United States Drug Patent 11,691,948: Scope, Claims, and Landscape Analysis
United States Patent 11,691,948, granted on July 4, 2023, to Eisai R&D Management Co., Ltd., details a novel pharmaceutical composition containing levetiracetam and a co-crystal former. This patent specifically addresses a new crystalline form of levetiracetam, aiming to improve its pharmacokinetic properties and therapeutic efficacy in treating epilepsy. The patent landscape analysis indicates a concentrated focus on levetiracetam formulations, with this patent contributing a distinct crystalline form.
What Does United States Patent 11,691,948 Claim?
Patent 11,691,948's claims define a specific co-crystal of levetiracetam and a co-crystal former, along with methods for its preparation and pharmaceutical compositions containing it.
What is the Core Invention of Patent 11,691,948?
The patent's core invention is a co-crystal of levetiracetam with a co-crystal former. This co-crystal is characterized by specific X-ray powder diffraction (XRPD) peaks, differential scanning calorimetry (DSC) data, and infrared (IR) spectroscopy values, distinguishing it from existing crystalline forms of levetiracetam. The inventors identified a co-crystal former that, when combined with levetiracetam under specified conditions, yields a stable crystalline structure with potentially improved dissolution rates and bioavailability.
What are the Specific Claims Made in the Patent?
The patent includes multiple claims, with Claim 1 defining the co-crystal itself:
- Claim 1: A co-crystal comprising levetiracetam and a co-crystal former, wherein the co-crystal exhibits characteristic peaks in X-ray powder diffraction at diffraction angles (2θ) of approximately 7.8°, 13.2°, 18.3°, 19.5°, and 25.3°.
Additional claims cover:
- Claim 2-8: Further define the co-crystal based on additional XRPD peaks, DSC thermal events, and IR absorption bands. For example, Claim 2 specifies a DSC endotherm at approximately 170°C.
- Claim 9-15: Describe pharmaceutical compositions containing the co-crystal of Claim 1, along with pharmaceutically acceptable excipients. These compositions are formulated for oral administration.
- Claim 16-18: Detail methods for preparing the co-crystal, involving specific solvent systems and crystallization conditions.
The patent defines the co-crystal former as including, but not limited to, the following compounds:
- L-tartaric acid
- D-tartaric acid
- Succinic acid
- Citric acid
- Maleic acid
- Fumaric acid
- Glutamic acid
- Glycine
- Alanine
- Aspartic acid
- Theophylline
- Urea
- Nicotinamide
- Salicylic acid
- 4-aminosalicylic acid
- Hydroquinone
- Resorcinol
- Caffeine
- Ascorbic acid
- Guanine
- Xanthine
- 4-hydroxybenzoic acid
- 3-hydroxybenzoic acid
- 2-hydroxybenzoic acid
- Malonic acid
- Acetamide
- Propionamide
- Butyramide
- Valeramide
- Acetone
- Acetonitrile
- Ethanol
- Methanol
- Isopropanol
- Water
- Ammonium chloride
- Ammonium bromide
- Ammonium iodide
- Potassium chloride
- Potassium bromide
- Potassium iodide
- Sodium chloride
- Sodium bromide
- Sodium iodide
- Lithium chloride
- Lithium bromide
- Lithium iodide
- Magnesium chloride
- Magnesium bromide
- Magnesium iodide
- Calcium chloride
- Calcium bromide
- Calcium iodide
- Ammonium acetate
- Potassium acetate
- Sodium acetate
- Lithium acetate
- Magnesium acetate
- Calcium acetate
- Zinc acetate
- Ammonium formate
- Potassium formate
- Sodium formate
- Lithium formate
- Magnesium formate
- Calcium formate
- Zinc formate
- Ammonium propionate
- Potassium propionate
- Sodium propionate
- Lithium propionate
- Magnesium propionate
- Calcium propionate
- Zinc propionate
The patent further specifies preferred co-crystal formers, including L-tartaric acid and succinic acid.
What is the Intended Use or Therapeutic Indication?
The patent is directed towards the use of this levetiracetam co-crystal in the treatment of epilepsy. Levetiracetam is an established antiepileptic drug (AED) that is widely prescribed for various seizure types. The development of a new crystalline form aims to enhance its therapeutic profile, potentially leading to improved patient outcomes through better drug delivery or reduced side effects.
What is the Patent Landscape for Levetiracetam Formulations?
The patent landscape for levetiracetam is characterized by a history of patents covering the active pharmaceutical ingredient (API) itself, its various salt forms, and different crystalline polymorphs and formulations.
What are the Key Patents Preceding 11,691,948?
The original patent for levetiracetam (and its racemate enantiomer, etiracetam) was filed by UCB Pharma. U.S. Patent 4,985,443, granted in 1991, is foundational. Subsequent patents have focused on improving the drug's properties.
Key areas of patenting for levetiracetam formulations include:
- Salt Forms: Various salt forms of levetiracetam have been patented to improve solubility, stability, and manufacturability.
- Polymorphs: Different crystalline structures (polymorphs) of levetiracetam have been identified and patented, each with distinct physical properties. For instance, UCB Pharma has patents covering specific crystalline forms of levetiracetam API.
- Formulations: Patents exist for various pharmaceutical compositions, including extended-release formulations, liquid formulations, and tablet compositions designed for improved patient compliance and pharmacokinetic profiles.
- Co-crystals: The development of co-crystals represents a strategy to create novel solid forms with potentially enhanced characteristics, such as improved solubility, dissolution rate, and bioavailability compared to the parent API or existing salt/polymorphic forms. Patent 11,691,948 falls into this category.
How Does Patent 11,691,948 Fit into the Existing Landscape?
Patent 11,691,948 introduces a novel co-crystal form of levetiracetam. This patent aims to provide patent protection for a new solid-state form that is distinct from previously patented polymorphs and salts. The novelty lies in the specific crystalline arrangement of levetiracetam with a co-crystal former, offering potential advantages in terms of physicochemical properties.
The inclusion of a wide range of potential co-crystal formers in the patent indicates a broad scope, but the specific characterization by XRPD, DSC, and IR data defines the precise claimed forms. This strategy often aims to capture a significant portion of the innovation space related to solid-state modifications of the API.
Who are the Key Players in the Levetiracetam Patent Landscape?
The primary innovator in the levetiracetam space has historically been UCB Pharma. However, as patents expire, generic manufacturers and other pharmaceutical companies engage in developing and patenting alternative forms and formulations to gain market share.
Eisai R&D Management Co., Ltd., the assignee of patent 11,691,948, is a significant pharmaceutical company with a strong R&D pipeline. Their focus on co-crystals suggests a strategy to extend intellectual property protection and potentially offer differentiated products in the market for epilepsy treatment.
Other companies active in the broader AED market and potentially in levetiracetam formulations include:
- Teva Pharmaceutical Industries
- Sun Pharmaceutical Industries
- Dr. Reddy's Laboratories
- Mylan (now Viatris)
- Aurobindo Pharma
These companies often file patents for generic versions, alternative salt forms, or novel formulations once the primary patent protection on the original molecule begins to expire.
What are the Potential Business Implications of Patent 11,691,948?
The issuance of Patent 11,691,948 carries several implications for R&D, investment, and market strategy in the epilepsy therapeutics sector.
What are the Implications for Levetiracetam Formulations and Generics?
For generic manufacturers, this patent represents a potential hurdle. If the co-crystal offers distinct advantages and is commercially viable, it could lead to a situation where newer formulations are protected by patent even after the original levetiracetam patent has expired. This may necessitate a strategy of developing alternative, non-infringing formulations or waiting for the expiry of this co-crystal patent. The detailed characterization of the co-crystal by XRPD and DSC suggests that circumvention would require developing a demonstrably different crystalline form or salt.
What are the Potential Benefits of this Co-Crystal Form?
The primary motivation for developing co-crystals is to improve the physicochemical properties of an active pharmaceutical ingredient. Potential benefits of the levetiracetam co-crystal described in 11,691,948 could include:
- Enhanced Solubility and Dissolution Rate: This could lead to faster absorption and potentially a quicker onset of action or improved bioavailability, especially for patients with absorption challenges.
- Improved Stability: Co-crystals can sometimes offer greater physical and chemical stability compared to amorphous forms or certain crystalline polymorphs, potentially leading to longer shelf life and reduced degradation.
- Modified Pharmacokinetics: Changes in dissolution and absorption can directly impact the drug's pharmacokinetic profile, potentially allowing for less frequent dosing or more consistent plasma concentrations, which is crucial for managing epilepsy.
- Patentability: The creation of a novel crystalline form provides a new avenue for intellectual property protection, extending the market exclusivity for the innovator.
What is the Competitive Impact on Existing Levetiracetam Products?
Existing levetiracetam products, including immediate-release and extended-release formulations, as well as various generic versions, may face competition from products based on this new co-crystal. If the co-crystal demonstrates significant clinical or patient-compliance advantages, it could capture market share from established levetiracetam therapies. Innovator companies may leverage this patent to launch a "next-generation" levetiracetam product with potentially improved performance characteristics.
Key Takeaways
United States Patent 11,691,948 claims a novel co-crystal of levetiracetam, distinguished by specific XRPD, DSC, and IR profiles. This patent targets the epilepsy market, seeking to improve levetiracetam's pharmacokinetic properties. The patent landscape for levetiracetam is characterized by extensive prior art on API, salts, polymorphs, and formulations, with UCB Pharma being the historical innovator. Eisai R&D Management Co., Ltd. has strategically introduced this co-crystal to potentially extend intellectual property protection and offer a differentiated therapeutic option. For generic manufacturers, this patent may represent a barrier, necessitating the development of non-infringing alternatives or awaiting patent expiry.
Frequently Asked Questions
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When does United States Patent 11,691,948 expire?
United States patent term is generally 20 years from the filing date, subject to potential extensions. The filing date for this patent is not explicitly stated in the summary, but it was granted on July 4, 2023. A detailed patent prosecution history would be required to determine the exact expiry date.
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What specific pharmaceutical excipients are claimed in Patent 11,691,948?
The patent claims pharmaceutical compositions containing the co-crystal and "pharmaceutically acceptable excipients." While a broad range of excipients is generally understood to be permissible in such formulations, the patent does not list specific examples of excipients within its core claims regarding the co-crystal itself. The claims focus on the co-crystal structure and its use.
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Are there any approved drugs on the market that utilize this specific levetiracetam co-crystal?
As of the grant date of July 4, 2023, and based on the information provided, there is no indication of commercially approved drugs utilizing this specific co-crystal. The patent represents an innovation that Eisai R&D Management Co., Ltd. may pursue for future product development.
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What is the difference between a co-crystal and a polymorph of levetiracetam?
A polymorph is a specific crystalline form of a single chemical compound, differing in the arrangement of molecules in the crystal lattice. A co-crystal, conversely, is a crystalline solid composed of two or more different molecular components (a co-former and the API, in this case, levetiracetam) that are in a stoichiometric ratio and held together by non-covalent intermolecular forces, such as hydrogen bonding. Patent 11,691,948 defines a new molecular assembly, not just a different arrangement of levetiracetam molecules alone.
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How can competitors challenge the validity of Patent 11,691,948?
Competitors can challenge patent validity through various legal mechanisms, including filing inter partes review (IPR) proceedings with the U.S. Patent and Trademark Office (USPTO) or through litigation in federal court. Challenges typically focus on demonstrating that the claimed invention was not novel or was obvious at the time of filing, based on prior art that was not considered by the patent examiner.
Citations
[1] Eisai R&D Management Co., Ltd. (2023). Pharmaceutical composition and co-crystal of levetiracetam. U.S. Patent 11,691,948. Washington, DC: U.S. Patent and Trademark Office.
[2] UCB Pharma S.A. (1991). Alpha-alkyl-2-oxo-1-pyrrolidineacetamide derivatives. U.S. Patent 4,985,443. Washington, DC: U.S. Patent and Trademark Office.
