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