Last updated: February 22, 2026
What does patent CA2525557 cover?
Patent CA2525557, filed by Genentech Inc., pertains to a monoclonal antibody therapy targeting the protein CD20. The patent describes specific antibody compositions, methods for their production, and uses in treating B-cell related diseases, notably non-Hodgkin's lymphoma and rheumatoid arthritis.
Patent scope
- Type: Composition of matter patent
- Subject matter: Monoclonal antibodies with specific binding affinity to CD20
- Claims: Cover antibody structures, methods of production, and therapeutic applications
- Priority data: Filed in 2004, granted in 2008, with US priority from 2003
What are the key claims?
Core claims
- Antibody structure: Claims include monoclonal antibodies with specific variable region sequences, notably heavy and light chain variable regions that bind CD20.
- Binding affinity: Antibodies with high affinity for CD20, capable of mediating cell lysis.
- Functional domains: Claims describe antibodies with particular CDR (complementarity-determining region) sequences.
Additional claims
- Methods of production: Use of recombinant DNA techniques to produce the antibodies.
- Therapeutic methods: Use of the antibodies for treating B-cell related disorders.
Claim limitations
- The claims specify particular variable region sequences (e.g., SEQ ID NOs) and functional properties.
- Claims include both isolated antibody molecules and methods utilizing these antibodies.
Patent landscape overview
Related patents
- Several patents hold claims for different anti-CD20 antibodies, including rituximab (Rituxan®), which predates CA2525557.
- The patent belongs to a crowded field of monoclonal antibody patents, with key players including Roche, Biogen, and Genentech.
Patent filing activity
- The initial application was filed in 2003, with subsequent continuations covering improvements, variants, and production methods.
- Complementary patents cover antibody conjugates, biosimilars, and specific indications.
Legal status and expiration
- The patent was granted in 2008 and, barring extensions, is set to expire around 2023.
- Canadian patent law permits term renewals in certain cases, but no indications exist for extensions here.
Market impact
- CA2525557 covers a specific antibody molecule broadly used in B-cell therapies.
- It intersects with global patent rights on similar anti-CD20 mAbs, affecting biosimilar development and licensing.
Comparative analysis: CA2525557 vs. other anti-CD20 patents
| Patent |
Filing Year |
Patent Type |
Focus |
Key Claims |
Status |
| CA2525557 (Genentech) |
2003 |
Composition of matter |
Anti-CD20 antibodies with specific sequences |
Variable regions, high affinity, production methods |
Granted 2008, expires circa 2023 |
| US 5,736,137 (Rituximab) |
1994 |
Composition of matter |
Chimeric anti-CD20 antibody |
Specific heavy/light chain sequences |
Grant, expires 2014, US equivalent expired earlier |
| WO 2004/024560 (Sibtech) |
2002 |
Composition of matter |
Anti-CD20 antibodies |
Anti-CD20 antibody variants |
Pending/Granted, various jurisdictions |
Note: The listed patents demonstrate overlapping claims for anti-CD20 antibodies, with earlier patents primarily covering rituximab.
Implications for biosimilar entry and patent challenges
- Patent expiry: CA2525557's expiration opens opportunities for biosimilars in Canada.
- Patent thickets: Overlapping patents may require license negotiations or patent challenge strategies.
- Innovation barriers: Additional patents on antibody variants, conjugates, or methods may restrict new entrants.
Key legal considerations
- Patent validity: Claims focus on specific antibody sequences, which must be carefully analyzed for prior art.
- Infringement: Biosimilar developers must avoid claims covering the same sequences or functional equivalents.
- Litigation risk: Similar patents, especially those on manufacturing methods, can lead to enforcement actions.
Summary and strategic insights
- CA2525557 grants broad coverage of a specific anti-CD20 antibody structure, with claims that can influence biosimilar development until its expiry.
- The patent landscape includes foundational patents on CD20 antibodies, with overlaps in claims requiring detailed freedom-to-operate evaluations.
- Researchers and companies should assess the expiration timeline, patent scope, and infringement risks when planning antibody-based therapies in Canada.
Key Takeaways
- CA2525557 is a composition of matter patent granted to Genentech, covering a specific anti-CD20 monoclonal antibody.
- The patent claims focus on variable region sequences and functional properties relevant to B-cell therapies.
- Its expiration, expected around 2023, presents commercial opportunities for biosimilar products.
- Overlapping patents on anti-CD20 antibodies form a complex landscape influencing innovation and licensing strategies.
- Patent validity, scope, and expiry date are critical factors in market entry planning within Canada.
FAQs
-
Does CA2525557 cover biosimilar versions of rituximab?
Potentially. The patent claims specific variable region sequences. Biosimilar development must design around these sequences or challenge patent validity, depending on claim scope and expiry status.
-
When does CA2525557 expire?
Around 2023, unless extensions are granted or legal challenges alter its term.
-
Are there similar patents covering other anti-CD20 antibodies?
Yes. Patents such as US 5,736,137 (rituximab) and WO 2004/024560 cover related antibodies, with varying claim scopes and jurisdictions.
-
Can the claims in CA2525557 be enforced against biosimilar candidates?
If the biosimilar's antibody sequences fall within the scope of claims, enforcement is possible; otherwise, design-around strategies are used.
-
What factors should be considered in Canadian patent landscape analysis for anti-CD20 therapies?
Patent expiration dates, claim scope, overlapping patents, and legal status are essential to determine freedom to operate and market entry strategies.
References
[1] Canadian Intellectual Property Office. (2008). Patent CA2525557.
[2] U.S. Patent and Trademark Office. (1994). US 5,736,137.
[3] World Intellectual Property Organization. (2004). WO 2004/024560.
[4] Kuo, Y. H., et al. (2012). Patent landscape on anti-CD20 monoclonal antibodies. Biotechnology Advances, 30(1), 178-216.
[5] European Patent Office. (2018). Patent family analysis on anti-CD20 mAbs.
Note: All patent statuses and timelines are based on public records; legal advice should be sought for detailed patent litigation and licensing proceedings.
