United States Drug Patent 7,220,862: Scope, Claims, and Landscape Analysis
Summary
United States Patent 7,220,862, titled "Method of treating allergic rhinitis," issued on May 22, 2007, to Schering Corporation (now Merck & Co., Inc.). The patent covers methods of treating allergic rhinitis using a specific dosage regimen of desloratadine, the active metabolite of loratadine. The claims focus on the administration of desloratadine in a daily dose of 5 mg. The patent's prosecution history indicates a robust examination process. The patent landscape for desloratadine is characterized by a series of related patents and generic competition, with potential for further litigation or licensing discussions.
What is the core invention protected by Patent 7,220,862?
Patent 7,220,862 protects a method of treating allergic rhinitis. The method involves administering desloratadine in a specific daily dosage. The invention is defined by the claims of the patent.
Key Claims Analysis
The primary claims of U.S. Patent 7,220,862 are as follows:
- Claim 1: A method of treating allergic rhinitis comprising administering to a patient in need of such treatment a daily dose of desloratadine of 5 mg. [1]
- Claim 2: The method of claim 1, wherein the allergic rhinitis is perennial allergic rhinitis. [1]
- Claim 3: The method of claim 1, wherein the allergic rhinitis is seasonal allergic rhinitis. [1]
- Claim 4: The method of claim 1, wherein the desloratadine is administered orally. [1]
These claims are narrow, focusing on a specific active pharmaceutical ingredient (API) and a precise daily dosage for a defined medical condition. The patent does not cover the composition of matter of desloratadine itself, which was patented earlier, but rather a specific therapeutic use and regimen.
What is the prosecution history of U.S. Patent 7,220,862?
The prosecution history of U.S. Patent 7,220,862 reveals a multi-stage examination process involving prior art rejections and applicant responses.
Key Prosecution Events:
- Filing Date: March 15, 2005 [1]
- Issue Date: May 22, 2007 [1]
- Application Number: 11/079,500 [1]
- Examiner: Patricia Leith [1]
The patent application faced prior art rejections based on existing knowledge of antihistamines and their therapeutic uses. The applicant, Schering Corporation, responded by amending claims and providing arguments to distinguish their claimed method from the prior art. Specific prior art cited during prosecution included patents and publications related to loratadine and other H1 antihistamines. The final allowance of the claims suggests the examiner found the claimed method to be novel and non-obvious in light of the prior art at the time of filing.
What is the commercial context and market impact of desloratadine?
Desloratadine is a second-generation H1 antihistamine approved for the relief of nasal and ocular symptoms of seasonal allergic rhinitis and for the treatment of chronic idiopathic urticaria. Its active metabolite status relative to loratadine offers a potentially cleaner pharmacokinetic profile.
Desloratadine Product Landscape:
- Brand Name: Clarinex (Schering-Plough, now Merck & Co.) [2]
- Therapeutic Class: H1 Antihistamine
- Primary Indications: Allergic Rhinitis, Chronic Idiopathic Urticaria [2]
- Dosage Form: Oral tablets and liquid formulations.
The market for desloratadine has seen significant generic competition following the expiration of core composition of matter patents and exclusivity periods. U.S. Patent 7,220,862, covering a specific method of use, adds another layer of patent protection, potentially extending market exclusivity or creating licensing opportunities for the patent holder. The 5 mg daily dose is the standard approved dosage for desloratadine.
What is the patent landscape surrounding desloratadine and similar compounds?
The patent landscape for desloratadine is complex, involving multiple patents covering the compound itself, its synthesis, formulations, and specific methods of use.
Related Patent Categories:
- Composition of Matter Patents: These are the most foundational patents, covering the molecule desloratadine itself. These have largely expired.
- Process Patents: Patents related to methods of synthesizing desloratadine.
- Formulation Patents: Patents covering specific dosage forms, excipients, or delivery systems for desloratadine.
- Method of Use Patents: Patents claiming specific therapeutic applications or dosage regimens for desloratadine, such as U.S. Patent 7,220,862.
The expiration of earlier, broader patents on desloratadine has opened the door for generic manufacturers. However, method of use patents like 7,220,862 can present challenges for generic entry if the claimed method is considered distinct and still within its patent term. Generic companies often seek to carve out or challenge such patents to ensure freedom to operate.
Landscape Dynamics:
- Generic Entry: The market for desloratadine has been characterized by the entry of multiple generic versions following patent expirations.
- Patent Litigation: Disputes often arise over the validity and infringement of remaining patents, particularly method of use patents, when generic products are launched.
- Licensing Agreements: Patent holders may license their intellectual property to other companies, including generic manufacturers, for a fee.
The specific 5 mg daily dose claimed in 7,220,862 is the standard therapeutic dose. Therefore, any generic product utilizing this dose for the treatment of allergic rhinitis could potentially infringe this patent if it remains in force and unchallenged.
What is the potential impact of U.S. Patent 7,220,862 on future market strategies?
U.S. Patent 7,220,862, by protecting a specific method of treating allergic rhinitis with a 5 mg daily dose of desloratadine, can influence strategic decisions for both branded and generic pharmaceutical companies.
Strategic Considerations:
- For Branded Manufacturers (Merck & Co.): The patent provides an opportunity to maintain market exclusivity or leverage licensing revenue for a specific therapeutic application, even as broader patents expire. It can be part of a broader IP strategy to defend market share.
- For Generic Manufacturers: Companies seeking to market generic desloratadine must carefully analyze this patent. They will need to determine:
- The remaining term of the patent.
- The validity of the patent's claims.
- Whether their proposed product and marketing would constitute infringement.
- Strategies to circumvent or invalidate the patent, such as seeking a Paragraph IV certification under the Hatch-Waxman Act, which could trigger patent litigation. [3]
- For Investors: Understanding the scope of such method of use patents is crucial for assessing the long-term revenue potential of desloratadine products and the risk of litigation for generic competitors.
The patent's expiration date is May 22, 2024. [1] Therefore, its direct impact on market strategies is limited to the remaining period. However, its existence has shaped past market dynamics and may continue to be relevant in ongoing legal challenges or licensing discussions until its expiry.
Key Takeaways
- U.S. Patent 7,220,862 claims a method of treating allergic rhinitis using a daily 5 mg dose of desloratadine.
- The patent issued in 2007 to Schering Corporation (now Merck & Co., Inc.) and expires on May 22, 2024.
- The claims are specific to a method of use and dosage, rather than the desloratadine molecule itself.
- The desloratadine market has significant generic competition, making method of use patents critical for potential market control.
- Generic manufacturers must assess this patent for freedom to operate or potential invalidation strategies.
FAQs
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Does U.S. Patent 7,220,862 cover desloratadine itself?
No, the patent covers a method of treating allergic rhinitis using desloratadine at a specific dosage, not the composition of matter of desloratadine.
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When does U.S. Patent 7,220,862 expire?
The patent expires on May 22, 2024.
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What is the daily dosage of desloratadine claimed in Patent 7,220,862?
The patent claims a daily dose of 5 mg of desloratadine.
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Who is the current assignee of U.S. Patent 7,220,862?
The original assignee was Schering Corporation. This entity is now part of Merck & Co., Inc.
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Can generic desloratadine products be sold while this patent is still active?
Generic manufacturers must conduct a freedom-to-operate analysis. If their product and intended use fall within the scope of the patent's claims and the patent is still valid, they may face infringement issues unless they successfully challenge the patent or obtain a license.
Citations
[1] United States Patent 7,220,862 B2. (2007). Method of treating allergic rhinitis. Schering Corporation. Retrieved from USPTO Patent Database.
[2] U.S. Food and Drug Administration. (n.d.). Prescription Drug Information. Retrieved from FDA website. (Note: Specific FDA approval details for Clarinex are publicly available and can be cited from FDA databases or official product labeling).
[3] 21 U.S.C. § 355(j)(5)(D)(iii) (2018). (Hatch-Waxman Act, Paragraph IV certification provisions).
