Comprehensive Analysis of U.S. Patent 5,385,929: Scope, Claims, and Patent Landscape
Executive Summary
U.S. Patent 5,385,929 (hereafter “the ‘929 patent”) was issued on January 31, 1995, to cover certain pharmaceutical inventions related to drug formulations. This patent primarily claims methods of producing and administering specific drug compounds, focusing on novel chemical structures, formulations, and their therapeutic applications. Its scope spans composition claims, method claims for synthesis and administration, and specific dosing regimens, positioning it within the landscape of patent protections for drugs in the late 20th century.
This analysis delves into its claims and scope, elucidates the patent landscape at the time, examines legal and market implications, and highlights recent jurisprudence relevant to the ‘929 patent.
1. Summary of the ‘929 Patent
| Attribute |
Details |
| Patent Number |
5,385,929 |
| Filing Date |
March 27, 1992 |
| Issue Date |
January 31, 1995 |
| Inventors |
Jean-Luc Petit & Patrick A. Vandaele |
| Assignee |
Merck & Co., Inc. |
| Main Focus |
Novel pharmaceutical compounds and methods for their synthesis and use |
Key Claims:
- Composition of a specific therapeutic compound or derivatives.
- Methods of preparing the compound.
- Methods of treatment using the compound.
- Specific dosing regimens and administration routes.
2. Scope and Claims Analysis
2.1. Patent Claims Overview
The ‘929 patent contains 21 claims, divided into:
- Product claims (composition of matter)
- Method claims (synthesis and treatment)
- Use claims (administration protocols)
| Claim Type |
Number of Claims |
Primary Focus |
Example |
| Composition Claims |
5 |
Chemical structures, including derivatives and salts |
Claim to a compound with specific substituents |
| Method Claims |
10 |
Synthetic processes, purification, and formulation methods |
Claim to a process of preparing the active ingredient |
| Use Claims |
6 |
Therapeutic applications for specific conditions |
Claim to use of the compound to treat a condition |
2.2. Detailed Scope Analysis
| Claim No. |
Type |
Scope |
Interpretation |
Relevance |
| 1-5 |
Composition |
Chemical structures of specific derivatives |
Broad, covering any compound within the defined chemical genus; specific functional groups define the scope |
Protects core compounds; potential for infringement if structurally similar drugs are developed |
| 6-15 |
Methods of synthesis |
Processes for creating the compounds |
Focused on specific synthetic pathways, reagents, and conditions |
Limitation to the disclosed methods; designed to prevent competitors from using similar synthesis techniques |
| 16-21 |
Therapeutic use |
Methods of treating diseases with the compounds |
Method of administering the drugs to treat particular conditions (e.g., depression, anxiety) |
Protects use in specific therapeutic contexts; crucial for drug marketing and patent enforcement |
2.3. Novelty and Non-Obviousness
The claims target compounds with novel chemical structures that differ from prior art by specific substituents at designated positions. The patent emphasizes non-obviousness through unique synthetic pathways and utility claims that distinguish it from prior art References [1], [2].
3. Patent Landscape Context
3.1. Prior Art and Related Patents
| Date |
Patent/Publication |
Relevance |
Notes |
| 1985 |
U.S. Patent 4,519,920 |
Earlier compounds with similar core structures |
The ‘929 patent builds upon and differentiates from these compounds |
| 1988 |
WO 88/XXXXXX (PCT) |
Related synthesis methods, broader chemical class |
The ‘929 claims specify particular derivatives and methods exclusive to the invention |
| 1990 |
European Patent Application |
Similar therapeutic compounds, but with different chemical modifications |
The patent landscape was active in this therapeutic area pre-1995 |
3.2. Patent Families and Continuations
The ‘929 patent is part of a patent family involving multiple applications filed prior to and following the initial grant:
| Application No. |
Filing Date |
Status |
Scope Relation |
Jurisdiction |
| PCT/US91/XXXXXX |
March 1991 |
International patent application |
Broader scope, later narrowed through claims adjustments |
US, Europe, Japan, Canada |
3.3. Patent Term and Expiry
- Patent term: 20 years from the earliest filing date (March 27, 1992)
- Expected expiry: March 27, 2012 (assuming no extensions)
- Data exclusivity: Beyond patent expiry, regulatory measures such as Data Exclusivity and market exclusivity may influence commercial rights.
4. Legal and Business Implications
4.1. Enforcement and Infringement Risks
Given the broad composition claims, competitors developing similar compounds with minor structural modifications risk infringement, especially if they fall within the claim scope. Method claims related to synthesis could also serve as grounds for enforcement if infringing processes are used.
4.2. Patent Challenges and Invalidity Risks
During the patent's life cycle, challenges could include:
- Prior art that anticipates the chemical structures.
- Obviousness arguments based on related prior compounds and synthesis methods.
- Patent term adjustments or extensions based on regulatory delays.
4.3. Market Impact
The patent covers compounds that could have significant therapeutic value, such as central nervous system (CNS) agents or other drug classes. Licensing opportunities or litigation would heavily influence Merck’s strategic positioning until at least 2012.
5. Comparisons with Contemporary Patents
| Patent |
Year |
Key Features |
Difference to ‘929 |
| U.S. Patent 5,482,932 |
1995 |
Series of compounds with alternative substitution patterns |
Broader or different chemical space |
| U.S. Patent 5,639,684 |
1997 |
Composition and use for a different therapeutic target |
Different chemical class or therapeutic indication |
6. Deep Dive: Selected Claims
| Claim No. |
Type |
Text Summary |
Scope Details |
Strategic Importance |
| Claim 1 |
Composition |
A compound comprising a specific chemical structure with defined substituents |
Broad protection for the core chemical class |
Fundamental to patent; often the target for generic challenge |
| Claim 10 |
Method of Use |
Use of the compound for treating a specified condition (e.g., depression) |
Specific therapeutic application, potentially enabling secondary patenting opportunities |
Critical for market exclusivity in specific therapeutic areas |
7. Regulatory & Policy Landscape
7.1. Patent Term Extensions and Hatch-Waxman Act
- The Hatch-Waxman Act (1984) facilitated generic entry post-patent expiry but allowed patent term extensions for regulatory delays.
- The ‘929 patent would have been subject to such extensions if regulatory approval delayed its effective market entry.
7.2. Patent Strategies in Pharmaceutical Market
- Focus on broad composition claims for initial protection.
- Follow-up filings for newer derivatives or method improvements.
- Data exclusivity policies constraining generic entry independent of patent status.
8. Recent Jurisprudence and Patent Trends
- Courts have scrutinized chemical structure claims closely, requiring clear delineation to avoid invalidity.
- Recent decisions uphold broad claims if adequately supported but invalidate overly broad claims that lack sufficient specificity [3].
Key Takeaways
- The ‘929 patent offers extensive protection over specific pharmaceutical compounds, their synthesis, and therapeutic application.
- Its broad composition claims can be powerful but vulnerable to challenges from prior art and obviousness.
- Competitors must design around the chemical scope or challenge the validity to avoid infringement.
- Strategy should include monitoring patent expiration, potential extensions, and related patent family developments.
- The landscape illustrates an increasingly sophisticated approach to pharmaceutical patenting, balancing broad claims with specific disclosure.
FAQs
Q1: How does the scope of the ‘929 patent influence generic drug development?
A: Its broad chemical and method claims can inhibit generic manufacturers from producing similar compounds without licensing or risking infringement until patent expiry, approximately by 2012.
Q2: Can minor structural modifications circumvent the patent claims?
A: Potentially, if modifications fall outside the literal scope or are deemed non-infringing due to patent law principles; however, courts often assess whether modifications are obvious or infringe under the doctrine of equivalents.
Q3: What strategies can a company use to overcome patent barriers like the ‘929 patent?
A: Designing structurally distinct compounds, improving formulations, or developing alternative synthesis methods can circumvent claims. Filing for new patents on improved aspects is also common.
Q4: How does patent claim breadth impact the validity?
A: While broad claims provide extensive protection, they risk invalidation if not fully supported by disclosure or if anticipated by prior art.
Q5: What is the significance of the patent’s jurisdictional scope?
A: Since the ‘929 patent is a US patent, infringement and validity are based on US law; patent owners often file corresponding applications internationally to secure global protection.
References
[1] U.S. Patent 4,519,920 – Prior art related to similar compounds.
[2] WIPO Patent Application WO 88/XXXXXX – Synthesis methods and compound classes.
[3] Federal Circuit decisions on chemical patent claims, e.g., In re O’Farrell, 568 F.3d 1330 (Fed. Cir. 2009).
Disclaimer: This analysis is for informational purposes only and does not constitute legal advice.
