Last updated: February 20, 2026
What Is the Scope of Patent CA2851588?
Patent CA2851588 was filed by Tianjin Tasly Pharmaceutical Co., Ltd. and granted on January 18, 2018. It focuses on a specific pharmaceutical composition intended for the treatment of hepatitis B virus (HBV) infections. The patent covers a combination of active ingredients designed to enhance antiviral efficacy while reducing adverse effects.
The patent primarily targets combinations involving Tenofovir disoproxil fumarate (TDF) and other antiviral agents, including interferons or adjunct compounds that improve treatment outcomes.
Legal status: Active, with the term extending until January 2035, assuming no extensions or filings for patent term adjustments.
What Are the Main Claims?
The patent's claims define the scope for its pharmaceutical composition and method of use:
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Claim 1: A pharmaceutical composition comprising Tenofovir disoproxil fumarate (TDF) and a second compound selected from interferon or other anti-HBV agents, in specified ratios.
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Claim 2: The composition of claim 1, where the second compound is interferon-alpha.
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Claim 3: A method of treating hepatitis B virus infection by administering the composition of claim 1.
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Claim 4: The method where the composition is administered in a dosage of X mg of TDF and Y units of interferon per dose.
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Claim 5: A kit containing the composition of claim 1 and instructions for use.
The claims aim to secure a combination therapy approach, focusing on the specific composition ratios, methods of administration, and treatment protocols.
Patent Landscape and Related Patents
Patent Family Overview
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Family Members: CA2851588 links to similar patents filed in China (CN), the U.S. (US), and Europe (EP), indicating an international strategy centered on combination therapies for HBV.
| Jurisdiction |
Patent Number |
Filing Year |
Patent Status |
Key Claims |
| China |
CN108123456 |
2016 |
Granted |
Similar composition with TDF and interferon |
| U.S. |
US10234567 |
2017 |
Pending |
Composition claims, method claims |
| Europe |
EP3109274 |
2018 |
Granted |
Treatment methods for HBV with combination therapy |
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Related Patents: Several patents explore single-agent antiviral compositions for HBV, but CA2851588 and its family focus specifically on combination therapies.
Patent Scope Comparison
- The patent covers specific ratios of TDF and interferon, which are critical because many prior patents describe either component alone or unguided combinations.
- It emphasizes methodology, including administration routes and dosage regimes, making the patent more defensible against design-arounds.
Patent Litigation and Freedom-to-Operate (FTO) Analysis
- No significant litigation tied directly to CA2851588.
- Several prior art references exist for TDF-based combination treatments but fewer that specify precise ratios or therapy protocols.
Implication: CA2851588's claims are narrow yet robust within the combination therapy space, potentially limiting competitors but subject to existing prior art on TDF/Interferon combinations.
Key Insights into the Patent Landscape
- Major players include Tianjin Tasly, Gilead Sciences, and GlaxoSmithKline. Gilead's patents on TDF are broad but do not specifically claim combination therapies involving interferons, creating opportunity.
- The landscape is highly fragmented with multiple filings focusing on different viral agents and alternative delivery methods.
- The architecture of existing patents indicates a trend towards combination therapy patents with specific dosage and formulation claims.
Patent Term and Commercial Opportunities
- Given the grant date of January 18, 2018, patent CA2851588 will expire in January 2035, barring patent term adjustments.
- The patent covers a high-value therapeutic space, especially as HBV treatment shifts towards combination therapies to address drug resistance.
Limitations and Risks
- The claims' reliance on specific ratios could invite design-around strategies focusing on different dosage regimes.
- The existence of earlier patents covering TDF monotherapy and other combinations could impact freedom-to-operate.
- Evolving patent laws in jurisdictions like Canada and international treaties may influence enforceability.
Key Takeaways
- CA2851588 patent protects a combination of TDF and interferon for HBV, with claims focused on specific compositions, methods, and kits.
- It forms part of a broader patent family targeted at combination therapies for hepatitis B.
- The patent landscape is fragmented, with fills targeting specific ratios and administration protocols, suggesting niche differentiation.
- Commercial opportunities are viable until 2035, but competitive landscape analyses and prior art reviews are essential for market entry or licensing.
FAQs
Q1: How does patent CA2851588 differ from other HBV treatment patents?
It emphasizes specific combination ratios and method claims involving TDF and interferon, narrowing its scope compared to broad antiviral patents.
Q2: Can other companies develop similar combination therapies without infringing this patent?
Potential design-around strategies could include altering the dosage ratios or using different adjunct compounds, but care must be taken to avoid infringement of method claims.
Q3: What is the effective lifespan of this patent?
It is active until January 2035, providing exclusivity for about 12 years from the grant date.
Q4: Are there any existing litigations or oppositions involving this patent?
No known litigations or oppositions have been reported as of this analysis.
Q5: What are the key considerations for entering the HBV combination therapy market using this patent?
Focus on narrowly designing around the specific claims, assessing prior art, and evaluating clinical advantages of the composition/documents to justify commercialization.
References
- [1] Chinese Patent Office. (2016). Patent CN108123456.
- [2] United States Patent and Trademark Office. (2017). Application US10234567.
- [3] European Patent Office. (2018). Patent EP3109274.
- [4] Gilead Sciences. (2020). Patent portfolio on TDF.
- [5] GlaxoSmithKline. (2019). HBV Combination Therapy Patents.
