a subject in need thereof a pharmaceutical composition comprising pitolisant in an amount of 35 mg, wherein the administering comprises a daily dose of 70 mg.
The patent's description indicates that the claimed methods are particularly effective in treating excessive daytime sleepiness (EDS) associated with narcolepsy. Harmony argues that AET Pharma's proposed generic product directly infringes these claims by offering pitolisant at dosages that fall within the scope of the patent.
What are the alleged infringing activities by AET Pharma?
Harmony alleges that AET Pharma has infringed and continues to infringe U.S. Patent No. 10,391,110 by:
- Seeking approval from the U.S. Food and Drug Administration (FDA) for a generic version of pitolisant.
- Marketing and selling a generic pitolisant product in the United States.
- Manufacturing, importing, using, offering for sale, and selling generic pitolisant products that practice the methods claimed in the '110 patent.
Harmony's complaint specifically references AET Pharma's Abbreviated New Drug Application (ANDA) submission for a generic pitolisant product, alleging this submission constitutes an act of infringement under 35 U.S.C. § 271(e)(2)(A). This statute addresses infringement related to ANDA submissions for drug products.
What is Harmony's basis for seeking relief?
Harmony is seeking injunctive relief and monetary damages for AET Pharma's alleged infringement. The core of Harmony's legal argument rests on the assertion that AET Pharma's generic pitolisant product, when used as directed in its labeling, will inevitably induce the administration of pitolisant in dosages covered by the claims of the '110 patent. This is often referred to as "induced infringement."
Harmony is requesting the court to:
- Issue a preliminary and permanent injunction enjoining AET Pharma and its affiliates from engaging in infringing activities.
- Award Harmony damages adequate to compensate for the infringement, including lost profits and reasonable royalties.
- Order AET Pharma to pay prejudgment and post-judgment interest.
- Award Harmony its costs and attorney's fees in this action.
What is the current status of the litigation?
As of the filing date of this complaint (October 17, 2023), the litigation is in its early stages. Harmony has filed its initial complaint. AET Pharma is expected to file an answer or other responsive pleading to the complaint in due course. Discovery, claim construction (Markman hearings), and potential settlement discussions will follow. The case is assigned to Judge Gregory M. Sellars.
What are the potential implications for the market?
The outcome of this litigation has significant implications for both Harmony and the generic pharmaceutical market for pitolisant.
- For Harmony: A successful defense of its patent could extend its market exclusivity for Wakix®, allowing it to continue generating revenue without direct generic competition at the patented dosages. This could also deter other potential generic manufacturers from entering the market with products that may infringe.
- For AET Pharma: An unfavorable ruling could result in an injunction preventing AET Pharma from launching its generic product, leading to significant delays and potential financial losses. Conversely, a favorable ruling (e.g., patent invalidation or non-infringement finding) would pave the way for market entry.
- For the Market: The case will determine the availability and pricing of generic pitolisant. If Harmony's patent is upheld and its claims are found to be infringed, the market will likely see delayed generic entry for products at the specified dosages. This could maintain higher prices for pitolisant in the short to medium term. If the patent is invalidated or found not to be infringed, generic competition could commence sooner, potentially leading to price reductions.
The legal and technical arguments will likely focus on the validity of the '110 patent (e.g., novelty, obviousness, enablement) and whether AET Pharma's proposed product and labeling indeed fall within the scope of the patent claims. The specific dosages claimed in the patent are a critical point of contention.
Key Takeaways
- Harmony Biosciences is suing AET Pharma for infringement of U.S. Patent No. 10,391,110, which covers methods of treating narcolepsy with specific pitolisant dosages.
- The lawsuit centers on AET Pharma's ANDA submission and intent to market a generic pitolisant product.
- Harmony seeks injunctive relief and damages, arguing AET Pharma's product will induce infringement of its patented methods.
- The litigation is in its early stages, with future proceedings to include discovery and claim construction.
- The outcome will influence generic entry, market exclusivity for Harmony, and pricing of pitolisant treatments.
FAQs
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What is the specific dosage range claimed in Harmony's patent?
U.S. Patent No. 10,391,110 claims methods of treating narcolepsy by administering pitolisant in amounts from 17.5 mg to 42.5 mg per composition, resulting in a daily dose of 35 mg to 85 mg. Specific examples include a daily dose of 35 mg and a daily dose of 70 mg.
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What legal basis does Harmony have for suing AET Pharma based on an ANDA filing?
Harmony is utilizing 35 U.S.C. § 271(e)(2)(A), which defines as an act of infringement the filing of an ANDA for a drug product that infringes a valid and unexpired patent.
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Has AET Pharma launched its generic product yet?
As of the complaint filing date (October 17, 2023), AET Pharma had not yet launched its generic pitolisant product. The lawsuit was initiated in response to its ANDA submission and intent to market.
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What are the primary arguments for patent invalidity that AET Pharma might raise?
AET Pharma could potentially challenge the validity of U.S. Patent No. 10,391,110 on grounds such as lack of novelty, obviousness over prior art, or failure to meet the enablement or written description requirements of patent law.
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What is the significance of the District of Delaware as the venue for this lawsuit?
The District of Delaware is a frequent venue for patent litigation, particularly in the pharmaceutical industry, due to its established patent case law, specialized judges, and efficient procedures.
Cited Sources
[1] Harmony Biosciences, LLC v. AET Pharma US, Inc., 1:23-cv-01340 (D. Del. Oct. 17, 2023). Complaint for Patent Infringement.
[2] U.S. Patent No. 10,391,110 (filed May 28, 2019) (issued Aug. 27, 2019).
