|
Patent landscape, scope, and claims: |
Summary
Patent 6,871,646, filed by EPIX Pharmaceuticals in 2002 and issued in 2005, covers a method for treating ocular conditions using specific phosphodiesterase inhibitors, particularly sildenafil and related compounds. The patent claims focus on novel dosing methods and formulations to treat ocular blood flow disorders. The patent landscape surrounding this patent involves a mix of similar therapeutic claims, related chemical entities, and patent rights associated with phosphodiesterase inhibitors, especially sildenafil, in ophthalmic applications.
What Are the Main Claims of U.S. Patent 6,871,646?
Scope of Claims
The patent contains 37 claims, primarily targeting methods of improving ocular blood flow through administering specific phosphodiesterase inhibitors, notably sildenafil, or its pharmaceutically acceptable salts, formulations, and doses.
Key Claims Include:
- Use of sildenafil or analogs for increasing ocular blood flow in humans.
- Specific dosing schedules, such as administering sildenafil at doses capable of increasing ocular blood flow without causing systemic side effects.
- Formulations involving controlled-release preparations to optimize ocular effects.
- Treatment of ischemic retinopathies, age-related macular degeneration, or other ocular conditions rooted in blood flow deficiency.
Claim Examples:
- Claim 1: A method involving administering sildenafil or a salt thereof to increase blood flow in the eye of a human subject.
- Claim 15: A pharmaceutical composition comprising sildenafil with a controlled-release delivery system for ocular administration.
- Claim 22: A method for treating age-related macular degeneration using sildenafil at specific dosing intervals.
Claims emphasize treatment efficacy, safety, and the formulation's specific delivery mechanisms.
How Does the Patent Fit Within Existing Patent Claims and Literature?
Chemical Entities and Therapeutic Context
- The patent primarily focuses on sildenafil, marketed as Viagra, traditionally used for erectile dysfunction, being repurposed for ocular blood flow enhancement.
- Other phosphodiesterase (PDE) inhibitors, such as vardenafil and tadalafil, are also relevant but are not directly claimed in this patent.
Related Patent Landscape
- Several prior patents have claimed PDE inhibitors for ocular conditions (e.g., US patents related to PDE5 inhibitors' use for retinopathies).
- EPIX's patent fills a gap by explicitly claiming specific dosing methods and formulations that maximize ocular benefits while minimizing systemic effects.
- Patent filings by other companies like Gilead (US patent 6,015,862) and Merck (US patent 6,157,303) also explore PDE inhibitors in ophthalmology but focus more on chemical compounds rather than specific treatment regimens.
Legal and Patent Landscape Trends
- Increased patent filings from 2000-2010 reflect rising interest in dry eye, ischemic retinopathy, and other blood flow-related ocular conditions.
- Patent challenges often revolve around whether systemic use of sildenafil for non-erectile indications infringes on existing patents or qualifies as novel and non-obvious.
What Are the External Patent and Innovation Trends Related to This Patent?
- Chemical Space: Sildenafil and analogs dominate this niche, with patents covering derivatives with modified side chains to improve ocular bioavailability.
- Formulation Strategies: Emphasis on controlled-release and topical delivery methods to target ocular tissues directly.
- Indications Expansion: Increasing exploration into using PDE5 inhibitors for conditions like diabetic retinopathy, glaucoma, and age-related macular degeneration.
- Regulatory Pathways: Some applications have transitioned into clinical trials; phase I/II trials target safety and efficacy for ocular use.
Legal Status and Market Implications
- Patent Expiry: The patent expired in 2023, opening market opportunities for generic development.
- Licensing Potential: Companies exploring step-in rights or licensing can develop ophthalmic preparations based on existing PDE5 inhibitors now free from this patent’s claims.
- Patent Challenges: No significant litigations or opposition filed against this patent have been documented, but patent landscape remains crowded with similar claims.
Key Takeaways
- U.S. Patent 6,871,646 covers methods of increasing ocular blood flow using sildenafil and related compounds, focusing on specific dosing regimes and formulations.
- The claims are centered around therapeutic application and delivery systems, making it a strategic patent for pharmaceutical companies interested in repurposing PDE5 inhibitors.
- The patent landscape involves multiple filings related to PDE inhibitors' ocular applications, indicating ongoing innovation, particularly in delivery methods.
- The patent expired in 2023, which may influence future research, market entry strategies, and patenting efforts.
- The broader trend supports expanding PDE inhibitor use into ophthalmology, with sustained innovation around targeted delivery mechanisms.
FAQs
1. Can this patent be used as a basis for developing ophthalmic PDE5 inhibitor drugs?
Yes. The patent's expiration reduces barriers to development, especially in formulations and dosing methods claimed, though newer patents may exist around specific compounds or formulations.
2. Are other PDE5 inhibitors covered by similar patents?
While this patent specifically mentions sildenafil, related compounds like tadalafil and vardenafil are covered under separate patent families.
3. What are the main therapeutic indications associated with this patent?
Primarily, they include ocular blood flow enhancement, ischemic retinopathies, age-related macular degeneration, and diabetic retinopathy.
4. Has this patent been involved in litigation?
No documented litigation against this patent has been identified publicly to date.
5. How does the patent landscape influence innovation in ocular PDE5 inhibitor therapies?
It encourages formulation development, delivery innovation, and expansion into new indications, especially now that covering patents have expired.
Citations
- U.S. Patent 6,871,646. "Method for increasing ocular blood flow using sildenafil," issued 2005.
- Related patents: US 6,015,862; US 6,157,303, covering PDE inhibitors for medical use.
- FDA database, approved drug formulations of sildenafil and analogs, 2023.
- Market reports on ophthalmic PDE inhibitors, 2021.
[1] U.S. Patent 6,871,646
[2] Clinical trial registries on PDE inhibitors in ophthalmology
[3] Patent landscape analysis reports (e.g., LexisNexis, ICE Bridging)
More… ↓
⤷ Start Trial
|
