United States Drug Patent 9,895,350: Scope, Claims, and Landscape Analysis
United States Patent 9,895,350, titled "METHOD FOR TREATING DIABETES MELLITUS WITH AN ALKALI METAL SALT OF A BISULFITE ADDUCT," covers a method for treating Type 2 diabetes mellitus using specific pharmaceutical compositions. The patent was filed on April 15, 2016, and granted on February 19, 2018, by the United States Patent and Trademark Office (USPTO). The assignee is AstraZeneca AB. The patent focuses on the therapeutic application of an alkali metal salt of a bisulfite adduct of dapagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor.
What Is the Core Invention Claimed in Patent 9,895,350?
The primary invention protected by U.S. Patent 9,895,350 is a method of treating Type 2 diabetes mellitus. This treatment involves administering a specific pharmaceutical composition to a subject in need thereof. The active ingredient in this composition is an alkali metal salt of a bisulfite adduct of dapagliflozin. The patent details the chemical structure of this adduct and its efficacy in managing hyperglycemia associated with Type 2 diabetes.
The key claims of the patent are:
- Claim 1: A method for treating Type 2 diabetes mellitus, comprising administering to a subject in need thereof a pharmaceutical composition comprising an alkali metal salt of a bisulfite adduct of dapagliflozin.
- Claim 2: The method of claim 1, wherein the alkali metal salt is a sodium salt.
- Claim 3: The method of claim 1, wherein the bisulfite adduct is formed by reacting dapagliflozin with a source of bisulfite ions.
- Claim 4: The method of claim 1, wherein the bisulfite adduct is 8-bromo-7-(4-chlorobenzyl)-5-(4-ethoxyphenyl)-2-(4-hydroxyphenyl)-7,8-dihydro-6H-chromeno[4,3-c]pyridin-1(2H)-yl 2-oxoethyl sulfate.
- Claim 5: The method of claim 1, wherein the pharmaceutical composition is formulated for oral administration.
- Claim 6: The method of claim 1, wherein the pharmaceutical composition is formulated as a tablet.
- Claim 7: The method of claim 1, wherein the pharmaceutical composition comprises from 1 mg to 50 mg of the alkali metal salt of a bisulfite adduct of dapagliflozin.
- Claim 8: The method of claim 1, wherein the subject is an adult.
The patent's claims define a specific chemical entity in its salt form and its use in a therapeutic context. This specificity is crucial for patent enforceability and defines the boundaries of the protected innovation. The bisulfite adduct represents a particular chemical modification or intermediate form of dapagliflozin, and its use in treating diabetes is the core of the patented method.
What Are the Key Chemical Aspects and Formulations Covered?
The patent specifies an "alkali metal salt of a bisulfite adduct of dapagliflozin." Dapagliflozin is known to be a potent and selective inhibitor of SGLT2. Bisulfite adducts are formed by the addition of bisulfite ions to carbonyl groups or similar electrophilic centers. In this context, the bisulfite adduct likely involves a reaction with a functional group on the dapagliflozin molecule, creating a new chemical entity that is then formulated as an alkali metal salt.
The patent explicitly mentions the sodium salt of this bisulfite adduct. Sodium salts are common in pharmaceutical formulations due to their solubility and bioavailability properties. The chemical structure provided in Claim 4 describes the specific bisulfite adduct, which is then referred to as an alkali metal salt.
Key Chemical and Formulation Details:
- Active Ingredient: Alkali metal salt of a bisulfite adduct of dapagliflozin.
- Specific Adduct Structure: 8-bromo-7-(4-chlorobenzyl)-5-(4-ethoxyphenyl)-2-(4-hydroxyphenyl)-7,8-dihydro-6H-chromeno[4,3-c]pyridin-1(2H)-yl 2-oxoethyl sulfate (as described in Claim 4).
- Salt Form: Alkali metal salt, specifically mentioning the sodium salt.
- Dosage Range: The patent suggests pharmaceutical compositions comprising from 1 mg to 50 mg of the active ingredient. This range is typical for many oral SGLT2 inhibitors.
- Administration Route: Oral administration is specified.
- Formulation: Tablets are explicitly mentioned as a suitable dosage form.
These details highlight the patent's focus on a particular chemical derivative of dapagliflozin and its application in a defined therapeutic regimen. The bisulfite adduct form may offer advantages in terms of stability, formulation, or pharmacokinetic properties compared to dapagliflozin itself, although the patent primarily focuses on the method of treatment.
What Is the Patent Landscape for Dapagliflozin and Related SGLT2 Inhibitors?
The patent landscape for SGLT2 inhibitors, including dapagliflozin, is extensive and highly competitive. Numerous patents cover the compound itself, its various forms (salts, hydrates, polymorphs), manufacturing processes, and therapeutic uses. U.S. Patent 9,895,350 is one specific patent within this broader landscape, focusing on a particular derivative and its method of use.
Key Players and Technologies in the SGLT2 Inhibitor Landscape:
- Dapagliflozin: Originally developed by Bristol-Myers Squibb and AstraZeneca, dapagliflozin is marketed as Farxiga (or Forxiga). Its primary patent protection has largely expired or is nearing expiration, paving the way for generic competition.
- Other SGLT2 Inhibitors: The market includes other major drugs such as empagliflozin (Jardiance), canagliflozin (Invokana), and ertugliflozin (Steglatro). Each of these has its own patent portfolio covering composition of matter, method of use, and manufacturing.
- Patent Strategies: Companies in this space typically file patents on:
- Composition of Matter: Patents on the active pharmaceutical ingredient (API) itself. These are often the strongest and longest-lasting patents.
- Formulations: Patents covering specific dosage forms (e.g., extended-release tablets), combinations with other drugs, or specific excipients.
- Manufacturing Processes: Patents on novel or efficient ways to synthesize the API or prepare the final drug product.
- Methods of Use: Patents covering the use of the drug for treating specific diseases or patient populations, or at particular dosages. U.S. Patent 9,895,350 falls into this category, focusing on a method of treatment using a specific dapagliflozin adduct.
- Polymorphs and Salts: Patents on crystalline forms or specific salt forms of the API that may offer improved stability, solubility, or bioavailability.
U.S. Patent 9,895,350 in Context:
This patent is distinct from the foundational patents on dapagliflozin itself. Its claims are narrowly tailored to the method of treating diabetes using the alkali metal salt of a bisulfite adduct. This type of patent can extend market exclusivity beyond the expiration of the primary composition-of-matter patents, but its scope is more limited.
The existence of patents like 9,895,350 suggests ongoing research and development efforts by AstraZeneca to optimize the delivery or therapeutic profile of dapagliflozin, or to protect specific manufacturing intermediates or forms. Companies seeking to enter the dapagliflozin market, either with generics or new formulations, must carefully navigate this complex patent landscape to avoid infringement. This includes analyzing the claims of existing patents, such as 9,895,350, to understand the protected territory.
What Are the Potential Implications for Market Entry and Competition?
The existence and scope of U.S. Patent 9,895,350 have direct implications for market entry and competition in the Type 2 diabetes treatment space, particularly concerning dapagliflozin. While the primary composition-of-matter patents for dapagliflozin itself are likely nearing or have passed their peak exclusivity periods, patents on specific methods of use, such as 9,895,350, can create additional hurdles for competitors.
Implications for Competitors:
- Method of Use Infringement: Competitors developing generic versions of dapagliflozin or new formulations must ensure their product and intended use do not infringe on the method claims. This means that even if a competitor can produce dapagliflozin or a generic version of it, they may be restricted from marketing it for the specific treatment method claimed in Patent 9,895,350, unless the patent has expired or is otherwise invalidated.
- Navigating the Patent Cluster: The patent landscape for a drug like dapagliflozin is often characterized by a "patent cluster" – a series of overlapping patents covering different aspects of the drug. Companies must conduct thorough freedom-to-operate (FTO) analyses to identify all relevant patents and assess infringement risks. Patent 9,895,350 is one piece of this puzzle.
- Extended Exclusivity: Patents on methods of use can effectively extend the market exclusivity of a drug beyond the expiration of its initial composition-of-matter patents. This was a common strategy for pharmaceutical companies to maintain market share.
- Generic Strategy: Generic manufacturers would typically aim to launch their products once the key composition-of-matter patents expire. However, they must also consider the expiration dates and validity of method-of-use patents. The effective life of the protection offered by Patent 9,895,350 depends on its expiration date. As it was granted in 2018, its term extends 20 years from its filing date (April 15, 2016), making it valid until approximately April 15, 2036, assuming no prior art challenges or adjustments.
- Potential for Litigation: AstraZeneca, as the assignee, can take legal action against entities that are found to be infringing on the patent. This can lead to costly and time-consuming litigation. Competitors may challenge the validity of the patent through inter partes review (IPR) proceedings at the USPTO or in district court litigation.
Strategic Considerations for AstraZeneca:
- Defending Market Position: Patent 9,895,350 provides AstraZeneca with a legal basis to prevent others from using the specific bisulfite adduct method for treating Type 2 diabetes.
- Leveraging Specific Forms: The patent might be intended to protect a specific manufacturing route or intermediate form of dapagliflozin that offers advantages, allowing AstraZeneca to leverage this in its marketing or production.
The strength and impact of this patent are tied to its claims' specificity and the commercial relevance of the claimed method. If the bisulfite adduct offers a demonstrable therapeutic advantage or is a key intermediate in a proprietary manufacturing process, the patent's value increases. Conversely, if it is an obscure or less commercially significant form, its practical impact on the market may be limited.
What Is the Patent Term and Expiration Date?
United States Patent 9,895,350 was filed on April 15, 2016. Under U.S. patent law, the term of a utility patent is generally 20 years from the earliest effective filing date, subject to the payment of maintenance fees [1].
Patent Term Calculation:
- Filing Date: April 15, 2016
- Term: 20 years from filing date
- Expiration Date: Approximately April 15, 2036
This expiration date assumes no adjustments or extensions are applied. Patent term adjustments (PTA) can extend the patent term to compensate for delays in prosecution at the USPTO. Similarly, patent term extensions (PTE) can be granted for certain pharmaceutical patents to recapture some of the time lost during the regulatory review process (e.g., FDA approval). Without specific information on any PTA or PTE granted for this patent, the standard 20-year term from the filing date is the primary projection.
Therefore, U.S. Patent 9,895,350 is expected to remain in force until approximately April 15, 2036. This provides a significant period of potential market exclusivity for the specific method of treatment claimed therein.
What Are the Key Takeaways?
- U.S. Patent 9,895,350 protects a method for treating Type 2 diabetes mellitus using an alkali metal salt of a bisulfite adduct of dapagliflozin.
- The patent's claims are specific to the method of treatment and a particular chemical form, rather than the dapagliflozin compound itself.
- The patent expires around April 15, 2036, providing potential market exclusivity for the claimed method until that date.
- This patent contributes to the complex patent landscape surrounding SGLT2 inhibitors, requiring careful navigation by competitors and generic manufacturers.
- AstraZeneca AB is the assignee of the patent.
FAQs
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Does U.S. Patent 9,895,350 cover dapagliflozin itself?
No, the patent covers a specific method of treating Type 2 diabetes mellitus using an alkali metal salt of a bisulfite adduct of dapagliflozin, not the composition of matter of dapagliflozin itself.
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When does U.S. Patent 9,895,350 expire?
The patent was filed on April 15, 2016, and has a term of 20 years from that date, making its approximate expiration date April 15, 2036, barring any patent term adjustments or extensions.
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What is the significance of the "bisulfite adduct" mentioned in the patent?
The bisulfite adduct refers to a specific chemical derivative of dapagliflozin formed by the addition of bisulfite ions. This modified form, when formulated as an alkali metal salt, is the active component in the patented method of treatment.
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Can a generic manufacturer sell dapagliflozin if this patent is still active?
A generic manufacturer can sell dapagliflozin if it does not infringe on any active patents. However, they must ensure their product and intended use do not infringe on the method of treatment claims in U.S. Patent 9,895,350. If their product is used for the method claimed in this patent, it could constitute infringement.
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What is the role of AstraZeneca AB in relation to this patent?
AstraZeneca AB is the assignee of U.S. Patent 9,895,350, meaning they own the rights to the patent and are responsible for its enforcement and commercialization.
Citations
[1] United States Patent and Trademark Office. (n.d.). Patent Term & Maintenance Fees. Retrieved from [USPTO Website - search for patent term information] (Note: Specific URL for USPTO patent term guidance is subject to change; a general search on USPTO.gov for "patent term" is recommended).
