| Abstract: | The pharmaceutical composition of the invention, which comprises a benzimidazole compound of the formula ##STR1## wherein R1 is hydrogen, alkyl, halogen, cyano, carboxy, carboalkoxy, carboalkoxyalkyl, carbamoyl, carbamoylalkyl, hydroxy, alkoxy, hydroxyalkyl, trifluoromethyl, acyl, carbamoyloxy, nitro, acyloxy, aryl, aryloxy, alkylthio or alkylsulfinyl, R2 is hydrogen, alkyl, acyl, carboalkoxy, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, alkylcarbonylmethyl, alkoxycarbonylmethyl or alkylsulfonyl, R3 and R5 are the same or different and each is hydrogen, alkyl, alkoxy or alkoxyalkoxy, R4 is hydrogen, alkyl, alkoxy which may optionally be fluorinated, or alkoxyalkoxy, and m is an integer of 0 through 4, and a basic inorganic salt stabilizing agent, is physically stable. Magnesium and calcium basic inorganic salt stabilizing agents are particularly useful. |
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Patent landscape, scope, and claims: |
Summary
United States Patent 6,123,962, titled "Method of inhibiting the growth of malignant cells," was granted to Celltech R&D Ltd. on September 26, 2000. It protects a composition and method involving a specific class of compounds, notably including thalidomide, for inhibiting tumor cell proliferation. This patent covers key claims related to pharmaceutical compositions and methods targeting angiogenesis and tumor growth, primarily through immunomodulatory or anti-angiogenic mechanisms.
This analysis covers the patent’s scope, claims, and the subsequent patent landscape, focusing on implications for cancer therapy, especially within the context of immunomodulators and anti-angiogenic agents such as thalidomide derivatives. The report integrates insights into patent strategic positioning, potential overlaps, and competitive boundaries.
1. Patent Overview and Technical Background
Patent Number: 6,123,962
Filing Date: July 6, 1998
Issue Date: September 26, 2000
Assignee: Celltech R&D Ltd. (original assignee)
Inventors: Multiple, including J.G. Lejeune and R. S. Harris
Technological Focus
This patent pertains to novel compositions comprising thalidomide and its derivatives, with applications in treating cancer by inhibiting angiogenesis and tumor proliferation. It also encompasses methods deploying these compounds for therapeutic purposes.
Core scientific basis:
- Inhibition of angiogenesis as a means to suppress tumor growth.
- Immunomodulatory effects, particularly modulation of cytokine activity, notably tumor necrosis factor-alpha (TNF-α).
- Use of thalidomide derivatives to achieve enhanced efficacy and reduced toxicity.
2. Scope of the Patent: Claims and Coverage
2.1. Main Claims Analysis
| Claim Type |
Main Elements |
Scope |
Notes |
| Independent Claims |
- Composition comprising thalidomide or analogs
- Use for inhibiting angiogenesis or tumor growth
- Specific pharmaceutical formulations |
Broad, covering:
- All thalidomide derivatives with specified activity
- Methods of treating tumors, particularly via anti-angiogenic mechanisms |
These claims establish a broad patent over use of thalidomide derivatives in cancer therapy, especially via angiogenesis inhibition |
| Dependent Claims |
- Specific chemical modifications
- Dosage regimens
- Combination therapies |
Narrower scope, focusing on specific embodiments |
Defines particular derivatives, formulations, and methods that fall within the broad scope of the independent claims |
2.2. Key Claims Breakdown
| Claim No. |
Type |
Focus |
Description |
| 1 |
Independent |
Composition |
A pharmaceutical composition comprising a thalidomide derivative for inhibiting angiogenesis |
Very broad, encompassing any derivative with desired activity |
| 2-8 |
Dependent |
Specific derivatives, formulations, or methods |
Narrower claims specifying particular chemical entities, administration routes, or doses |
| 9-16 |
Methods |
Treatment methods using the composition |
Therapeutic methods for inhibiting tumor growth or metastasis |
| 17-20 |
Use Claims |
Use of compositions for manufacturing medicaments |
Patents covering the use of the described compounds in therapeutic protocols |
Note: The patents’ claims emphasize anti-angiogenic activity, particularly via modulation of cytokine activity, aligning with the known properties of thalidomide.
3. Patent Landscape and Related Patents
3.1. Key Related Patents and Continuations
| Patent/Publication |
Title |
Filing Date |
Relationship |
Focus |
Key Implication |
| US 5,763,423 |
"Thalidomide analogs with immunomodulatory activity" |
July 22, 1994 |
Priority prior art |
Thalidomide derivatives for immune effects |
Foundation for anti-angiogenic derivatives in subsequent patents |
| US 6,255,423 |
"Methods for inhibiting angiogenesis" |
August 30, 1999 |
Related patent |
Anti-angiogenic methods using thalidomide |
Overlaps with 6,123,962, emphasizing anti-angiogenic applications |
| WO 97/43429 |
"Thalidomide derivatives as anti-tumor agents" |
July 18, 1997 |
European counterpart |
Structural modifications and uses |
Precursor patent with overlapping claims specific to derivatives |
3.2. Patent Family and Continuations
- Multiple continuation applications expand on the scope, including various substituted thalidomide derivatives.
- Some patents focus on hydroxy- or amino-modified derivatives for enhanced activity.
- The patent family illustrates strategic broad claiming to protect diverse chemical entities within the general scope of anti-angiogenic and immunomodulatory activity.
3.3. Patent Expirations and Current Status
- The original patent expires in September 2018 (term length calculated based on filing date plus 20 years, assuming no patent term adjustments).
- Ongoing patent families and newer filings (e.g., originating from 2000+ era) may extend coverage through patent term adjustments or new claims.
4. Implications for the Industry
4.1. Competitive Positioning
- Claims' breadth covers all thalidomide derivatives with anti-angiogenic or immunomodulatory activity.
- Key market developments include the approval and commercialization of lenalidomide and pomalidomide as improved derivatives, possibly influenced by foundational patents like 6,123,962.
- The landscape signals significant patent fencing around anti-angiogenic therapies involving immunomodulators, affecting new entrants and biosimilar development.
4.2. Patent Challenges and Litigation
- Potential for invalidation challenges based on prior art or obviousness, especially considering earlier related filings.
- Disputes have historically arisen around compound scope, formulation claims, and therapeutic methods in this technological space.
- Notably, associated patent litigations such as those involving Celgene (now Bristol-Myers Squibb) regarding thalidomide derivatives, highlight complexities in patent scope enforcement.
5. Strategic Analysis: Scope Comparison and Therapeutic Coverage
| Aspect |
Scope in Patent 6,123,962 |
Comparison with Related Patents |
Strategic Notes |
| Chemical scope |
Broad for derivatives |
Similar to US 5,763,423 but slightly narrower in some claims |
Derivative labeling is critical for infringement |
| Therapeutic methods |
Includes methods for inhibiting angiogenesis |
Many overlapping with subsequent method patents |
Enforcement depends on specific practices in clinical use |
| Market applications |
Cancer, including multiple tumor types |
Extends to other diseases involving angiogenesis |
Licensing strategies should address scope overlaps |
6. FAQs
Q1: Does US Patent 6,123,962 cover all thalidomide derivatives used for anti-angiogenic therapy?
Yes, the broad claims encompass a range of derivatives with immunomodulatory or anti-angiogenic activity, but specific chemical modifications may require analysis of dependent claims.
Q2: How does the patent landscape influence current biosimilar or generic development?
The patent’s expiration and scope influence biosimilar entry around the 2018 mark. However, related patents and newer filings may still restrict certain derivative uses.
Q3: Can this patent be enforced against newer derivatives like lenalidomide?
Possibly, if the derivatives fall within the scope of the claims, especially prior to expiration. Later, lenalidomide's own patents and design work would be relevant.
Q4: Are method claims enforceable without patenting specific compounds?
Method claims are enforceable if the method involves compounds protected by the composition claims or if the method is sufficiently specific.
Q5: What are the key considerations for patent drafting in this space today?
Claims should balance broad chemical coverage with detailed medicinal use, while navigating existing patents to avoid infringement and ensure freedom-to-operate.
7. Key Takeaways
- US Patent 6,123,962 provides extensive protection for thalidomide derivatives used in anti-cancer therapy, specifically targeting angiogenesis inhibition.
- The patent’s broad claims cover compositions and methods, influencing subsequent derivative development and therapeutic strategies.
- The patent landscape reveals overlapping claims in related patents, emphasizing strategic patent fencing in this field.
- Expiration nearly coincided with the early 2010s, but related patents and newer filings keep the competitive environment active.
- Companies developing anti-angiogenic or immunomodulatory drugs must carefully review patent claims and family members to assess freedom-to-operate.
References
- U.S. Patent No. 6,123,962, "Method of inhibiting the growth of malignant cells," filed July 6, 1998, issued September 26, 2000.
- U.S. Patent No. 5,763,423, "Thalidomide analogs with immunomodulatory activity," filed July 22, 1994, issued June 9, 1998.
- U.S. Patent No. 6,255,423, "Methods for inhibiting angiogenesis," filed August 30, 1999, issued July 3, 2001.
- WO 97/43429, "Thalidomide derivatives as anti-tumor agents," published July 24, 1997.
- Market reports on thalidomide derivatives and anti-angiogenic therapies, 2020-2022.
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