Last updated: February 19, 2026
This report provides a detailed analysis of Canadian patent CA2649243, focusing on its scope, claims, and the surrounding patent landscape. The patent, filed by Eli Lilly and Company, covers novel insulin glargine formulations and methods of use.
What is the Core Invention of CA2649243?
Canadian patent CA2649243 describes and claims formulations of insulin glargine that exhibit specific storage stability profiles and improved pharmacokinetic (PK) and pharmacodynamic (PD) characteristics. The invention aims to provide a long-acting insulin preparation with predictable glucose-lowering effects.
The primary focus of the patent is on formulations that contain insulin glargine, zinc, and a buffer system that maintains the pH within a specified range. These formulations are designed to prevent the formation of aggregates and to ensure the consistent release of insulin glargine after subcutaneous injection.
Key aspects of the invention include:
- Formulation Composition: Specific concentrations of insulin glargine, zinc ions, and buffering agents. The patent details preferred molar ratios and pH ranges.
- Stabilization Mechanism: The role of zinc in forming hexamers of insulin glargine, which then slowly dissociate into monomers upon injection, leading to prolonged absorption.
- Storage Stability: The formulations are claimed to be stable under specific storage conditions, such as at room temperature, for extended periods without significant degradation or changes in physical properties.
- Pharmacokinetic/Pharmacodynamic Profile: The formulations are designed to achieve a steady basal insulin level over a 24-hour period with a low peak-to-trough ratio, minimizing glycemic fluctuations.
What are the Key Claims of CA2649243?
The patent comprises multiple claims, with the independent claims defining the core of the invention.
Independent Claims:
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Claim 1: This claim typically defines a pharmaceutical composition comprising:
- Insulin glargine.
- Zinc ions.
- A buffering agent that maintains the pH of the composition between 3.5 and 4.5.
- A specific concentration range for insulin glargine and zinc.
- A specified concentration of an isotonic agent.
- Water for injection.
The claim may further specify the molar ratio of insulin glargine to zinc ions.
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Claim 15 (or similar): This claim often relates to a method of treating diabetes mellitus by administering the pharmaceutical composition of claim 1. The method emphasizes achieving a basal insulin level and controlling blood glucose over a 24-hour period.
Dependent Claims:
Dependent claims further refine the scope of the independent claims by adding specific limitations. These can include:
- Specific Buffering Agents: Examples of buffering agents such as citrate or phosphate.
- Concentration Ranges: Narrower ranges for insulin glargine, zinc, or isotonic agents.
- pH Values: More precise pH values within the 3.5 to 4.5 range.
- Isotonic Agents: Specific examples like glycerol or sodium chloride.
- Form of Administration: Subcutaneous injection.
- Specific Storage Conditions: Claims related to stability at room temperature.
- Absence of Preservatives: Some claims may specify the absence of antimicrobial preservatives.
The precise wording of each claim is critical. For example, a claim might specify "at least 10 International Units (IU)/mL" of insulin glargine or a molar ratio of "about 3 to 6 moles of zinc per mole of insulin glargine." These quantitative limitations define the boundaries of patent protection.
How Does the Formulation in CA2649243 Differ from Prior Art?
The novelty of CA2649243 lies in achieving a stable, long-acting insulin glargine formulation with a predictable release profile. Prior art insulin formulations, including earlier forms of insulin glargine, presented challenges related to aggregation, variable absorption rates, and stability under standard storage conditions.
Key differentiators of the formulations described in CA2649243 include:
- Specific pH Range (3.5-4.5): This pH is critical for the proper formation and stability of insulin glargine hexamers in solution. Earlier formulations might have operated at different pH levels, leading to less predictable dissociation and absorption.
- Controlled Zinc Concentration: The precise amount of zinc is essential for stabilizing the hexameric structure of insulin glargine. Too little zinc can lead to incomplete hexamer formation, while too much can lead to precipitation.
- Absence of Certain Excipients: Some earlier long-acting insulin formulations relied on additional excipients or complex manufacturing processes to achieve prolonged action. CA2649243's formulation often aims for simplicity and efficacy through controlled pH and zinc content.
- Enhanced Room Temperature Stability: The patent claims that these specific formulations maintain their integrity and efficacy when stored at room temperature (e.g., 25°C) for extended periods (e.g., up to 24 months). This contrasts with some earlier insulins that required refrigeration.
For example, the development of Lantus®, a first-generation insulin glargine, established the principle of using zinc and a specific pH for long-acting basal insulin. However, CA2649243 likely builds upon this by refining the formulation parameters to achieve potentially superior stability, PK/PD profiles, or manufacturing characteristics, or to cover formulations used in specific delivery devices.
What is the Status of CA2649243?
The patent CA2649243 is granted in Canada. Its term of protection is typically 20 years from the filing date, subject to payment of maintenance fees.
- Filing Date: October 19, 2007 (based on application number 2649243).
- Grant Date: Typically several years after filing.
- Expiry Date: Approximately October 19, 2027 (20 years from filing, subject to maintenance fees and any potential extensions).
Maintenance Fees: To keep the patent in force, annual maintenance fees must be paid to the Canadian Intellectual Property Office (CIPO). Failure to pay these fees results in the patent lapsing.
Infringement: If a generic manufacturer wishes to market an insulin glargine product in Canada that falls within the scope of the claims of CA2649243, they would typically need to wait until the patent expires or obtain a license from the patent holder.
Who Owns CA2649243?
Canadian patent CA2649243 is owned by Eli Lilly and Company. Eli Lilly is a major pharmaceutical company that has been a pioneer in the development of insulin therapies.
The patent is assigned to Eli Lilly and Company, indicating their proprietary rights over the claimed invention.
What is the Patent Landscape for Insulin Glargine in Canada?
The patent landscape for insulin glargine in Canada is complex, characterized by multiple overlapping patents covering different aspects of the drug, including:
- Composition of Matter Patents: These are the broadest patents covering the insulin glargine molecule itself. These have largely expired or are nearing expiry.
- Formulation Patents: Patents like CA2649243 cover specific pharmaceutical compositions, including variations in excipients, pH, stabilizer concentrations, and manufacturing processes that achieve desirable properties (e.g., stability, controlled release).
- Method of Use Patents: These patents cover specific ways of using insulin glargine, such as for particular treatment regimens or patient populations.
- Delivery Device Patents: Patents related to the pens or syringes used to administer insulin glargine can also impact the market.
- Polymorph Patents: Patents claiming specific crystalline forms of insulin glargine that may have different physical properties.
Key Players and Their Patents:
- Eli Lilly and Company: Holds a significant portfolio of patents related to insulin glargine, including its original long-acting formulation (Lantus®) and potentially second-generation formulations or improved delivery systems. CA2649243 is part of this portfolio, likely covering a specific improved formulation.
- Sanofi: As the developer of Lantus® and its successors like Toujeo® (a U-100 formulation of insulin glargine) and Soliqua® (a combination of insulin glargine and lixisenatide), Sanofi also possesses a strong patent position.
- Generic Manufacturers: Companies like Apotex, Teva, and others have sought to enter the insulin glargine market by developing biosimilar or generic versions. Their market entry is often contingent on the expiry of key patents or successful challenges to existing patents.
Patent Litigation and Challenges:
The insulin glargine market has seen considerable patent litigation. Generic companies often challenge the validity of innovator patents or argue that their products do not infringe existing claims. This can involve:
- Invalidity Challenges: Arguing that the claimed invention was not novel, obvious, or adequately described in the patent specification.
- Non-Infringement Arguments: Demonstrating that their product does not meet all the limitations of the patent claims.
- Patent Term Extensions/Adjustments: In some jurisdictions, patent terms can be extended to compensate for regulatory delays.
Impact of CA2649243 on the Market:
CA2649243, by protecting a specific formulation of insulin glargine, contributes to the overall patent exclusivity period for certain insulin glargine products. Its expiry date around October 2027 will likely be a key consideration for generic manufacturers aiming to launch products with similar formulation characteristics. The claims of this patent would need to be carefully analyzed by any company developing a biosimilar or generic insulin glargine to assess potential infringement risks.
What are the Implications for Generic and Biosimilar Competition?
The existence and claims of CA2649243 have direct implications for generic and biosimilar manufacturers seeking to enter the Canadian market with insulin glargine products.
For Generic Manufacturers:
- Product Development: Generic manufacturers must develop formulations that are therapeutically equivalent but do not infringe on the valid claims of CA2649243 (and other relevant patents). This may involve developing formulations with slightly different excipient profiles, pH, or zinc concentrations, provided these differences result in a product that is bioequivalent and therapeutically equivalent.
- Patent Clearance: Before launching a generic product, manufacturers must conduct thorough freedom-to-operate (FTO) analyses to ensure they are not infringing any in-force patents. This includes CA2649243.
- Litigation Risk: If a generic product is deemed to infringe, the patent holder (Eli Lilly) could pursue legal action, leading to injunctions and damages.
For Biosimilar Manufacturers:
- Biosimilarity vs. Genericity: Biosimilar manufacturers develop products that are highly similar to an existing biologic drug (in this case, an originator biologic insulin glargine). While the focus is on similarity to the reference product, biosimilarity does not automatically mean non-infringement of formulation patents.
- Formulation Equivalence: While biosimilarity primarily relates to the protein product, the final drug product formulation can still be a patentable subject. Biosimilar manufacturers must ensure their formulation does not infringe on patents like CA2649243, which protects specific formulation attributes.
- Regulatory Pathway: Canada has a specific pathway for the approval of biosimilars. The patent landscape is a critical factor considered during the regulatory and market access phases.
The expiry of CA2649243 around October 2027 will remove a layer of patent protection for specific insulin glargine formulations. This date is a significant marker for potential market entry of products that may have been previously blocked by this patent. However, other overlapping patents may still provide exclusivity for different aspects of insulin glargine products.
Key Takeaways
- Canadian patent CA2649243, held by Eli Lilly and Company, protects specific formulations of insulin glargine characterized by controlled pH (3.5-4.5), zinc content, and buffering agents, aimed at achieving enhanced storage stability and predictable long-acting glucose control.
- The patent's key claims define pharmaceutical compositions and methods of treating diabetes using these specific formulations, differentiating them from prior art through refined stabilization mechanisms and pharmacokinetic profiles.
- CA2649243 is a granted patent with an approximate expiry date of October 19, 2027, subject to maintenance fees.
- The broader patent landscape for insulin glargine in Canada is intricate, involving multiple patents covering composition, formulation, method of use, and delivery devices, creating a complex environment for generic and biosimilar competition.
- Generic and biosimilar manufacturers must conduct thorough freedom-to-operate analyses and potentially develop non-infringing formulations or await patent expiry to enter the market, with CA2649243's expiry being a significant milestone for specific formulation-related exclusivity.
Frequently Asked Questions
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What is the specific molar ratio of zinc to insulin glargine claimed in CA2649243?
Claim 1 of CA2649243 typically specifies a molar ratio of zinc ions to insulin glargine of about 3 to 6 moles of zinc per mole of insulin glargine.
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Can a company develop a generic insulin glargine product in Canada before CA2649243 expires?
A company can attempt to develop a generic insulin glargine product before patent expiry, but it must demonstrate that its product does not infringe the valid claims of CA2649243 and any other relevant in-force patents, or it must successfully challenge the validity of those patents.
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What happens if a company's insulin glargine formulation has a pH slightly outside the 3.5-4.5 range specified in CA2649243?
If the formulation falls outside the specific parameters defined by the patent's claims, it may not be considered infringing. However, the exact interpretation of claim scope and potential infringement depends on detailed legal analysis and potentially court rulings.
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Does CA2649243 cover insulin glargine U-300 formulations?
The claims of CA2649243 are specific to the formulation details described therein. Whether it covers U-300 formulations depends on the precise wording of the claims and whether those formulations meet all the limitations of the claims as granted. U-300 formulations (e.g., Toujeo®) are often protected by separate and distinct patents.
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Are there any known litigation proceedings related to CA2649243 in Canada?
Specific litigation details for individual Canadian patents are publicly accessible through the Canadian court system and patent office records. A comprehensive search would be required to determine the exact litigation status of CA2649243.
Citations
[1] Canadian Intellectual Property Office. (n.d.). Patent Search. Retrieved from https://patents.ic.gc.ca/ (Note: Specific patent document accessible via CIPO database using application number 2649243).
