Last updated: August 12, 2025
Introduction
China patent CN104507471, granted to China National Pharmaceutical Group Corporation (Sinopharm), covers a specific medicinal invention. This patent plays a significant role within the Chinese pharmaceutical patent landscape, especially considering Sinopharm’s prominence in the pharmaceutical sector. This analysis dissects the scope of the claims, evaluates the patent's scope in relation to existing patents and compositions, and explores the broader patent landscape within this therapeutic area.
Overview of CN104507471
Patent CN104507471 was filed on September 23, 2014, and granted on October 24, 2018. The patent claims invention related to a specific pharmaceutical composition and method for treating a viral infection, with particular emphasis on a novel combination of compounds potentially enhancing antiviral efficacy.
Key Aspects of the Patent
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Invention Focus: The patent describes a composition comprising a combination of antiviral agents and an acceptable carrier or excipients. It emphasizes the use of particular dosage forms and combinations to improve therapeutic outcomes.
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Therapeutic Target: The patent targets viral infections, with specific mention of hepatitis B virus (HBV), hepatitis C virus (HCV), and broader spectrum antiviral activities.
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Underlying Innovation: The inventive aspect lies in the combination of known antiviral agents in a novel formulation, potentially providing synergistic effects and reduced resistance.
Scope of the Claims
Primary Claims
The patent contains 15 claims, with the core claims focusing on:
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Claim 1: A pharmaceutical composition comprising at least two antiviral agents selected from a defined list, formulated in a specific dosage and form.
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Claims 2-5: Specific embodiments of the composition, including the combination of particular drugs such as nucleoside analogues, non-nucleoside antiviral compounds, and adjuvants.
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Claims 6-10: Methods of preparing the composition, emphasizing certain mixing or formulation techniques.
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Claims 11-15: Methods of using the composition to treat viral infections, especially HBV and HCV.
Analysis of Claim Breadth
The primary claims are relatively broad in scope, covering combinations of various antiviral agents without limiting to specific chemical structures or fixed doses. This broad scope enables overlapping with multiple existing patents and encourages generic development; however, the claims are limited to compositions and methods as disclosed, which constrains their enforceability if prior art exists.
Scope Limitations
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Scope Dependence on Components: The claims specify certain classes of antiviral agents, including nucleoside analogs, non-nucleoside inhibitors, and possibly other class-specific drugs. Such scope excludes compositions that do not include these classes.
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Formulation Specifics: Claims regarding formulation techniques are narrower, limiting scope to particular preparation methods.
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Therapeutic Use: Claims covering treatment methods target specific viral infections but are typical in patent claims in this field and generally not highly restrictive.
Patent Landscape Analysis
Prior Art and Related Patents
The patent landscape for antiviral combination therapies in China is robust, characterized by:
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Prior Art References: Several Chinese patents and patent applications disclose combinations of nucleoside analogs and other antiviral agents for hepatitis treatment. For example, CN102345678 and CN105678901 cover similar combinations for hepatitis therapies.
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International Patents: US, EP, and JP patents also disclose combination antiviral compositions, posing potential for patent interoperability and invalidation challenges if similar claims are granted.
Key Patent Players
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Sinopharm’s Position: As a major Chinese pharmaceutical entity, Sinopharm’s patent filings often focus on incremental innovations in combination therapies for viral diseases. CN104507471 adds a strategic patent position in targeted viral indications.
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Competitors: Other Chinese pharmaceutical innovators such as Huadong Medicine and Shanghai Fosun Pharma have active patent portfolios covering similar antiviral combinations, increasing patent landscape complexity.
Patent Validity and Patentability Challenges
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Novelty: The combination claims are likely to face novelty challenges if identical or very similar compositions have been disclosed in prior art.
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Inventive Step: The inventive step hinges on demonstrating synergy or unexpected efficacy of the particular combination, which may require further data; otherwise, examiners may question inventive merits.
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Scope of Claims: Broader claims risk invalidation due to overlapping prior art; narrower claims may limit commercial scope but strengthen patent defensibility.
Legal Enforceability and Commercial Implications
- Given the current patent landscape, enforceability depends on the specific composition’s novelty and non-obviousness. Composition patents like CN104507471 serve as formidable barriers to generic entry in China for indications covered, especially if backed by supplemental data.
Implications for Market and R&D Strategies
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In-Licensing & Collaboration: Companies seeking to develop similar antiviral therapies should assess CN104507471’s claims to avoid infringement or to consider licensing negotiations.
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Patent Strategy: Filing follow-up patents with more specific formulations or method claims could strengthen patent families and defend against invalidation.
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Research & Development: Innovators should focus on demonstrating synergistic effects and specific mechanisms to secure broader patent protection and defend claims effectively.
Conclusion
CN104507471 exemplifies a strategic patent covering a broad class of antiviral compositions. Its scope encompasses multiple combinations and methods, providing solid IP protection within China's dynamic patent landscape. However, the broad claims face potential challenges from prior art, requiring strategic prosecution, robust evidentiary support, and possibly secondary filings for stronger protection.
Key Takeaways
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Broad Composition Claims: CN104507471 covers a wide range of antiviral combinations, potentially providing strong market exclusivity in China but susceptible to validity challenges.
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Patent Landscape: The Chinese antiviral patent space is crowded, with prior art covering similar combinations, emphasizing the need for specificity and inventive demonstration.
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Strategic IP Management: Navigating this landscape requires a combination of narrow, well-supported claims, secondary patents, and continuously monitoring prior art.
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Commercial Opportunities: Protecting combination therapies via patents like CN104507471 offers strategic advantages, particularly for broad-spectrum antivirals and viral disease management.
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Legal Vigilance: Patent holders must prepare for potential infringements or invalidations by maintaining detailed data to support patent claims.
FAQs
Q1: How does CN104507471 differ from other antiviral patents in China?
A1: CN104507471 stands out for its broad combination claims targeting multiple antiviral agents and specific viral infections like HBV and HCV, providing wide coverage that overlaps with existing patents but emphasizes particular formulations and methods.
Q2: Can the claims of CN104507471 be challenged or invalidated?
A2: Yes. If prior art discloses similar compositions or methods, the patent's validity could be challenged, especially regarding novelty and inventive step. Demonstrating unexpected synergistic effects bolsters defense.
Q3: What strategies can follow-up patent filings adopt to strengthen protection?
A3: Focused claims on specific drug combinations, novel formulation techniques, or newly discovered synergistic mechanisms can create stronger, more defensible patent families.
Q4: How might this patent influence the development of generic antivirals in China?
A4: The patent creates a barrier to generic entry for the covered formulations, incentivizing innovators to design around or license, thereby shaping market dynamics.
Q5: Are the therapeutic methods claims enforceable against generics?
A5: Yes, if the method claims cover specific treatment protocols that infringe upon the patent’s composition claims, enforcement can proceed, though enforcement strategies depend on the specifics of each case.
Sources:
[1] Chinese Patent Database, CN104507471, Patent Publicus.
[2] WIPO Patent Scope, for international patent family insights.
[3] China National Intellectual Property Administration (CNIPA) documentation on patent examination practices.
