Patent Analysis for US Patent 4,661,493
What is the Scope and Content of US Patent 4,661,493?
US Patent 4,661,493 was granted on April 28, 1987, to Novo Nordisk for a "Recombinant DNA process for production of insulin and insulin analogs." The patent claims cover recombinant DNA techniques to produce insulin and analogs with specific amino acid sequences.
Claims Overview
The patent includes eight claims, with the primary claim (Claim 1) defining a method for producing human insulin using recombinant DNA technology:
- Claim 1: A process involving inserting a DNA sequence coding for human insulin into a bacterial host, allowing expression of insulin precursors, and processing to produce mature insulin.
Secondary claims specify particular vectors, hosts, and processing steps, including:
- Use of plasmid vectors.
- Expression in Escherichia coli.
- Specific processing methods for proinsulin converting into insulin.
Scope of Claims
The claims focus on recombinant DNA methods for insulin production, encompassing:
- The DNA sequences coding for human insulin.
- Vectors containing these sequences.
- Host cells, primarily E. coli, transformed with the vectors.
- Methods for expressing and processing insulin precursors into active insulin.
The scope appears broad for the time, covering various vectors, hosts, and processing steps, but narrowly focused on recombinant DNA techniques for insulin biosynthesis.
How Does This Patent Fit Into the Broader Patent Landscape?
Patent Family and Related Patents
US 4,661,493 is part of a family of patents filed by Novo Nordisk. Key related filings include:
- EP 0 207 153 (European Patent), also titled for recombinant insulin.
- WO 86/01624 (World Patent), covering recombinant DNA methods for insulin production.
These patents collectively secured intellectual property rights for recombinant insulin technology across multiple jurisdictions.
Competitor Patents
Major competitors, such as Eli Lilly (e.g., US Patent 4,703,008) and Genentech, filed similar patents on insulin analogs and production methods during the same period. The landscape shows overlapping claims on:
- DNA sequences coding for insulin and analogs.
- Expression vectors and hosts.
- Processing steps for converting precursors into mature insulin.
Patent Expiry and Freedom to Operate
Most patents filed in the 1980s, including US 4,661,493, typically have 17-year patent terms from the issue date, expired by 2004. This expiration opened the market for generic insulin production and biosimilar competitors.
However, newer patents related to insulin analogs or formulations may still be in force, restricting certain modifications.
Trends and Developments in the Patent Landscape
Shift Toward Insulin Analogs and Delivery Devices
Post-2000, the focus shifted beyond recombinant DNA methods to include:
- Insulin analogs with altered pharmacokinetics for better glucose control.
- Delivery devices such as insulin pens and pumps.
- Biosimilars and manufacturing process innovations.
Patent Clusters
Analysis shows several clusters:
- Original recombinant DNA production methods.
- Process improvements for higher yield or purity.
- Insulin analogs with modified amino acid sequences.
- Delivery system patents.
Legal Status and Litigation
There have been few major litigations directly involving US 4,661,493, mainly because it expired early in the biosimilar era. Patent disputes currently center on newer formulations, analogs, and delivery methods.
Implications for R&D and Commercial Strategy
- Original process patents like US 4,661,493 are now public domain, allowing biosimilar development.
- Patents on insulin analogs and delivery methods provide exclusivity, influencing market dynamics.
- Understanding the historical scope aids in designing new, non-infringing innovations.
Summary Table: Patent Landscape Highlights
| Aspect |
Details |
| Patent Number |
4,661,493 |
| Filing Date |
March 8, 1984 |
| Issue Date |
April 28, 1987 |
| Expiry |
2004 (patent term) |
| Main Claims |
Recombinant DNA methods for human insulin production |
| Family Members |
European, PCT, Japanese filings |
| Related Patents |
US 4,703,008 (Lilly), WO patents (Genentech) |
| Post-expiry Patents |
Focus shifted to analogs, delivery methods |
Key Takeaways
- US 4,661,493 covers early recombinant DNA processes for insulin synthesis, with a broad scope for DNA sequences, vectors, and hosts.
- The patent expired by 2004, opening the market for biosimilar insulin manufacturers.
- The patent landscape evolved towards insulin analogs, delivery systems, and manufacturing improvements.
- Modern patent strategies for insulin focus less on basic recombinant methods and more on modifications, formulations, and delivery technologies.
- Ongoing patent protections in the insulin space now predominantly relate to novel analogs and device innovations.
FAQs
1. When does the patent US 4,661,493 expire?
It expired in 2004, 17 years after its issue date in 1987.
2. Can a company now produce recombinant human insulin based on this patent?
Yes. The patent rights have expired, removing infringement concerns for recombinant human insulin production based on the methods disclosed.
3. Are there still active patents covering insulin analogs?
Yes. Patents on specific insulin analogs, process improvements, and delivery devices remain active and enforceable.
4. What implications did the patent's expiration have on the market?
It allowed biosimilar and generic insulin manufacturers to enter the market, increasing competition and reducing prices.
5. How does the scope of US 4,661,493 compare to later insulin patents?
It covers fundamental recombinant DNA methods, while later patents focus on specific modifications, formulations, and devices, with narrower scopes.
References
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[1] U.S. Patent and Trademark Office. Patent Full Text and Image Database. (1987). US Patent 4,661,493.
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[2] European Patent Office. Patent EP0207153B1. (1991).
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[3] World Intellectual Property Organization. WO 86/01624. (1986).
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[4] Li, Z., & Wu, L. (2002). The development of insulin analogs: An overview. Diabetes & Metabolism, 20(2), 54–60.
