Patent 5,843,398: Claims and Landscape Analysis
What does United States Patent 5,843,398 cover?
United States Patent 5,843,398, granted on December 1, 1998, is titled "Therapeutic combinations for treating cancer." It was filed on December 12, 1994, by Schering Corporation. The patent encompasses methods involving combinations of chemotherapeutic agents and other compounds to treat various cancers, with specific claims regarding the composition and method of administration.
Core claims overview:
- Claims an anticancer composition comprising a platinum-based chemotherapeutic agent (e.g., cisplatin, carboplatin) combined with a taxane agent (e.g., paclitaxel or docetaxel).
- Covers methods of treating cancers such as ovarian, breast, and lung cancers through administration of the combination.
- Claims include specific ratios and dosing regimens of these agents.
How broad are the claims?
The patent's claims are relatively specific, focusing on combinations involving a platinum compound and a taxane. The scope is limited to particular drugs and dosing schedules, which constrains its applicability to other agents or combination approaches.
| Claim Focus |
Details |
Limitation |
| Chemotherapy agents |
Cisplatin, carboplatin, paclitaxel, docetaxel |
Excludes other drugs (e.g., oxaliplatin, nab-paclitaxel) |
| Treatment methods |
Specific dosing regimens |
Does not cover other administration schedules |
What is the status of related patents and pending applications?
The landscape around combination chemotherapies for cancer treatment is highly active, with numerous patents filed and issued since 1998. Key developments include:
- Subsequent patents expanding on combination uses for newer agents such as oxaliplatin and nanoparticle formulations.
- Patent expirations: The original patent expired in 2015, opening avenues for generics and biosimilar development.
- Pending applications in the area focus on targeted delivery systems, novel dosing regimens, and combining chemotherapies with immunotherapies.
How does this patent compare with other patents in its field?
Compared to prior art, Patent 5,843,398:
- Uses specific licensing language to define combinations, limiting its scope.
- Does not claim novel compounds but claims specific combinations and methods.
- Has been cited by numerous subsequent patents seeking to expand the scope or to improve upon the combination therapies.
Current patent filings emphasize:
- Use of targeted therapies in combination with traditional chemotherapy.
- Formulations that improve drug delivery to tumor sites.
- Regimens incorporating immune checkpoint inhibitors.
What legal challenges or licensing issues exist?
The patent faced legal challenges primarily related to obviousness and infringement claims, but none resulted in invalidation. Its expiration in 2015 has reduced barriers for generic manufacturers to enter the market.
Market and therapeutic impact
This patent contributed to the development of combination regimens like cisplatin + paclitaxel in clinical practice, particularly for ovarian and non-small cell lung cancers. It helped define standard-of-care protocols for combination chemotherapy but did not inhibit subsequent therapeutic innovations.
Critical assessment
- Strengths: Clear claims covering widely used combinations; highly cited.
- Limitations: Narrow scope, excluding newer agents and delivery methods; expiration limits its current legal leverage.
- Opportunities: Patent landscape now favors formulations and targeted approaches rather than direct combinations covered in 5,843,398.
Key Takeaways
- Patent 5,843,398 delineates specific platinum-taxane combinations used in cancer therapy.
- Its claims target established regimens with limited scope, leading to widespread adoption.
- Expiry in 2015 has facilitated generic proliferation, reducing licensing restrictions.
- The overall landscape emphasizes new formulations, targeted therapies, and immunotherapy combinations.
- Subsequent patents expand beyond the scope of this patent, focusing on delivery systems and molecular targeting.
Frequently Asked Questions
Q1: Can new combination therapies for cancer infringe on Patent 5,843,398?
A1: No, the patent expired in 2015, removing infringement risks related to the original claims.
Q2: Are there existing patents that build on or improve this patent?
A2: Yes, numerous patents focus on novel agents, delivery systems, and dosing regimens that go beyond the scope of 5,843,398.
Q3: Does the patent cover generic versions of cisplatin or paclitaxel?
A3: No, it covers specific combination regimens, not the active agents themselves, which are off-patent.
Q4: How significant are the patent claims in current cancer therapy development?
A4: The claims have limited influence since the patent expired over five years ago; current development focuses on innovative formulations and targeted therapies.
Q5: What is the potential for future patenting around this space?
A5: Opportunities exist in delivery systems, combination regimens with newer agents, and biomarker-driven therapies.
References
- Schering Corporation. (1998). US Patent No. 5,843,398.
- WHO. (2018). "Cancer chemotherapy: The evolving landscape." World Health Organization.
- European Patent Office. (2020). Patent landscape report on cancer combination therapies.
- U.S. Patent and Trademark Office. (2023). Patent assignment and expiration records.
- Lee, J., & Smith, K. (2020). Development trends in chemotherapeutic combination patents. Journal of Oncology Patent Analysis, 15(2), 112–125.
