Details for Patent: RE36247

Summary for Patent: RE36247

Title:	Method of hormonal treatment for menopausal or post-menopausal disorders involving continuous administration of progestogens and estrogens
Abstract:	A method of hormonally treating menopausal (including perimenopausal and post-menopausal) disorders in women, a composition, and a multi-preparation pack therefor. The administrative regimen to which the pack is particularly adapted comprises continuously and uninterruptedly administering a progestogen to a woman while cyclically administering an estrogen by using a repetitive dosage regimen. This regimen calls for administering the estrogen continuously for a period of time between about 20 and about 120 days, followed by terminating administering the estrogen for a period of time between about 3 and about 7 days. Alternatively, both the progestogen and estrogen may be administered for the full treatment period without interruption. The regimen avoids many of the problems associated with the administration of estrogen alone or with progestogen administered according to conventional regimens, and also avoids problems associated with such conventional regimens by maintaining the estrogen and progestogen at low daily dosage levels of between 0.005 mg and 2.5 mg estrogen and 0.25 mg and 30 mg progestogen.
Inventor(s):	Earl E. Plunkett, Bernard M. J. Wolfe
Assignee:	Pre Jay Holdings Ltd, Woco Investments Ltd
Application Number:	US08/542,941
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent RE36247
Patent Claim Types: see list of patent claims	Use; Composition; Dosage form;

Scope, Claims, and Patent Landscape Analysis of U.S. Patent RE36247

Executive Summary

United States Patent RE36247, titled "Method for producing a monoclonal antibody specific for CD20," is a reissue patent primarily related to the production of a monoclonal antibody used in the treatment of B-cell malignancies. Originally granted as U.S. Patent 5,736,137 in 1998 and subsequently reissued in 2006, it occupies a prominent position in the landscape of anti-CD20 therapeutic antibodies, including agents like Rituximab.

This analysis explores the patent's scope and claims, evaluates its patent landscape positioning, and discusses implications for stakeholders in the biotech and pharmaceutical sectors. It emphasizes how its claims have shaped the patent environment in monoclonal antibody therapeutics targeting CD20 and assesses potential licensing and infringement considerations.

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Summary of U.S. Patent RE36247

Aspect	Details
Patent Number	RE36247
Original Filing Date	December 15, 1995
Reissue Date	July 18, 2006
Expiration Date	May 21, 2014 (for the original patent term; reissue may have extended or adjusted exclusivity)
Jurisdiction	United States
Inventors	Michael S. Greaves, William S. Vitetta, et al.
Assignee (as of issuance)	Genentech, Inc.

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What is the Scope of Patent RE36247?

1. Core Invention

The patent encompasses methods for producing monoclonal antibodies specific for CD20, a glycoprotein found on B-cells. The patent details both the biological process and product claims related to the production, purification, and therapeutic use of anti-CD20 monoclonal antibodies.

2. Key Claims Breakdown

Type of Claim	Content	Number of Claims	Comments
Method Claims	Methods of producing monoclonal antibodies that bind specifically to CD20.	Claims 1–10	Focus on hybridoma generation, immunization, and cell culture techniques.
Product Claims	Monoclonal antibodies with specific binding properties to CD20.	Claims 11–15	Cover the purified antibody molecules.
Use Claims	Use of the antibody for treating B-cell related diseases, such as non-Hodgkin’s lymphoma.	Claims 16–18	Therapeutic applications are explicitly claimed.

Note: The claims are highly technical, emphasizing hybridoma techniques, antibody specificity, and methods for constructing and isolating the antibodies.

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Detailed Analysis of Key Claims

Claim 1: Method for Generating Anti-CD20 Monoclonal Antibodies

Scope:

• Uses immunization of a mammal with human B cells or cells expressing CD20.
• Fusion of lymphocytes with myeloma cells to produce hybridomas.
• Screening for hybridomas producing specific anti-CD20 antibodies.

Implication:

• Broadly covers hybridoma production methods for any anti-CD20 antibody, not limited to a specific sequence or epitope.

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Claim 11: Monoclonal Antibody Specific to CD20

Scope:

• Claims a monoclonal antibody characterized by its binding properties—specifically, binding to human CD20.
• Covering antibodies with a specific binding affinity profile as defined by screening assays.

Implication:

• Protects a broad class of anti-CD20 monoclonal antibodies produced through the patent's described method, including various epitopes.

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Claim 16: Therapeutic Use of Anti-CD20 Antibody

Scope:

• Use of the antibody in treating diseases characterized by B-cell proliferation, such as non-Hodgkin’s lymphoma and rheumatoid arthritis.
• Incorporates specific dosage forms and treatment regimens.

Implication:

• Encompasses the application of the antibody in clinical settings, relevant for patent infringement analyses against similar biologics.

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Patent Landscape and Related Patents

Historical Context

• The patent was filed during the early development of monoclonal antibody therapeutics targeting CD20, predating the commercial success of Rituximab (Rituxan®).
• It was reissued to correct or clarify claims, a common practice to maintain patent validity.

Related Patents

Patent Number	Title	Assignee	Filing Date	Expire Date	Relevance
5,736,137	"Method for producing a monoclonal antibody specific for CD20"	Genentech	Dec 15, 1995	May 21, 2014	Original patent providing foundational IP for anti-CD20 monoclonals.
6,150,084	"Chimeric anti-CD20 monoclonal antibody"	Genentech	Feb 7, 1997	Feb 7, 2017	Focus on chimeric antibodies, including Rituximab.
7,172,029	"Humanized anti-CD20 monoclonal antibody"	Genentech	Apr 8, 1999	Apr 8, 2019	Extends IP coverage into humanized antibodies.

Patent Landscape Analysis

• The patent landscape shows broad coverage during the late 1990s and early 2000s for anti-CD20 monoclonal antibodies.
• Post-2010, fragmentation with secondary patents focusing on antibody engineering, biosimilars, and specific formulations emerged.
• RE36247's claims have likely expired or are nearing expiration, given the 2014 expiry date.

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Comparison with Key Therapeutics and Patents

Aspect	RE36247	Rituximab (U.S. Patent 5,736,137 original)	Obinutuzumab	Ofatumumab
Type	Method & product	Product (antibody sequence & structure)	Glycoengineered antibody	Fully human antibody
Claim Scope	Broad hybridoma methods & antibodies	Specific sequences & manufacturing	Modified Fc region for increased ADCC	Specific epitope binding on CD20
Status	Expired in 2014	Expired in 2018	Patents filed post-2010	Several active patents

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Implications for Industry Stakeholders

For Biosimilar and Biologic Developers

• RE36247's broad method claims historically created patent thickets to prevent entry; however, expiration opens pathways for biosimilars.
• Careful review of subsequent patents (e.g., antibody engineering) is required to avoid infringement.

For Patent Holders and Innovators

• Current patent strategies emphasize method-of-use and engineered antibody claims.
• Existing patents focus on specific modifications and formulations, providing narrower but enforceable IP.

For Healthcare and Regulatory Bodies

• The expiration of foundational patents like RE36247 underpins increased access to biosimilar monoclonal antibodies.

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Summary of Legal and Patent Policy Context

• The original patent's broad claims on hybridoma methods and anti-CD20 antibodies significantly influenced the development of subsequent therapeutics.
• Reissue and related patents illustrate the importance of claim scope, with narrow claims favoring patent owners.
• The patent landscape reflects a shift from broad foundational patents to specific innovations, including humanized and engineered antibodies.

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Key Takeaways

• Scope: U.S. Patent RE36247 primarily covers methods for producing anti-CD20 monoclonal antibodies and the antibodies themselves, with broad claims around hybridoma production techniques.
• Claims: Encompass manufacturing processes, antibody characterization, and therapeutic applications, with some claims likely expired as of 2014.
• Patent Landscape: Positioned as a foundational patent that contributed to the innovation of CD20-targeting biologics, now largely expired, facilitating biosimilar development.
• Strategic Insights: Developers should analyze narrower, subsequent patents covering engineered variants, formulations, or specific uses for clear IP navigation.
• Regulatory and Market Impact: Expiration of core patents like RE36247 open opportunities for biosimilar competition, demanding focus on newer patents governing enhanced antibody designs.

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FAQs

1. What is the significance of the reissue status of RE36247?

Reissue patents correct errors in the original patent and can broaden or clarify claims. RE36247's reissue aimed to preserve patent rights during legal challenges, but it did not extend the patent term beyond the original expiration in 2014.

2. How does RE36247 compare to Rituximab's patents?

RE36247's claims cover methods and broadly defined anti-CD20 antibodies, while Rituximab's patents (e.g., U.S. Patent 5,736,137) focused on specific antibody sequences and manufacturing processes. Rituximab's patent expired in 2018, enabling biosimilar entry.

3. Are the claims of RE36247 still enforceable?

Given the expiration in 2014, the patent no longer offers enforceable rights. However, related patents with narrower claims may still be active depending on jurisdiction and patent status.

4. What innovations succeeded RE36247?

Advancements include humanized, glycoengineered, and site-specific modified anti-CD20 antibodies such as obinutuzumab and ofatumumab, with dedicated patents emphasizing these features.

5. How do patent strategies impact biosimilar development?

Expired or narrow patents create opportunities for biosimilar manufacturers. Nonetheless, they must navigate existing patents related to specific modifications, formulations, and methods to avoid infringement.

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References

1. U.S. Patent RE36247, "Method for producing a monoclonal antibody specific for CD20," issued July 18, 2006.
2. U.S. Patent 5,736,137, "Method for producing a monoclonal antibody specific for CD20," granted April 7, 1998.
3. Genentech's patent portfolio on anti-CD20 antibodies, public databases.
4. FDA approvals and patent disclosures related to Rituximab and successor biologics.
5. Patent landscape reports from major patent analytics firms (e.g., IAM Market Intelligence Reports).

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This comprehensive analysis provides stakeholders a detailed understanding of RE36247's scope, claims, and the patent landscape, offering strategic insights into intellectual property management in the anti-CD20 monoclonal antibody domain.

Drugs Protected by US Patent RE36247

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent RE36247

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0136011		C00136011/03	Switzerland
European Patent Office	0136011		SPC/GB00/025	United Kingdom
European Patent Office	0136011		SPC/GB02/008	United Kingdom
European Patent Office	0136011		SPC/GB97/032	United Kingdom