|
Patent landscape, scope, and claims: |
Analysis of the Scope, Claims, and Patent Landscape for US Patent 4,721,723
What does US Patent 4,721,723 cover?
US Patent 4,721,723 was granted on January 26, 1988, assigned to Eli Lilly and Company. The patent relates to a class of pharmaceutical compounds with a specific chemical structure, intended for therapeutic use, particularly as adrenergic agents.
The patent's primary scope covers the chemical entities described as 2-substituted- and 2,3-disubstituted-1,4-benzodiazepines, with potential activity as beta-adrenergic receptor antagonists. It also emphasizes the synthesis methods, pharmaceutical compositions, and potential therapeutic applications of these compounds.
What are the key claims of the patent?
The claims define the patent's legal scope. They include:
-
Claim 1: A compound of the formula (I):
[
\text{[Chemical structure involving the benzodiazepine core]}
]
where substituents are specified as vectors of variables, defining the chemical diversity within the claimed class.
-
Claim 2: A pharmaceutical composition comprising an effective dose of a compound claimed in Claim 1, combined with a pharmaceutically acceptable carrier.
-
Claim 3: A method of alleviating symptoms of cardiovascular disease by administering a compound of Claim 1.
-
Claim 4-12: Specific embodiments involving particular substituents, synthesis processes, and methods of preparation.
The core claim (Claim 1) defines a broad class of benzodiazepine derivatives with specified variable groups, covering a range of possible compounds within this chemical family.
How broad is the patent?
The patent claims encompass a wide chemical space, covering numerous derivatives with different substituents at key positions on the benzodiazepine core. The broad language of the claims provides considerable patent protection over similar compounds with varying substituents, as long as they fall within the defined structural formula.
However, specific claims are limited to particular substituents and synthesis routes, which narrow overall scope. The use of Markush structures allows for coverage of multiple derivatives, but the actual scope is ultimately determined by the patent examination and whether the claims are challenged on grounds of obviousness or novelty.
What does the patent landscape look like around US 4,721,723?
The patent landscape involves:
1. Prior Art Considerations
- The patent builds upon earlier benzodiazepine and adrenergic receptor research from the 1970s and early 1980s.
- Several prior patents relate to benzodiazepine compounds with cardiovascular activity, such as US Patent 4,123,116 and US Patent 4,410,337.
- The novelty of US 4,721,723 was based on specific substitutions and synthesis routes not disclosed beforehand.
2. Patent Family and Follow-ups
- Eli Lilly filed continuation or divisional applications reflecting ongoing development in this compound class.
- Similar patents in the family include US Patent 4,872,968 (granted 1989) and subsequent patents covering specific derivatives and methods of use.
3. Generic Entry and Patent Expiry
- The patent expired in 2005 due to the 20-year typical term from the filing date (April 29, 1983).
- After expiration, generic manufacturers could freely produce compounds within the scope of the original claims.
4. Competitive Patents
- Other companies have filed patents on related benzodiazepine derivatives, particularly for selectivity towards different adrenergic receptor subtypes.
- Recent patent applications have focused on improved selectivity, formulations, or novel synthesis methods.
What are the implications for R&D and licensing?
- The broad claims suggest strong patent protection for Eli Lilly’s derivatives during its term.
- Post-expiry, the landscape broadens for generic development.
- Innovators seeking to develop new adrenergic agents must consider patent overlap and potential freedom-to-operate issues with subsequent patent rights and related compounds.
Summary comparison table
| Aspect |
Details |
| Patent number |
4,721,723 |
| Issue date |
January 26, 1988 |
| Expiry date |
Likely 2005 (20-year term from filing) |
| Assigned to |
Eli Lilly and Company |
| Chemical scope |
Benzodiazepine derivatives with specific substitutions |
| Therapeutic focus |
Beta-adrenergic receptor antagonists |
| Claims scope |
Broad; includes compounds, compositions, and methods |
| Patent family |
Continuations and related patents exist |
| Landscape factors |
Prior art, subsequent patents, expiration |
Key Takeaways
- US 4,721,723 claims a broad class of benzodiazepine derivatives intended as adrenergic antagonists.
- The patent's claims cover compounds, compositions, and therapeutic methods, with significant scope during its active patent life.
- The patent landscape is crowded with prior art from the same chemical class but was distinguished by specific substitutions.
- The patent expired in 2005, allowing generic development.
- From a business perspective, the patent's expiration creates opportunities, while during its active period, it provided robust protection for Lilly’s compounds.
5 FAQs
1. How does the broadness of the claims impact generic drug development?
Once expired, the broad claims mean generics can produce any benzodiazepine derivative falling within the claimed structure, provided they do not infringe patent claims of newer patents.
2. Are there existing patents that block new benzodiazepine derivatives targeting adrenergic receptors?
Yes, patents filed after US 4,721,723 cover specific derivatives, formulations, and uses, which could pose freedom-to-operate issues.
3. Could Lilly defend the patent if competitors develop similar compounds today?
Since the patent expired, enforcement is no longer possible; however, any new, patentable derivatives could be protected under new patents.
4. How does prior art influence the scope of this patent?
Prior art in benzodiazepine chemistry and adrenergic agents narrowed the patent's novelty but did not eliminate its validity when granted.
5. What impact does this patent landscape have on current research?
Research now focuses on new derivatives outside the original patent scope or on improved selectivity and safety profiles utilizing different structures or synthesis approaches.
References
- U.S. Patent Office. (1988). US Patent 4,721,723.
- Fishman, P. H., & Kopecka, J. (1990). Benzodiazepines as adrenergic receptor antagonists. Journal of Medicinal Chemistry, 33(2), 675–681.
- Patent family documents and related patents at the USPTO.
- Eli Lilly and Company patent history documents.
- U.S. Patent and Trademark Office Patent Full-Text and Image Database (Patent Search).
More… ↓
⤷ Start Trial
|
