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Patent landscape, scope, and claims: |
Summary
United States Patent 4,948,805 (hereafter '805 patent), titled "Method for Facilitating Cancer Cell Death and Tumor Inhibition", was granted on August 14, 1990, to The Regents of the University of California. It covers a novel method involving the use of specific antisense oligonucleotides targeting oncogenes, primarily c-myb and c-myc, to inhibit tumor growth. The patent claims methods of administering these antisense compounds for therapeutic purposes, emphasizing their use in cancer treatment. This analysis examines the scope and claims of the '805 patent, maps its patent landscape, evaluates its influence on subsequent patents, and discusses relevant legal and market implications.
Scope and Claims of United States Patent 4,948,805
Overview of Patent Claims
The patent primarily claims:
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Method claims: Administration of antisense oligonucleotides directed against specific oncogene mRNA sequences to inhibit tumor cell proliferation.
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Compounds claims: Synthetic antisense oligonucleotides complementary to targeted oncogene sequences.
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Use claims: The application of these antisense molecules in treating cancers characterized by overexpression of c-myb and c-myc.
Claim Structure and Focus
| Number |
Type |
Description |
Focus Area |
Claim Language |
| 1 |
Method |
Administering antisense oligonucleotides to inhibit tumor growth |
Therapeutic application |
"A method for inhibiting tumor cell proliferation..." |
| 2 |
Compound |
Specific sequences of antisense oligonucleotides |
Chemical composition |
"An antisense oligonucleotide comprising the sequence..." |
| 3 |
Use |
Use of antisense oligonucleotides in cancer treatment |
Indication-specific |
"Use of the oligonucleotide for treating cancers..." |
The broadest claims encompass any antisense oligonucleotide targeting the specified oncogene sequences, with emphasis on sequence complementarity to the mRNA of c-myb and c-myc.
Key Elements of the Claims
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Targeted Oncogenes: c-myb and c-myc, both involved in cell cycle regulation and tumorigenesis.
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Oligonucleotide Details: Typically 15-20 nucleotides in length, designed to bind specifically to the oncogene mRNA.
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Therapeutic Methods: Systemic or local delivery methods such as injection, infusion, or topical application.
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Specificity: Claims emphasize sequence specificity to achieve selective inhibition.
Claim Limitations
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The claims are limited to antisense oligonucleotides with certain sequence complementarity; however, they do not specify a particular chemical backbone, thus potentially covering various backbone chemistries (e.g., phosphorothioate).
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The patent explicitly refers to "antiproliferative effects in tumor cells", maintaining a focus on cancer therapy.
Legal Scope and Potential Patent Infringements
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The broad claims potentially cover all antisense approaches against the targeted oncogenes, regardless of backbone chemistry or method of delivery, provided the sequence complementarity is maintained.
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Limitations: Patent claims do not extend to other gene-inhibition modalities like RNAi or CRISPR, which emerged later.
Patent Landscape for the '805 Patent
Historical Context
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Filed on July 16, 1987, assigned to The Regents of the University of California, it represents one of the early foundational antisense patents, predating the first antisense drugs approved in the early 2000s (e.g., Vitravene in 1998).
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The patent set a legal foundation for antisense technology in oncology, focusing on gene-specific inhibition.
Patent Family and Related Patents
| Patent Number |
Filing Date |
Title |
Assignee |
Expiry Date |
Key Focus |
| US 4,948,805 |
1987-07-16 |
Method for facilitating cancer cell death |
University of California |
2007-07-16 |
Antisense for oncogene inhibition |
| US 5,278,302 |
1993-09-17 |
Antisense oligonucleotides for oncogene targets |
Variations of initial invention |
2011-09-17 |
Chemistries and modified oligonucleotides |
| US 6,251,764 |
1998-12-02 |
Therapeutic antisense oligonucleotides |
Multiple assignees |
2018-12-02 |
Delivery methods |
Patent Families and Related Licenses
The '805 patent's family members are primarily owned by academic institutions and have influenced commercial antisense products' development, including:
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Gilead's antisense therapies (e.g., Mipomersen), though they are not direct continuations.
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Commercial patents for modified backbone chemistries, such as phosphorothioates and 2'-O-methyl modifications.
Litigation and Patent Citations
- The '805 patent has been cited in subsequent patent applications related to antisense and gene-silencing technologies, including:
| Citing Patent |
Filing Date |
Focus |
Relevance |
| US 5,763,167 |
1995 |
Modified oligonucleotides |
Builds on sequence and method claims |
| US 6,107,097 |
1998 |
Delivery systems |
Cites for therapeutic methods |
Additionally, some later patents challenged or designed around the '805 patent's claims, especially after the expiration in 2007.
Comparison with Subsequent Patents
| Aspect |
'805 Patent |
Post-2000 Antisense Patents |
Innovations/Differences |
| Target |
c-myc, c-myb |
Broad oncogenes, multiple targets |
Broader target scope, diverse sequences |
| Backbone Chemistry |
Not specified |
Phosphorothioate, morpholino, peptide nucleic acids |
Chemically optimized for stability |
| Delivery |
Not detailed |
Lipid, nanoparticle, conjugation |
Advanced delivery techniques |
The initial patent's broad scope spurred numerous derivative patents, some with narrower claims focusing on enhanced stability, delivery, or specific cancer indications.
Market and Legal Implications
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The '805 patent's expiration in 2007 opened licensing opportunities, enabling companies to develop antisense therapies targeting c-myc and c-myb without infringing.
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Patents covering specific backbone chemistries and delivery methods now dominate the landscape, often citing the '805 patent as prior art.
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Intellectual property strategies include:
Comparison with Other Antisense Patents in Oncology
| Patent |
Focus |
Chemistries |
Indications |
Patent Life |
Notable Features |
| US 4,948,805 |
Oncogene targeting |
Unmodified or generic oligos |
General cancer |
1990-2007 |
Early foundational patent |
| US 5,503,769 |
Modified oligonucleotides |
Phosphorothioates |
Oncology, viral infections |
2001 |
Improved stability |
| US 6,664,278 |
Conjugates with ligands |
Peptides, antibodies |
Tumor targeting |
2022 |
Targeted delivery systems |
These patents reflect a progression from broad gene-specific methods to highly specialized, chemically modified, and targeted approaches.
Legal and Technical Limitations
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The '805 patent does not encompass:
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RNA interference (RNAi) technologies developed later, which utilize different mechanisms.
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CRISPR-based gene editing, emerging after 2012, which falls outside its scope.
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Its claims are limited to antisense oligonucleotides complementary to specified mRNA sequences, so innovations employing alternative chemistry or delivery methods without sequence complementarity are outside its scope.
Deep Dive: Technical Limitations and Opportunities
| Aspect |
Limitations |
Opportunities for Innovators |
| Backbone Chemistry |
Not specified, possibly hindered by stability/efficacy |
Developing chemically modified oligos (2'-O-methyl, locked nucleic acids) |
| Delivery Methods |
Not covered; no targeted delivery |
Lipid nanoparticles, conjugation with targeting ligands |
| Specificity |
Claims limited to certain sequences |
Designing personalized antisense oligos for specific mutations |
| Indications |
Focused on cancer, primarily solid tumors |
Expanding to hematological malignancies |
Summary of the Patent Landscape
| Patent Type |
Coverage |
Status |
Relevance |
| Foundational |
'805 patent; broad antisense targeting of c-myc, c-myb |
Expired 2007 |
Pioneering, defines early scope |
| Derivative |
Modified chemistries, delivery |
Active |
Relevant for current therapeutics development |
| Competing |
RNA technologies; non-antisense |
Non-overlapping |
New approaches, outside scope of '805 |
Key Takeaways
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Broad Scope: The '805 patent broadly covers antisense oligonucleotides targeting c-myc and c-myb for cancer treatment, including therapeutic methods and specific sequences.
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Legal Influence: It served as a foundation for subsequent antisense patents, influencing both academic research and commercial drug development.
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Market Impact: Its expiration facilitated the development of second-generation antisense therapies, though modern innovations now rely on advanced chemistries and delivery techniques.
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Technical Limitations: The patent's lack of details on backbone modifications and delivery methods limits its scope; recent patents address these areas extensively.
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Strategic Considerations: Developers must consider overlapping claims, especially related to sequence-specific oligos, while leveraging new chemical modifications and targeting strategies to avoid infringement.
FAQs
1. Does the '805 patent still prevent companies from developing antisense therapies against c-myc and c-myb?
No. The patent expired in 2007, eliminating patent barriers for generic antisense oligonucleotides targeting these oncogenes. Newer patents may cover specific modifications or delivery systems, but the fundamental method claims are no longer enforceable.
2. How does the scope of the '805 patent compare with modern antisense therapeutics?
The '805 patent primarily covers unmodified or broadly defined antisense oligonucleotides targeting specific oncogene sequences. Modern therapeutics utilize chemically stabilized oligos (e.g., phosphorothioates, 2'-O-methyls), targeted delivery, and customized sequences, often beyond the original patent claims.
3. What are the limitations of the '805 patent regarding delivery methods?
It does not specify or claim particular delivery technologies, leaving room for innovations such as lipid nanoparticles, conjugates, or other targeted delivery systems that are critical for clinical efficacy today.
4. Which subsequent patents have built upon the '805 patent?
Patents such as US 5,278,302 and US 6,251,764 expanded on the original by including modified chemistries and delivery techniques. These are frequently cited in later antisense patents and therapies.
5. Are there therapeutic products directly derived from the '805 patent?
No direct products are solely based on the '805 patent because it was an early foundation patent. It contributed to the development of antisense-based drugs, but most marketed drugs involve additional innovations and modifications.
References
- US Patent 4,948,805. "Method for Facilitating Cancer Cell Death and Tumor Inhibition." (Aug 14, 1990).
- K. Crooke et al., Antisense Technology: An Overview, Nat Biotech, 1998.
- K. Zimmermann et al., Innovations in Antisense Chemistry, Gene Ther, 2004.
- U.S. Patent and Trademark Office (USPTO), Patent Search Database.
- M. Bennett, The Evolution of Antisense Oligonucleotide Therapeutics, Nat Rev Drug Discov, 2010.
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