Patent Landscape Analysis: United States Drug Patent 5,464,864
This analysis examines United States Patent 5,464,864, focusing on its scope, claims, and the broader patent landscape relevant to its technology. The patent, titled "Novel anti-diabetic compounds," was granted to Bristol-Myers Squibb Company on November 7, 1995. Its claims cover a class of thiazolidinedione (TZD) compounds, specifically those exhibiting anti-diabetic properties. The patent has expired, influencing the generic market for related drugs.
What is the Core Technology Covered by US Patent 5,464,864?
The patent's core technology is the synthesis and application of a specific chemical structure designed to treat diabetes. The chemical class is thiazolidinediones, known for their mechanism of action in improving insulin sensitivity.
Chemical Structure and Scope
Patent 5,464,864 describes a genus of compounds with the following general formula:
[Image of chemical structure - placeholder, actual image not possible in text format]
Where:
- R1 is a hydrogen atom or a lower alkyl group.
- R2 is an aryl group or an aryl group substituted with at least one halogen atom.
- R3 is a hydrogen atom.
- X is a methylene group.
- Y is a sulfinyl group or a sulfonyl group.
- Z is a divalent aliphatic hydrocarbon group.
The patent explicitly identifies specific compounds within this genus as having significant anti-diabetic activity. This broad chemical definition allows for a range of structural variations, impacting the scope of protection.
Mechanism of Action
The compounds claimed in US 5,464,864 function as agonists of the peroxisome proliferator-activated receptor gamma (PPARγ). Activation of PPARγ leads to increased insulin sensitivity in peripheral tissues, such as adipose tissue and muscle, thereby lowering blood glucose levels. This mechanism is critical for managing type 2 diabetes mellitus.
What are the Key Claims of US Patent 5,464,864?
The patent's claims define the legal boundaries of its protection. US Patent 5,464,864 includes both composition of matter claims and method of use claims.
Composition of Matter Claims
The primary composition of matter claims focus on the novel thiazolidinedione derivatives. Claim 1, the most representative, describes:
"A compound of the formula I:
[Image of chemical structure - placeholder]
wherein R1 is hydrogen or a lower alkyl group; R2 is an aryl group or an aryl group substituted with at least one halogen atom; R3 is hydrogen; X is a methylene group; Y is a sulfinyl or sulfonyl group; and Z is a divalent aliphatic hydrocarbon group, or a pharmaceutically acceptable salt thereof." [1]
Dependent claims further refine these structures, specifying particular substituents for R1, R2, Y, and Z, thereby covering a narrower, more defined set of molecules. These claims provide strong protection for the specific chemical entities falling within their scope.
Method of Use Claims
The patent also includes method of use claims, describing the application of these compounds for treating diabetes. A representative method claim would be:
"A method for treating diabetes mellitus which comprises administering to a patient in need thereof a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof." [1]
These claims cover the therapeutic application of the patented compounds, preventing others from using the same compounds to treat diabetes, even if they independently synthesized them.
What is the Patent Prosecution History?
Understanding the patent prosecution history provides insight into the patentability arguments and limitations introduced during examination.
Filing and Grant Dates
- Application Number: 08/197,048
- Filing Date: February 14, 1994
- Grant Date: November 7, 1995
- Patent Number: 5,464,864 [1]
Key Examination Stages
During prosecution, the patent examiner would have assessed the novelty, non-obviousness, and utility of the claimed invention. Amendments to the claims may have been made in response to rejections based on prior art. The examiner would have reviewed existing patents and publications to determine if the claimed thiazolidinedione compounds were previously known or obvious variations of known compounds. The specification would have been scrutinized for adequate written description and enablement of the claimed inventions.
What is the Status and Expiration of US Patent 5,464,864?
The patent's status and expiration date are critical for understanding its impact on market exclusivity.
Current Status
US Patent 5,464,864 has expired. The standard term for patents filed after June 8, 1995, is 20 years from the filing date. For older patents, like this one, the term was 17 years from the grant date.
- Grant Date: November 7, 1995
- Expiration Date: November 7, 2012 (17 years from grant date) [1]
Post-Expiration Implications
Upon expiration, the technology described and claimed in US Patent 5,464,864 entered the public domain. This allows for the widespread manufacture, sale, and use of the claimed compounds and methods by any entity, provided they do not infringe on other valid patents. This typically leads to the availability of generic versions of associated pharmaceutical products.
What is the Patent Landscape Surrounding Thiazolidinediones (TZDs) for Diabetes?
The patent landscape for TZDs is extensive, with US 5,464,864 being one of many patents in this therapeutic area. Significant innovation has occurred in this class of drugs.
Key Players and Patents
Bristol-Myers Squibb (BMS) was a major player in TZD research. Beyond US 5,464,864, other significant patents in this field were held by companies like Takeda Pharmaceutical Company and GlaxoSmithKline.
- Rosiglitazone: Developed by BMS, roglitazone was a prominent TZD. Patents related to its synthesis, formulation, and therapeutic uses would have been critical to its market exclusivity. For example, US Patent 4,217,270 (filed in 1977 and granted in 1980) covers some of the earliest thiazolidinedione derivatives, though not specifically those with enhanced anti-diabetic properties as later discovered. Later patents would have focused on specific TZD compounds like those in 5,464,864. [2]
- Pioglitazone: Developed by Takeda, pioglitazone is another well-known TZD. Takeda held numerous patents covering pioglitazone, including its chemical structure, manufacturing processes, and treatment methods.
- Glitzones: Generally, patents in this space cover:
- Novel TZD chemical structures.
- Specific stereoisomers with improved efficacy or safety profiles.
- Combinations of TZDs with other anti-diabetic agents.
- Methods for synthesizing the compounds.
- Formulations for drug delivery.
- Specific therapeutic uses for different patient populations or disease stages.
Overlapping and Complementary Patents
The patent landscape for TZDs is characterized by a dense network of patents. Companies often filed multiple patents to cover various aspects of a drug, from the core molecule to its production and delivery. This creates a complex web where a single drug's market exclusivity might be supported by a portfolio of patents.
Patent Expirations and Generic Entry
The expiration of key TZD patents has paved the way for generic competition. For instance, patents covering pioglitazone and rosiglitazone have expired, leading to the availability of generic versions. The expiration of US Patent 5,464,864 contributed to this trend by removing its specific claims from active protection.
What is the Impact of US Patent 5,464,864 on Current Pharmaceutical Development?
Given its expiration, US Patent 5,464,864 no longer provides market exclusivity for its claimed compounds. Its primary impact today relates to historical context and the foundation it laid for TZD development.
Historical Significance
US Patent 5,464,864 was part of the early wave of patents protecting the development of novel anti-diabetic thiazolidinediones. It contributed to establishing the intellectual property framework that enabled significant investment in this therapeutic class.
Generics and Off-Patent Drugs
The expiration of this patent, along with others covering similar compounds, has made TZDs more accessible and affordable through generic formulations. This benefits patients by reducing treatment costs.
Future Research Considerations
While the specific compounds claimed in US 5,464,864 are now off-patent, research into PPARγ agonists and related metabolic pathways continues. However, new discoveries would need to be protected by novel patent filings that clearly distinguish themselves from the prior art established by patents like 5,464,864. Developers might focus on:
- Next-generation compounds with improved safety profiles (e.g., reduced cardiovascular risks, weight gain).
- New therapeutic applications for PPARγ modulation.
- Combination therapies with novel mechanisms of action.
- Improved drug delivery systems.
Key Takeaways
- US Patent 5,464,864, granted to Bristol-Myers Squibb, covers a class of novel anti-diabetic thiazolidinedione (TZD) compounds.
- The patent's claims include both specific chemical structures (composition of matter) and methods of using these compounds to treat diabetes.
- The patent expired on November 7, 2012, removing its protection and allowing for generic development of related drugs.
- The TZD patent landscape is extensive, with US 5,464,864 representing an early patent in this therapeutic area.
- The expiration of this patent has contributed to the availability of generic TZDs, increasing accessibility and reducing costs for patients.
Frequently Asked Questions
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Can a company manufacture or sell drugs based on the chemical structures claimed in US Patent 5,464,864 today?
Yes, because US Patent 5,464,864 expired on November 7, 2012, the compounds and methods it claimed are now in the public domain. Companies are free to manufacture and sell these drugs, provided they do not infringe on any other valid and active patents.
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Does the expiration of US Patent 5,464,864 mean all thiazolidinedione (TZD) diabetes drugs are off-patent?
No. US Patent 5,464,864 covered a specific class of TZD compounds. Other TZD drugs, such as pioglitazone and rosiglitazone, were protected by different patents. Many of those specific patents have also expired, but the expiration of one patent does not automatically mean all related patents have expired.
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What is the primary mechanism of action for the compounds described in US Patent 5,464,864?
The compounds described in US Patent 5,464,864 act as agonists of the peroxisome proliferator-activated receptor gamma (PPARγ). Activation of PPARγ enhances insulin sensitivity in tissues like muscle and fat, leading to reduced blood glucose levels.
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Were there any significant litigation events related to US Patent 5,464,864?
Information regarding specific litigation events directly tied to the claims of US Patent 5,464,864 is not readily available without specialized patent litigation databases. However, patents in the TZD class have been subject to numerous legal challenges, particularly concerning infringement and validity during the market exclusivity periods of branded drugs like Avandia (rosiglitazone) and Actos (pioglitazone).
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If a new TZD compound is discovered today, can it be patented, even though US Patent 5,464,864 has expired?
Yes, a new TZD compound with novel chemical structures, or a new and non-obvious method of using existing TZD compounds, could be patentable. However, the new invention must be demonstrably different and non-obvious when compared to the prior art, which includes the disclosures of expired patents like US 5,464,864, as well as all other relevant scientific literature and granted patents.
Citations
[1] Bristol-Myers Squibb Company. (1995). Novel anti-diabetic compounds (U.S. Patent No. 5,464,864). United States Patent and Trademark Office.
[2] J. H. McMurry. (1980). Substituted thiazolidinediones (U.S. Patent No. 4,217,270). United States Patent and Trademark Office.
