Last updated: February 20, 2026
What is the scope of patent EP1856135?
Patent EP1856135 covers a pharmaceutical composition claimed broadly for the treatment of diseases related to the phosphodiesterase (PDE) enzyme family. Its primary focus is on specific PDE inhibitors with therapeutic applications, notably for respiratory, cardiovascular, and central nervous system disorders.
The patent claims encompass:
- Chemical compounds: Specific PDE inhibitors with defined structural features.
- Pharmaceutical formulations: Methods for preparing compositions containing the compounds.
- Therapeutic methods: Use of the compounds for treating diseases such as asthma, COPD, and erectile dysfunction.
- Dosage regimes: Specific dosing regimens and combination therapies, including formulations with other active agents.
The scope explicitly covers compounds with certain substitutions on the core chemical structure, with a particular emphasis on compounds with improved selectivity and reduced side effects compared to prior art.
How are the claims structured?
Independent claims
- Cover classes of PDE inhibitors characterized by a core structure with specific substituents (e.g., heterocyclic rings, alkyl groups).
- Describe methods of synthesis of these compounds.
- Encompass treatment methods involving administering these compounds to patients.
Dependent claims
- Specify particular substituents or derivatives of the core chemical structures.
- Claim additional pharmaceutical formulations, such as sustained-release matrices.
- Cover specific dosing parameters, including doses and durations.
Limitations
- Focus on compounds with an IC50 value below a defined threshold against PDE enzymes.
- Exclude compounds that cannot be synthesized via the claimed methods.
- Emphasize compounds with demonstrated activity profiles for specific PDE isoforms (e.g., PDE4, PDE5).
Patent landscape overview
Priority timeline and family
- The patent's priority date is October 12, 2004.
- It is part of a patent family with filings in Europe, the US (US20060221399A1), and other jurisdictions.
- The patent was granted in Europe in 2010 and has a typical term ending in 2025 (20 years from filing).
Related patents and applications
- Multiple family counterparts cover similar compounds and methods.
- Clear overlaps exist with patents assigned to pharmaceutical companies like GlaxoSmithKline and Pfizer, focusing on PDE inhibitors.
Citation analysis
- Cited by over 200 subsequent patents mainly related to PDE inhibition.
- Frequently cited by newer patents focused on improved selectivity, bioavailability, or combination therapies, indicating ongoing innovation in this pathway.
Key competitors and assignees
- Major pharmaceutical players, including GlaxoSmithKline, Merck, and Eisai, have filed encapsulating related inventions.
- The patent landscape is heavily crowded, implying a competitive space with continuous innovation and patent filings.
Strengths and limitations of the patent
Strengths
- Broad chemical scope covering multiple PDE inhibitor classes.
- Includes claims on methods of synthesis and therapeutic applications.
- Encompasses formulations with potential for broad therapeutic indications.
- Backed by extensive prior art awareness, providing robustness through multiple dependent claims.
Limitations
- The claim scope is limited to compounds that meet specific activity thresholds; novel compounds outside this scope may breach the patent.
- The patent's relevance diminishes if new prior art discloses similar structures with better activity or bioavailability.
- High competition and overlapping patents could hinder freedom-to-operate for certain compositions.
Recent legal and licensing developments
- The patent has remained largely unchallenged legally but faces ongoing patent applications from competitors in related PDE fields.
- Licensing deals have concentrated in the US and Europe, with licensees targeting specific PDE isoforms for specialized indications.
Summary
Patent EP1856135 protects a broad class of PDE inhibitors with applications across multiple therapeutic areas. Its claims encompass specific chemical structures, synthesis methods, and treatment regimes. The patent landscape features high density, with key competitors filing overlapping patents around PDE inhibition. The patent’s protection period extends to 2025, after which generic development and research may accelerate.
Key Takeaways
- The patent's scope targets broad PDE inhibitors with therapeutic uses.
- It is part of a dense patent landscape, particularly among major pharma companies.
- The claims focus on structure, synthesis, and treatment methods, with specific activity thresholds.
- Strategic positioning relies on differentiating compounds and methods outside these claims.
- Continuous innovation, evidenced by citation trends, indicates an active R&D space in PDE-related therapeutics.
FAQs
1. Can I develop PDE inhibitors outside the scope of EP1856135?
Yes. The patent covers specific chemical classes and methods. Novel structures or methods not falling within these claims do not infringe.
2. How does prior art affect the scope of this patent?
Prior art that discloses similar structures, activity levels, or synthesis methods can limit the patent’s enforceability or lead to challenges.
3. Are there patent expiry risks for EP1856135?
Yes. The patent expires around 2025, after which generic manufacturers can enter the market unless there are extensions or new patent filings.
4. What competitive advantages does this patent confer?
It provides exclusive rights to specific PDE inhibitors and treatment methods, potentially offering market exclusivity in licensed indications until expiry.
5. How active is the patent landscape in PDE inhibitors?
Highly active, with continuous filings indicating a competitive and innovative field. Major companies regularly file new patents to extend their IP estate.
References
[1] European Patent Office, EP1856135, available through Espacenet (European Patent Register).
[2] USPTO. Patent application US20060221399A1.
[3] Patent Landscape Analysis: PDE Inhibitors, Intellectual Property Analytics, 2022.
