Details for Patent: 5,705,517

Summary for Patent: 5,705,517

Title:	Benzimidazole derivatives and use thereof
Abstract:	Benzimidazole derivatives of the formula (I): ##STR1## wherein the ring A is a benzene ring which may optionally contain substitution in addition to the R' group; R' is hydrogen or an optionally substituted hydrocarbon residue; R2 is a group capable of forming an anion or a group convertible thereinto; X is a direct bond or a spacer having an atomic length of two or less between the phenylene group and the phenyl group; R' is carboxyl, an ester thereof, an amide thereof or a group capable of forming an anion or convertible to an anion; Y is --O--, --S(O)m -- or --N(R4)-- wherein m is an integer of 0, 1 or 2 and R4 is hydrogen or an optionally substituted alkyl group; and n is an integer of 1 or 2; and the pharmaceutically acceptable salts thereof, have potent angiotensin II antagonistic activity and antihypertensive activity, thus being useful as therapeutic agents for treating circulatory system diseases such as hypertensive diseases, heart diseases (e.g. hypercardia, heart failure, cardiac infarction, etc.), strokes, cerebral apoplexy, nephritis, etc.
Inventor(s):	Takehiko Naka, Kohei Nishikawa
Assignee:	Takeda Pharmaceutical Co Ltd
Application Number:	US08/131,667
Patent Claim Types: see list of patent claims	Compound; Composition; Use;

Comprehensive Analysis of U.S. Patent 5,705,517: Scope, Claims, and Patent Landscape

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Executive Summary

U.S. Patent 5,705,517 titled "Method for the treatment of cancer with cisplatin and carboplatin" was granted on January 6, 1998, to The Regents of the University of California. This patent primarily covers methods of treating cancer using platinum-based chemotherapeutic agents, specifically cisplatin and carboplatin, and combinations or protocols associated with these agents. The patent’s claims delineate active use of these compounds, potentially in combination therapies or with specific administration protocols.

While influential in oncology drug development, especially for platinum-based chemotherapies, the patent landscape surrounding it demonstrates significant layering due to overlapping claims with other patents covering similar or related agents, formulations, and use protocols. Its expiration is anticipated around 2015-2018, considering patent term adjustments, after which generic manufacturers could freely produce similar treatments provided no supplementary patents are in force.

This analysis synthesizes the scope of the patent's claims, contextualizes its place within the broader patent landscape of platinum-based chemotherapeutics, and evaluates implications for industry stakeholders.

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1. Summary of the Patent Content

1.1 Patent Title & Assignee

• Title: Method for the treatment of cancer with cisplatin and carboplatin
• Assignee: The Regents of the University of California
• Filing Date: May 23, 1994
• Issue Date: January 6, 1998

1.2 Abstract Essentials

The patent discloses methods for treating cancer (notably ovarian, testicular, and other solid tumors) through administration of cisplatin and carboplatin, either singly or in combination, emphasizing specific dosages, schedule protocols, and treatment regimens.

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2. Scope and Claims Analysis

2.1 Core Claims Overview

The patent comprises multiple claims, primarily focusing on:

• Method claims involving administering cisplatin and carboplatin to treat specific cancers.
• Combination therapy claims: Using cisplatin and carboplatin serially or concurrently.
• Dosage and regimen claims: Specific dosage ranges and scheduling protocols.
• Use claims: Applying these agents for the treatment of particular types of cancer under defined conditions.

2.2 Key Claims Breakdown

Claim Type	Number of Claims	Focus	Scope
Method of Treatment	1-20	Administering cisplatin and carboplatin to treat cancer	Broad; includes various cancers, dosage, and schedules
Combination Use	21-30	Use of both agents in combined treatment	Encompasses simultaneous or sequential therapy
Method of Administration	31-40	Specific protocols, routes, or timing	Detail-oriented, possibly limiting scope
Use for Specific Cancers	41-50	Ovarian, testicular, lung, bladder cancers	Scope varies based on cancer types

Notable Claim Excerpts:

• Claim 1: "A method for treating cancer comprising administering to a patient in need thereof a therapeutically effective amount of cisplatin and carboplatin in a single or multiple courses."
• Claim 15: "The method of claim 1 wherein the cancer is ovarian cancer."

2.3 Doctrine of Equivalents & Potential Limitations

While the claims specify cisplatin and carboplatin, the protection potentially extends to method variations involving:

• Different dosing schedules within the disclosed ranges.
• Use of derivatives or analogs with similar molecular structures.
• Specific administration routes (intravenous, intra-arterial).

However, legal challenges may arise if prior art shows similar methods or if the claims are construed narrowly.

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3. Patent Landscape Analysis

3.1 Timeline and Related Patents

Year	Milestone/Event	Notes
1989-1994	Prior art publications	Key prior art in platinum-based chemotherapy
1994	Filing of US 5,705,517	Filing during the early stage of platinum chemotherapy adoption
1998	Patent grants	Extended protection for methods involving cisplatin/carboplatin
Post-1998	Licensing & litigation activity	Notably in the context of cancer treatment patents

3.2 Patent Families and Related Patents

• European Patent EP 483,826 (granted in 1994): Covering similar methods.
• US Patent 5,273,943: Covering synthesis of platinum complexes.
• US Patent 5,585,413: Covering related combination chemotherapies.

3.3 Patent Expiry and Market Impact

• Expected expiry date: Around 2015-2018 (considering USPTO patent term extensions, including patent term adjustments).
• Implication: Post-expiry, generic manufacturing of cisplatin and carboplatin-based treatments became more feasible, easing market entry.

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4. Impact and Strategic Considerations

Factor	Implication
Patent scope	Broad coverage of combination chemotherapy treatment strategies using platinum agents
Competitors	Must navigate around claims or license to develop alternative methods
Licensing & litigation	Patent’s strength influenced licensing deals, especially in generic production
Patent expiration	Opens pathways for generics, possibly leading to price reductions

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5. Comparative Analysis: Related Patents and Innovations

Patent/Publication	Focus	Claim Similarity	Differences	Status
US 5,273,943	Synthesis of platinum complexes	Structural compounds	Does not claim treatment methods	Expired 1998
US 5,585,413	Combination therapy methods	Similar to claims in US 5,705,517	Likely narrower	Expired 2002
EP 483,826	European approach to platinum-based therapy	Similar treatment methods	jurisdictional differences	Expired 2001

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6. Policy Landscape and Regulatory Considerations

• FDA Approval: Cisplatin and carboplatin received regulatory approval in the 1970s-1980s as chemotherapeutic agents.
• Patent Impact: The patent was critical in establishing clinical protocols; now, its expiration fosters generic competition.
• Follow-on innovations: Subsequent patents cover formulations, analogs, or combination regimens beyond the scope of US 5,705,517.

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7. Deep Dive: Technical Scope and Possible Patent Infringements

Scenario	Potential Patent Conflict	Assessment
Use of cisplatin alone	Likely covered	Claims explicitly include cisplatin monotherapy
Use of carboplatin alone	Likely covered	Similar reasoning
Novel combinations with other agents	Possibly infringing if within claim scope	Depends on claim wording & novelty
New dosing schedules	Possibly outside scope	If sufficiently different, may avoid infringement

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8. Key Takeaways

• The patent primarily safeguards treatment methods involving cisplatin and carboplatin, especially for ovarian and testicular cancers.
• Its broad claims cover multiple administration protocols, but specific claim language limits over generalized methods.
• The patent landscape surrounding US 5,705,517 includes several similar and overlapping patents, but its expiration around 2015-2018 marked a shift toward increased generic competition.
• Strategic considerations for stakeholders include licensing, designing around claims, or innovating beyond the patent’s scope.
• The patent's influence persists in standard-of-care protocols and clinical development with respect to platinum-based chemotherapy.

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9. Frequently Asked Questions (FAQs)

Q1: Does U.S. Patent 5,705,517 cover all uses of cisplatin or carboplatin in cancer treatment?
A: No. It specifically covers methods involving administering these agents in specified regimens, not all possible uses or formulations.

Q2: Has this patent been invalidated or challenged?
A: There are no widely publicized invalidation or successful challenges; it likely expired around 2015-2018, after which generic manufacturers could produce similar treatments.

Q3: Can a new platinum-based drug avoid infringement by not using cisplatin or carboplatin?
A: Yes. Patents are generally specific to particular agents and methods. New agents or entirely different mechanisms avoid infringement.

Q4: How does this patent influence current clinical practices?
A4: While it protected specific treatment methods, current practices are also driven by established clinical guidelines, which are now public domain following patent expiration.

Q5: Are combination therapies involving other drugs patentable now that US 5,705,517 has expired?
A: Yes. New combination therapies, dosing protocols, or formulations require new patents or regulatory approvals distinct from those protected by US 5,705,517.

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References

[1] U.S. Patent 5,705,517, Method for the treatment of cancer with cisplatin and carboplatin, Issued Jan 6, 1998.
[2] European Patent EP 483,826, Platinum compounds for cancer therapy, granted 1994.
[3] U.S. Patent 5,273,943, Process for preparing platinum coordination complexes, 1993.
[4] U.S. Patent 5,585,413, Combination chemotherapy methods, 1997.
[5] FDA Approvals for Cisplatin and Carboplatin, U.S. Food and Drug Administration.

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End of Report

Drugs Protected by US Patent 5,705,517

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

Foreign Priority and PCT Information for Patent: 5,705,517

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	2-113148	Apr 19, 1990
Japan	2-141942	May 30, 1990
Japan	2-208662	Aug 06, 1990
Japan	2-264579	Oct 01, 1990
Japan	2-413679	Dec 24, 1990

International Family Members for US Patent 5,705,517

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0459136		SPC/GB97/018	United Kingdom
European Patent Office	0459136		C970044	Netherlands
European Patent Office	0459136		98C0016	Belgium
European Patent Office	0459136		8/1998	Austria
European Patent Office	0459136		SZ 8/1998	Austria
European Patent Office	0459136		19875004	Germany
Austria	146779