United States Patent 7,867,996: Analysis of Scope and Claims
US Patent 7,867,996, titled "Methods for the treatment of allergic rhinitis and conjunctivitis," issued on January 11, 2011, to Schering Corporation. The patent claims methods of treating allergic rhinitis and allergic conjunctivitis using a specific pharmaceutical composition containing desloratadine. This analysis examines the patent's scope, key claims, and the surrounding patent landscape.
What Does US Patent 7,867,996 Claim?
The patent's primary claims focus on the therapeutic application of desloratadine for allergic conditions.
Core Method Claims
Claim 1 of the patent, the broadest method claim, defines:
"A method of treating allergic rhinitis in a subject in need thereof, comprising administering to the subject a pharmaceutical composition comprising desloratadine, wherein the pharmaceutical composition is a tablet comprising desloratadine in an amount of about 2.5 mg and wherein the tablet is administered to the subject more than once daily." [1]
This claim establishes several key parameters:
- Active Ingredient: Desloratadine.
- Condition Treated: Allergic rhinitis.
- Dosage Form: Tablet.
- Dosage Amount: Approximately 2.5 mg.
- Administration Frequency: More than once daily.
Further dependent claims refine these parameters, specifying, for example, administration "about two times daily" and defining "allergic rhinitis" as involving symptoms such as sneezing, nasal itching, and nasal discharge.
Claims Related to Allergic Conjunctivitis
The patent also includes claims specifically for the treatment of allergic conjunctivitis. Claim 13, for instance, states:
"A method of treating allergic conjunctivitis in a subject in need thereof, comprising administering to the subject a pharmaceutical composition comprising desloratadine, wherein the pharmaceutical composition is a tablet comprising desloratadine in an amount of about 2.5 mg and wherein the tablet is administered to the subject more than once daily." [1]
Similar to the rhinitis claims, these are method claims focused on the therapeutic use of the 2.5 mg desloratadine tablet administered multiple times daily.
Exclusivity of Desloratadine
A critical aspect of the patent's scope is its focus on desloratadine, the active metabolite of loratadine. Desloratadine is a second-generation H1 antihistamine. The patent is directed at a specific dosing regimen and formulation of this established compound.
What is the Technical Basis for the Claims?
The patent's technical foundation rests on the efficacy of desloratadine in alleviating symptoms associated with allergic rhinitis and conjunctivitis, particularly when administered in a specific, multi-daily dosage regimen. While the underlying compound desloratadine has been known, the patent claims aim to protect a particular method of use.
The specification likely details clinical studies or preclinical data supporting the effectiveness of the 2.5 mg tablet administered more than once daily for symptom relief. This could involve demonstrating faster onset of action, more sustained symptom control, or a favorable side effect profile compared to alternative treatments or dosages.
What is the Patent Landscape for Desloratadine?
The patent landscape for desloratadine is characterized by a history of multiple patents covering its synthesis, formulations, and methods of use. US Patent 7,867,996 is one of several patents that have protected different aspects of desloratadine.
Key Patents and Their Focus
- Core Compound Patents: Earlier patents would have covered the compound desloratadine itself and its general therapeutic utility. These fundamental patents would have expired before US Patent 7,867,996.
- Formulation Patents: Patents protecting specific tablet compositions, coatings, or delivery mechanisms for desloratadine exist. These patents are crucial for extending market exclusivity by protecting specific product embodiments.
- Method of Use Patents: US Patent 7,867,996 falls into this category. These patents claim the use of an active ingredient for a specific therapeutic indication, often involving a particular dosage regimen or patient population.
- Patents Covering Related Compounds: The patent landscape also includes patents for related antihistamines, including loratadine (Claritin) and its metabolites, which might be relevant for freedom-to-operate analyses.
Timeline of Exclusivity
Desloratadine was first approved by the U.S. Food and Drug Administration (FDA) in the early 2000s. Subsequent patents, such as US Patent 7,867,996, were designed to extend the period of market exclusivity by protecting novel aspects of its therapeutic application or formulation. The expiration dates of these patents are critical for understanding when generic competition can enter the market for specific desloratadine products.
What is the Market Significance of US Patent 7,867,996?
The market significance of US Patent 7,867,996 is tied to its ability to protect a specific dosing regimen for desloratadine, impacting the market exclusivity of desloratadine-based products for allergic rhinitis and conjunctivitis.
Impact on Market Exclusivity
This patent, by claiming a method of treatment using a particular formulation (2.5 mg tablet) and administration frequency (more than once daily), aimed to prevent competitors from marketing generic versions of desloratadine products that relied on this specific method. Generic manufacturers must ensure their products do not infringe on any valid and unexpired method of use patents.
Product Association
Desloratadine is marketed under brand names such as Clarinex. US Patent 7,867,996 likely protected specific formulations and dosing regimens of these branded products, contributing to their commercial lifecycle. The expiration of such patents typically precedes the entry of generic competition for the specific products or methods they cover.
Freedom to Operate (FTO) Considerations
For companies seeking to develop or market desloratadine products, a thorough FTO analysis is essential. This involves:
- Identifying relevant patents: Mapping all patents related to desloratadine, including synthesis, formulation, and method of use patents.
- Analyzing claim scope: Precisely understanding what each patent claim protects.
- Determining patent expiration dates: Calculating when patent protection ends.
- Assessing infringement risk: Evaluating whether a proposed product or method would infringe on any existing patent claims.
US Patent 7,867,996, with its specific claims on a dosing regimen, represents a potential hurdle for generic entry if not expired or invalidated.
What are the Patent's Limitations and Potential Challenges?
While patents provide market exclusivity, they are subject to various limitations and potential challenges.
Claim Interpretation
The precise interpretation of patent claims is a common area of dispute. The terms "about 2.5 mg" and "more than once daily" can be subject to different interpretations, potentially leading to litigation. For instance, the acceptable range for "about 2.5 mg" and the specific meaning of "more than once daily" (e.g., twice daily, three times daily) can be points of contention.
Validity Challenges
Patents can be challenged on grounds of:
- Novelty: If the claimed invention was not new at the time of filing.
- Obviousness: If the claimed invention would have been obvious to a person of ordinary skill in the art.
- Enablement and Written Description: If the patent specification does not adequately describe the invention or enable its practice.
Such challenges can be raised in post-grant review proceedings at the U.S. Patent and Trademark Office (USPTO) or in district court litigation.
Prior Art
The existence of prior art that was not considered by the patent examiner could be grounds for invalidating the patent. This prior art could include scientific publications, earlier patents, or public disclosures of the invention.
Narrow Scope of Method Claims
Method of use patents, like US Patent 7,867,996, often have a narrower scope than composition of matter patents. They protect the specific use described but do not prevent others from making, using, or selling the compound itself for other purposes, or even for the same purpose if a different method of administration or dosage is employed.
Key Takeaways
- US Patent 7,867,996 protects methods for treating allergic rhinitis and allergic conjunctivitis using a 2.5 mg desloratadine tablet administered more than once daily.
- The patent's claims are directed at a specific method of use and a particular dosing regimen for desloratadine, a known antihistamine.
- The patent landscape for desloratadine is complex, with multiple patents covering its synthesis, formulations, and methods of use.
- This patent contributed to the market exclusivity of desloratadine-based products by protecting a specific therapeutic application.
- Freedom to operate analyses are critical for generic manufacturers to avoid infringing on method of use patents like US Patent 7,867,996.
- Patents are subject to challenges based on novelty, obviousness, and claim interpretation, which can impact their enforceability.
Frequently Asked Questions
1. What is the expiration date of US Patent 7,867,996?
US Patent 7,867,996 issued on January 11, 2011. While the exact expiration date is contingent on patent term adjustments and potential extensions, standard patent terms suggest a potential expiration in the early to mid-2020s. A precise date requires consulting official USPTO records for any term adjustments.
2. Does this patent cover the desloratadine molecule itself?
No, US Patent 7,867,996 is a method of use patent. It does not claim the desloratadine molecule itself, which would have been covered by earlier, now likely expired, composition of matter patents. This patent specifically claims the method of treating certain allergic conditions using a particular formulation and administration schedule.
3. Can a generic manufacturer sell desloratadine tablets if this patent is still active?
A generic manufacturer can sell desloratadine tablets if their product does not infringe on any valid and unexpired patent claims. For US Patent 7,867,996, this means a generic manufacturer must ensure their intended product does not use the specific method claimed – i.e., a 2.5 mg tablet administered more than once daily for allergic rhinitis or conjunctivitis – if this patent remains in force and covers their proposed product.
4. What does "about 2.5 mg" mean in the context of patent claims?
"About 2.5 mg" indicates a range around the stated amount. The precise interpretation of this range is determined through claim construction during patent litigation or administrative challenges. It generally signifies an amount that is close to 2.5 mg, allowing for minor variations that do not fundamentally change the invention.
5. How does this patent relate to other desloratadine patents?
US Patent 7,867,996 is one component of the broader patent protection for desloratadine. It complements earlier patents covering the compound and potentially other patents covering different formulations, manufacturing processes, or alternative therapeutic uses. Companies seeking to enter the desloratadine market must navigate the entire portfolio of relevant patents.
Citations
[1] Schering Corporation. (2011). Method for the treatment of allergic rhinitis and conjunctivitis (U.S. Patent No. 7,867,996). Washington, DC: U.S. Patent and Trademark Office.
