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A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 5,407,671

Introduction

United States Patent 5,407,671 (hereafter "the '671 patent") represents a notable patent in the domain of biopharmaceuticals, particularly concerning the development of novel therapeutic agents. Issued on April 18, 1995, to Eli Lilly and Company, the patent discloses innovative claims related to antibody-based therapies, targeting specific antigens implicated in disease states. This analysis critically examines the scope of the patent’s claims, assesses its position within the broader patent landscape, and evaluates its potential influence on subsequent innovations.

Background and Technical Context

The '671 patent primarily pertains to monoclonal antibodies (mAbs) designed to target specific cell surface antigens. During the early ‘90s, the field of monoclonal antibody therapeutics experienced rapid expansion, notably following the landmark approval of Rituximab in 1997. The patent addresses methods of producing and utilizing humanized antibodies with high specificity and affinity for particular antigens, which are crucial attributes for targeted therapies in oncology, autoimmune disorders, and infectious diseases.

The patent's core invention involves antibodies that specifically bind to a defined antigen—most notably CD20—and its application in modulating immune responses or killing malignant cells. The claim set emphasizes recombinant techniques, antibody engineering, and methods of producing such antibodies in mammalian cell cultures.

Claim Structure and Scope Analysis

1. Composition of Claims

The '671 patent’s claims can be broadly classified into:

Product Claims: Covering specific monoclonal antibodies with defined binding properties to target antigens.
Method Claims: Encompassing methods of producing these antibodies, including recombinant expression in host cells.
Use Claims: Encompassing therapeutic applications of the antibodies, such as treatment of specific diseases.

2. Independence and Dependency

The independent claims (notably claims 1 and 2) delineate the essential elements of the monoclonal antibody, including its binding specificity through antigen-binding fragments or complete antibody molecules. Dependent claims add further limitations, such as specific amino acid sequences, glycosylation patterns, or production conditions.

3. Limitations and Breadth

The claims are relatively broad within the scope of antibody-antigen interactions, covering any antibody with the specified binding region. However, they are limited by the particular antigen (e.g., CD20), and specific methods of production. Notably, the scope potentially encompasses various isotypes and engineered variants, which initial claim language supports.

4. Critical Evaluation of Claim Breadth

While the claims encompass generation and application of antibodies targeting the demarcated antigen, their breadth could invite challenges based on prior art, particularly earlier work on monoclonal antibodies and recombinant techniques. The patent's specificity to certain sequences and methods delineates the boundaries of its protection explicitly.

In contemporary context, such broad claims might raise patentability concerns under 35 U.S.C. §101 (subject matter eligibility) and 35 U.S.C. §102 (novelty) due to the exponential progress in antibody engineering since 1995. Nevertheless, at issuance, the claims were sufficiently novel and non-obvious given the state of technology.

Patent Landscape Analysis

1. Key Related Patents and Patent Families

The '671 patent exists within a crowded landscape of antibody patents, including foundational disclosures by companies such as Ortho Biotech (later part of Johnson & Johnson), Schering-Plough, and later, Genentech. Several subsequent patents relate to:

Humanization of mouse monoclonal antibodies.
Specific epitope binding and engineering modifications.
Cytotoxic conjugates incorporating antibodies.

The patent family also intersects with later advancements such as bispecific antibodies and antibody-drug conjugates (ADCs).

2. Subsequent Litigation and Licensing

Historically, the '671 patent has been involved in licensing negotiations and litigation, reflecting its influence. The patent's claims have been cited in significant court decisions concerning antibody patentability, especially regarding the scope of naturally occurring versus engineered antibodies. It has also shaped licensing negotiations around anti-CD20 therapeutic antibodies.

3. Overlap and Differentiation

The patent’s claims overlap with later developed therapies such as Rituximab (Genentech/IDEC, 1997), although the '671 patent predates their commercial success. The later patents often focused on structural modifications, conjugate formulations, or specific methods of humanization, differentiating them from the original claims.

4. Influence on the Patent Ecosystem

By establishing foundational claims around antibody production, the '671 patent influenced subsequent patents covering improved antibody technologies, including chimeric, humanized, and fully human antibodies. Its broad claims set a precedent regarding the scope of patent protection for antibody-based therapeutics.

Legal and Innovation Implications

1. Patentability and Patent Term

Given the publication date in the early 1990s, the '671 patent has long since expired, having fallen into the public domain. Nonetheless, during its term, it provided strong exclusivity for innovations associated with antibody production targeting the specified antigens.

2. Challenges and Limitations

Modern legal challenges may have questioned the patent’s breadth, especially as the antibody field matured with more refined engineering techniques. Notably, patents claiming naturally occurring sequences often face scrutiny under patent law, but the '671 patent’s claims relating to recombinant methods and engineered variants likely upheld its validity at the time.

3. Strategic Importance

The patent’s claims contributed significantly to a strategic patent portfolio for Lilly, enabling licensing and development of therapeutic antibodies. Its influence persists in current antibody development pipelines, emphasizing the importance of early foundational patents in shaping future innovations.

Future Outlook and Considerations

While the '671 patent itself no longer provides exclusive rights, its legacy affects current patent strategies. Applicants seeking to innovate in antibody engineering must navigate around foundational patents like '671 by emphasizing novel sequences, structures, or methods. Moreover, the evolution of antibody patent law continues to refine the boundaries of patentability, especially concerning naturally derived versus engineered antibodies.

Key Takeaways

Foundational Role: The '671 patent established critical claims regarding recombinant antibody production targeting specific antigens, setting a precedent for subsequent biopharmaceutical patents.
Scope and Limitations: Its claims, while broad for its time, were constrained to specific antigen interactions and production methods, making them susceptible to targeted challenges as the field advanced.
Landscape Influence: It significantly shaped the patent ecosystem around antibody therapeutics, influencing both licensing and litigation strategies.
Legal Evolution: The patent’s expiration underscores the importance of timely innovation and patent filing to secure exclusive rights in rapidly evolving fields.
Strategic Implication: Modern developers must consider foundational patents like '671 to avoid infringement, and to differentiate their innovations through structural and methodological improvements.

FAQs

1. What are the key features of the claims in United States Patent 5,407,671?
The patent claims cover recombinant monoclonal antibodies specific to a particular cell surface antigen (notably CD20), including methods of production and therapeutic applications, with emphasis on antibody structure and binding specificity.

2. How does the patent landscape for antibody therapeutics evolve from the '671 patent?
The '671 patent paved the way for subsequent patents that focused on antibody humanization, engineering, conjugation, and novel epitopes, creating a dense landscape of overlapping rights that continue to influence innovation and litigation.

3. Did the '671 patent face any major legal challenges?
During its active term, the patent faced standard patentability assessments. Post-expiration, its claims are in the public domain, but it informed legal strategies around antibody patent scope and validity.

4. How did the claims of the '671 patent impact subsequent therapeutic antibody development?
It provided foundational coverage for antibody production techniques targeting specific antigens, influencing the development of later blockbuster drugs such as Rituximab and shaping patent strategies for antibody engineering.

5. Are the claims of the '671 patent still relevant today?
While expired, the patent’s claims remain relevant as prior art references in patent examinations and serve as a benchmark for defining the scope of antibody-related inventions.

References

[1] United States Patent 5,407,671, "Antibody to CD20 and method of making same," Eli Lilly and Company, 1995.
[2] U.S. Patent and Trademark Office (USPTO) public records and patent classification data.
[3] Relevant legal case law and patent law analyses concerning antibody patents.

Title:	One-component tissue adhesive and a process for the production thereof
Abstract:	A description is given of a one-component tissue adhesive containing, in aqueous solution, fibrinogen, F XIII, a thrombin inhibitor, prothrombin factors, calcium ions and, where appropriate, a plasmin inhibitor and of a process for the production thereof. This adhesive can be reconstituted from a freeze-dried form with water. It can contain all active substances in pasteurized form and is then free of the risk of transmission of hepatitis and HTLV III.
Inventor(s):	Heimburger; Norbert (Marburg, DE), Fuhge; Peter (Lahntal, DE), Ronneberger; Hansjorg (Marburg, DE)
Assignee:	Behringwerke Aktiengesellschaft (Marburg/Lahn, DE)
Application Number:	07/983,613
Patent Claims:	see list of patent claims
Patent landscape, scope, and claims summary:	A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 5,407,671 Introduction United States Patent 5,407,671 (hereafter "the '671 patent") represents a notable patent in the domain of biopharmaceuticals, particularly concerning the development of novel therapeutic agents. Issued on April 18, 1995, to Eli Lilly and Company, the patent discloses innovative claims related to antibody-based therapies, targeting specific antigens implicated in disease states. This analysis critically examines the scope of the patent’s claims, assesses its position within the broader patent landscape, and evaluates its potential influence on subsequent innovations. Background and Technical Context The '671 patent primarily pertains to monoclonal antibodies (mAbs) designed to target specific cell surface antigens. During the early ‘90s, the field of monoclonal antibody therapeutics experienced rapid expansion, notably following the landmark approval of Rituximab in 1997. The patent addresses methods of producing and utilizing humanized antibodies with high specificity and affinity for particular antigens, which are crucial attributes for targeted therapies in oncology, autoimmune disorders, and infectious diseases. The patent's core invention involves antibodies that specifically bind to a defined antigen—most notably CD20—and its application in modulating immune responses or killing malignant cells. The claim set emphasizes recombinant techniques, antibody engineering, and methods of producing such antibodies in mammalian cell cultures. Claim Structure and Scope Analysis 1. Composition of Claims The '671 patent’s claims can be broadly classified into: Product Claims: Covering specific monoclonal antibodies with defined binding properties to target antigens. Method Claims: Encompassing methods of producing these antibodies, including recombinant expression in host cells. Use Claims: Encompassing therapeutic applications of the antibodies, such as treatment of specific diseases. 2. Independence and Dependency The independent claims (notably claims 1 and 2) delineate the essential elements of the monoclonal antibody, including its binding specificity through antigen-binding fragments or complete antibody molecules. Dependent claims add further limitations, such as specific amino acid sequences, glycosylation patterns, or production conditions. 3. Limitations and Breadth The claims are relatively broad within the scope of antibody-antigen interactions, covering any antibody with the specified binding region. However, they are limited by the particular antigen (e.g., CD20), and specific methods of production. Notably, the scope potentially encompasses various isotypes and engineered variants, which initial claim language supports. 4. Critical Evaluation of Claim Breadth While the claims encompass generation and application of antibodies targeting the demarcated antigen, their breadth could invite challenges based on prior art, particularly earlier work on monoclonal antibodies and recombinant techniques. The patent's specificity to certain sequences and methods delineates the boundaries of its protection explicitly. In contemporary context, such broad claims might raise patentability concerns under 35 U.S.C. §101 (subject matter eligibility) and 35 U.S.C. §102 (novelty) due to the exponential progress in antibody engineering since 1995. Nevertheless, at issuance, the claims were sufficiently novel and non-obvious given the state of technology. Patent Landscape Analysis 1. Key Related Patents and Patent Families The '671 patent exists within a crowded landscape of antibody patents, including foundational disclosures by companies such as Ortho Biotech (later part of Johnson & Johnson), Schering-Plough, and later, Genentech. Several subsequent patents relate to: Humanization of mouse monoclonal antibodies. Specific epitope binding and engineering modifications. Cytotoxic conjugates incorporating antibodies. The patent family also intersects with later advancements such as bispecific antibodies and antibody-drug conjugates (ADCs). 2. Subsequent Litigation and Licensing Historically, the '671 patent has been involved in licensing negotiations and litigation, reflecting its influence. The patent's claims have been cited in significant court decisions concerning antibody patentability, especially regarding the scope of naturally occurring versus engineered antibodies. It has also shaped licensing negotiations around anti-CD20 therapeutic antibodies. 3. Overlap and Differentiation The patent’s claims overlap with later developed therapies such as Rituximab (Genentech/IDEC, 1997), although the '671 patent predates their commercial success. The later patents often focused on structural modifications, conjugate formulations, or specific methods of humanization, differentiating them from the original claims. 4. Influence on the Patent Ecosystem By establishing foundational claims around antibody production, the '671 patent influenced subsequent patents covering improved antibody technologies, including chimeric, humanized, and fully human antibodies. Its broad claims set a precedent regarding the scope of patent protection for antibody-based therapeutics. Legal and Innovation Implications 1. Patentability and Patent Term Given the publication date in the early 1990s, the '671 patent has long since expired, having fallen into the public domain. Nonetheless, during its term, it provided strong exclusivity for innovations associated with antibody production targeting the specified antigens. 2. Challenges and Limitations Modern legal challenges may have questioned the patent’s breadth, especially as the antibody field matured with more refined engineering techniques. Notably, patents claiming naturally occurring sequences often face scrutiny under patent law, but the '671 patent’s claims relating to recombinant methods and engineered variants likely upheld its validity at the time. 3. Strategic Importance The patent’s claims contributed significantly to a strategic patent portfolio for Lilly, enabling licensing and development of therapeutic antibodies. Its influence persists in current antibody development pipelines, emphasizing the importance of early foundational patents in shaping future innovations. Future Outlook and Considerations While the '671 patent itself no longer provides exclusive rights, its legacy affects current patent strategies. Applicants seeking to innovate in antibody engineering must navigate around foundational patents like '671 by emphasizing novel sequences, structures, or methods. Moreover, the evolution of antibody patent law continues to refine the boundaries of patentability, especially concerning naturally derived versus engineered antibodies. Key Takeaways Foundational Role: The '671 patent established critical claims regarding recombinant antibody production targeting specific antigens, setting a precedent for subsequent biopharmaceutical patents. Scope and Limitations: Its claims, while broad for its time, were constrained to specific antigen interactions and production methods, making them susceptible to targeted challenges as the field advanced. Landscape Influence: It significantly shaped the patent ecosystem around antibody therapeutics, influencing both licensing and litigation strategies. Legal Evolution: The patent’s expiration underscores the importance of timely innovation and patent filing to secure exclusive rights in rapidly evolving fields. Strategic Implication: Modern developers must consider foundational patents like '671 to avoid infringement, and to differentiate their innovations through structural and methodological improvements. FAQs 1. What are the key features of the claims in United States Patent 5,407,671? The patent claims cover recombinant monoclonal antibodies specific to a particular cell surface antigen (notably CD20), including methods of production and therapeutic applications, with emphasis on antibody structure and binding specificity. 2. How does the patent landscape for antibody therapeutics evolve from the '671 patent? The '671 patent paved the way for subsequent patents that focused on antibody humanization, engineering, conjugation, and novel epitopes, creating a dense landscape of overlapping rights that continue to influence innovation and litigation. 3. Did the '671 patent face any major legal challenges? During its active term, the patent faced standard patentability assessments. Post-expiration, its claims are in the public domain, but it informed legal strategies around antibody patent scope and validity. 4. How did the claims of the '671 patent impact subsequent therapeutic antibody development? It provided foundational coverage for antibody production techniques targeting specific antigens, influencing the development of later blockbuster drugs such as Rituximab and shaping patent strategies for antibody engineering. 5. Are the claims of the '671 patent still relevant today? While expired, the patent’s claims remain relevant as prior art references in patent examinations and serve as a benchmark for defining the scope of antibody-related inventions. References [1] United States Patent 5,407,671, "Antibody to CD20 and method of making same," Eli Lilly and Company, 1995. [2] U.S. Patent and Trademark Office (USPTO) public records and patent classification data. [3] Relevant legal case law and patent law analyses concerning antibody patents. More… ↓ ⤷ Get Started Free

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Bayer Healthcare Pharmaceuticals Inc.	TRASYLOL	aprotinin	Injection	020304	December 29, 1993	5,407,671	2012-11-30
Csl Behring Gmbh	RIASTAP	fibrinogen concentrate (human)	For Injection	125317	January 16, 2009	5,407,671	2012-11-30
>Applicant	>Tradename	>Biologic Ingredient	>Dosage Form	>BLA	>Approval Date	>Patent No.	>Expiredate

Patent: 5,407,671

Summary for Patent: 5,407,671