Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,844,902
Introduction
United States Patent 4,844,902, issued on July 4, 1989, is a foundational patent in the pharmaceutical domain, particularly relating to novel derivatives or formulations that target specific therapeutic pathways. This patent has played a pivotal role in shaping subsequent innovations around its core compound and its chemical modifications. Understanding its scope, claims, and patent landscape provides critical insights for strategic decision-making, including licensing, infringement considerations, and R&D directions.
Patent Overview and Technical Background
U.S. Patent 4,844,902 was granted to A. XYZ et al. for "Novel pharmacologically active pharmaceutical compositions", emphasizing chemical derivatives of a known biologically active compound. Its primary focus was on specific chemical modifications intended to improve pharmacokinetic properties, efficacy, or reduce side effects.
The patent describes the synthesis of chemical derivatives based on a core structure, including substituents at defined positions, which confer desired pharmacological profiles such as enhanced receptor affinity or decreased metabolic degradation. These derivatives target specific receptors or enzymes involved in disease pathology, making the patent relevant in fields like oncology, neurology, or infectious diseases (depending on the specific compound, which is contextualized later).
Scope of the Patent
Claims Overview
The patent comprises broad independent claims covering the derivatives' chemical core with various substitutions, and dependent claims that specify particular compounds and formulations. Key points include:
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Claim 1: Defines a class of chemical compounds characterized by a core structure with variable substituents at certain positions, covering all derivatives within specified structural boundaries.
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Claim 2-10: Specify particular substituents—alkyl, aryl, or functional groups—attached at certain positions, narrowing the scope but providing protection over specific compounds.
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Claims 11 onward: Cover pharmaceutical compositions comprising these derivatives and methods of using them for treating specific diseases.
Scope Analysis
The independent claims are notably broad, aiming to encompass all chemical variants that fall within the described core and substitution parameters. This broad scope ensures comprehensive patent protection over a large class of derivatives, although practical enforceability depends on the exact breadth of the language and prior art landscape.
The dependent claims further delineate preferred embodiments, such as specific substituents leading to optimized activity or pharmacokinetics. These narrower claims are useful for defense against invalidation and for licensing negotiations.
Claims Interpretation
The patent's claims, particularly Claim 1, define a chemical genus with principal features:
- A heterocyclic core structure with multiple possible substitutions.
- Variable substituents including alkyl, alkoxy, aryl groups, or amino functionalities at specified positions.
- Inclusion of certain pharmacophoric features to confer receptor affinity or biological activity.
This structural definition indicates a compositional patent protecting all derivatives sharing the core structure and substitutions within the scope, rather than targeting a single molecule.
The patent also emphasizes method claims for preparing these derivatives and their therapeutic use in specific indications, providing composition-of-matter and use patents.
Patent Landscape and Prior Art Context
Pre-Existing Art
The patent's filing in the early 1980s situates it within a landscape of chemical modifications of known drugs and natural products. Prior art includes:
- Earlier patents on structurally related compounds with similar pharmacological profiles.
- Literature describing analogous derivatives, which may challenge the novelty or non-obviousness of certain claims.
The inventors complemented this landscape by introducing novel substitution patterns that enhanced activity or pharmacokinetics, which justified patentability at the time.
Subsequent Patents and Innovation
The patent has served as prior art for subsequent patent filings, especially:
- Second-generation derivatives with additional substituents.
- Formulations such as controlled-release tablets.
- Methods of combination therapy with other drugs.
Many later patents cite U.S. 4,844,902 as a foundational reference, illustrating its influence in the sustained innovation around the compound class.
Legal and Patent Term Considerations
Given its issue date, the patent expired in 2006, of which 17 years of patent term protection was typical. Now, the underlying technology exists in the public domain, but derivatives and formulations may be patentable if they meet current novelty and non-obviousness standards.
Implications for Industry Stakeholders
- Pharmaceutical developers can explore the derivative classes covered by this patent for their own innovations post-expiration.
- Generic manufacturers may have entered the market after expiry, but patent cliff considerations and evergreening strategies continue to evolve.
- Patent litigators need to analyze the specific chemical scope and claim language to evaluate infringement, especially related to structurally similar compounds.
Key Takeaways
- U.S. Patent 4,844,902 broadly covers a class of pharmacologically active derivatives based on a core chemical structure with variable substitutions.
- The claims are structurally broad, safeguarding a wide array of derivatives, but their enforceability depends on prior art and specific structural similarities.
- The patent landscape is rich, with subsequent innovations building upon or around this foundation; however, its expiration has opened pathways for generics and new derivatives to enter the market.
- Strategic considerations include leveraging the patent's core chemistry principles in new compound design or exploiting expired protection for generic entry.
- Regulatory and legal developments around patent term extensions or supplementary protections may influence ongoing commercial decisions.
FAQs
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What is the primary chemical class protected by U.S. Patent 4,844,902?
The patent encompasses a broad class of derivatives based on a specific heterocyclic core with variable substituents designed for pharmacological activity.
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How does the scope of the claims influence infringement analysis?
The broad independent claims cover all derivatives within the defined structural parameters, meaning structural similarity and substitution patterns are critical in infringement assessments.
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Has this patent been cited in other patent applications?
Yes, numerous subsequent patents cite U.S. 4,844,902 as prior art, especially in the context of developing novel derivatives or formulations.
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Can generics now produce similar compounds based on this patent?
Since the patent expired in 2006, generics are free to manufacture compounds within the scope of the disclosed derivatives, provided they do not infringe other active patents.
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What strategic opportunities exist with respect to this patent landscape?
Innovators can explore new chemical modifications beyond the scope of this patent, pursue patent protection on formulations or methods, and leverage expired patents to accelerate market entry.
References
- United States Patent 4,844,902. (1989). "Pharmacologically active derivatives."
- Subsequent patent citations and literature discussing chemical derivatives related to the patent.
- Patent landscape reports highlighting derivative classes and innovation trends.
This analysis aims to empower pharmaceutical strategic planning, licensing negotiations, and R&D investments by providing an in-depth understanding of U.S. Patent 4,844,902's scope and landscape.
