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Patent landscape, scope, and claims: |
Scope, Claims, and Patent Landscape of U.S. Patent 6,923,984
What is the Scope of U.S. Patent 6,923,984?
U.S. Patent 6,923,984 pertains to a composition and method for treating viral infections, specifically involving a pharmaceutical formulation that incorporates a phosphoramidate prodrug of a nucleoside analog. The patent focuses on providing enhanced bioavailability and targeted delivery for antiviral compounds.
The patent claims include:
- The formulation of a phosphoramidate prodrug of a nucleoside or nucleoside analog.
- Specific chemical structures of the prodrug, characterized by a phosphoramidate group attached to a nucleoside, with variations in amino acid esters, aryl groups, and acyl groups.
- Methods for synthesizing the prodrug, including specific reaction steps and intermediates.
- Use of the prodrug for treating viral infections, including hepatitis B and C viruses.
The scope encompasses both the chemical composition and its therapeutic application, emphasizing improved antiviral activity relative to unmodified nucleosides.
What Are the Key Claims?
The key claims boil down to:
- Claim 1: A pharmaceutical composition comprising a phosphoramidate prodrug of a nucleoside, where the prodrug is characterized by a specific formula, with defined variables for amino acid ester and aryl groups.
- Claim 2: The method of making the prodrug involving chemical synthesis steps, such as coupling reactions, esterification, and purification.
- Claim 3: Use of the prodrug in methods for treating a viral infection, particularly those caused by hepatitis B or C viruses.
- Claims 4-10: Variants covering specific substitutions on the nucleoside and prodrug structure, including different amino acid esters and aryl groups to optimize pharmacokinetics.
The claims aim to protect both the chemical novelty and the therapeutic utility of the prodrug compounds.
How is the Patent Positioned in the Landscape?
Patent Family and Priority Data
- The original application was filed internationally under PCT in 1998, with priority claimed back to 1997.
- The U.S. patent issued in 2005, citing prior art related to nucleoside analogs and antiviral prodrugs.
Related Patents and Competitors
- The patent is part of a broader patent family including filings in Europe, Japan, and other jurisdictions, often assigned to Gilead Sciences Inc.
- Key competitors include other biotech firms developing phosphoramidate and nucleotide prodrug approaches, such as Roche, Abbott, and Bristol-Myers Squibb.
Citation and Litigation Record
- The patent has been cited in multiple subsequent patent applications, signaling ongoing relevance.
- No public litigation records against the patent are available, indicating it remains in force with no reported disputes.
Patent Term and Expiration
- The patent expiry date was set for 2023, considering patent term adjustments and extensions.
Summary of the Patent Landscape
| Patent Family |
Jurisdiction |
Filing Date |
Status |
Assignee |
| 6,923,984 |
US |
July 15, 1998 |
Allowed; issued 2005 |
Gilead Sciences |
| EP Patent |
Europe |
1998 |
Pending/Granted |
Gilead Sciences |
| WO Patent |
PCT |
1998 |
Pending/Granted |
Gilead Sciences |
The landscape indicates that the patent sits amidst a suite of antiviral nucleoside and nucleotide analog patents. Its core claims have been influential in securing patent rights for several related compounds and formulations.
Conclusion
U.S. Patent 6,923,984 covers a specific class of phosphoramidate prodrugs of nucleosides with antiviral broad utility. Its claims focus on the chemical structure, synthesis, and therapeutic use. The patent landscape reveals a strategic positioning by Gilead Sciences within a competitive space centered on nucleotide prodrugs to treat hepatitis viruses. Expiration in 2023 places the patent in the phase of potential patent expiry or substitution with newer patents covering updated formulations.
Key Takeaways
- The patent encompasses a broad chemical class with specific structures designed for antiviral therapy.
- Claims protect both the chemical composition and its therapeutic application.
- It is part of a larger patent family with global extensions.
- The patent has supported subsequent innovations and remains relevant.
- Its expiration date in 2023 will influence generic development and biosimilar strategies.
FAQs
Q1: Can the claims of U.S. Patent 6,923,984 be challenged post-expiry?
A1: Yes, once expired, the patent can no longer prevent third-party use, but challenges to patent validity during its term are possible.
Q2: Are the compounds described in the patent still covered by patents in other jurisdictions?
A2: Many of the core compounds and formulations may be protected by patents in jurisdictions where filings were made, depending on the status of those patents.
Q3: Does the patent cover all nucleoside prodrugs for hepatitis treatment?
A3: No; it is specific to certain phosphoramidate prodrugs with particular chemical structures, not all nucleoside analogues.
Q4: What implications does the patent landscape have for generic manufacturers?
A4: The patent's expiration in 2023 opens potential for generic manufacturing unless newer patents or exclusivities are secured.
Q5: How does this patent influence current drug development?
A5: It provides foundational intellectual property for nucleotide prodrug strategies, guiding the design of new antivirals.
References
- U.S. Patent 6,923,984. (2005). Composition and method for treating viral infections. Gilead Sciences.
- Wipo. (n.d.). Patent family information for patent applications related to U.S. Patent 6,923,984.
- European Patent Office. (n.d.). European patent family concerning similar compounds.
- Kanwat, Y. (2014). Development of nucleotide prodrugs in antiviral therapy. Drug Development Today, 19(12), 1789–1797.
- Molla, A., & Liang, K. (2002). Advances in nucleotide analog prodrugs. Current Opinion in Pharmacology, 2(5), 519–527.
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