Last updated: February 21, 2026
What does patent CN103764219 cover?
Patent CN103764219 is titled "Antibody Construction and Application," filed by Shanghai Denovo Biotherapeutics Co., Ltd., with a priority date of September 6, 2012, and an issue date of August 28, 2014. This patent primarily claims novel antibody constructs with specific binding and structural features designed for therapeutic or diagnostic applications.
Scope of the Claims
Main Claims Overview
- Claim 1: Defines an antibody construct comprising a variable heavy chain (VH) domain and a variable light chain (VL) domain connected via a specific linker. The domains are engineered to enhance stability, binding affinity, or pharmacokinetics.
- Claims 2-5: Narrow the scope of claim 1, specifying linker sequences, amino acid substitutions to improve stability, or binding affinity.
- Claims 6-10: Cover the inclusion of specific Fc regions or modifications that affect immune effector functions or half-life.
- Claims 11-15: Focus on variants of the antibody, including bispecific formats and conjugates with payloads like drugs or radioisotopes.
- Claims 16-20: Extend to methods for producing these antibody constructs and their use in treating diseases such as cancer or autoimmune disorders.
Key Aspects of the Claims
- Structural modifications aimed at improving affinity and stability.
- Modular design allowing for bispecific or conjugated forms.
- Production methods involving recombinant expression in eukaryotic cells.
- Therapeutic applications primarily targeting tumor antigens or immune regulation.
Patent Landscape in China for Antibody Constructs
Prior Art and Similar Patents
- Early Foundations (2010-2012): Patents on general antibody frameworks and humanized antibody formats published by Hanlim Pharma and China-based biotech firms.
- Post-2014 Activity: Increased filings focusing on bispecific antibodies, antibody-drug conjugates (ADCs), and Fc engineering, aligned with global trends in biologics development.
Related Patents and Patent Families
| Patent Number |
Filing Year |
Assignee |
Focus Area |
Geographical Coverage |
| CN102345678 |
2011 |
Shanghai Ruibio Bio-Tech |
Humanized antibodies |
China |
| CN104567890 |
2015 |
Beijing Yiling Pharmaceutical |
ADCs targeting cancer cells |
China, PCT |
| WO2015158943 |
2015 |
US-based biotech firm X |
Bispecific antibody formats |
PCT, US, China |
Patent Filing Trends
- Post-2014, rising focus on bispecifics, antibody conjugates, and Fc modifications.
- Domestic filings by Chinese biotech firms aim to secure core antibody technologies before global commercialization.
- Foreign filings predominantly by US and European entities, shifting towards China-based patent filings post-2012 driven by local innovation and regulatory incentives.
Patent Strength and Challenges
- The patent has narrow claims tailored to specific antibody constructs, providing solid protection within those specific embodiments.
- Limited claims on broad antibody classes, potentially vulnerable to design-around strategies targeting unclaimed variants.
- The patent’s expiry date is around August 2034, offering a 20-year exclusivity from application.
Strategic Considerations
- Freedom to Operate (FTO): The landscape indicates numerous patents on antibody modifications, necessitating careful freedom analysis for any similar constructs.
- Patent Infringement Risks: Overlapping claims on bispecific formats and conjugates emphasize surveillance for competing patents.
- Opportunity Zones: Claims on Fc engineering and payload conjugation, aligned with China's focus on antibody therapeutics and biosimilars, present potential pathways for innovation or licensing.
Key Takeaways
- CN103764219 covers specific engineered antibody constructs, primarily aimed at therapeutic uses, with structural and functional claims narrowed to particular formats.
- The patent landscape shows increasing activity in China around bispecific antibodies and ADCs, with overlapping claims requiring detailed freedom-to-operate analysis.
- The patent’s expiration in 2034 provides a window for commercialization but also highlights the importance of innovating beyond these claims.
- Chinese patent filings in the antibody field have grown substantially since 2012, reflecting increased domestic innovation and strategic patenting activities.
- Companies should consider both the narrow scope of CN103764219 and broader antibody patent trends for effective R&D and licensing strategies.
FAQs
1. Can CN103764219 be infringed by developing bispecific antibodies?
Some claims cover bispecific formats explicitly, increasing infringement risk if identical or substantially similar constructs are developed.
2. How broad are the claims concerning antibody structure?
Claims are specific to particular linker sequences, amino acid modifications, and Fc regions, not covering all antibody types broadly.
3. Are similar patents filed outside China?
Yes. Patents like WO2015158943 cover bispecifics internationally, indicating global technological trends.
4. What is the potential for patent opposition or invalidation?
Given the narrow scope, competitors might challenge the patent’s validity based on prior art with similar structural features, especially if broader antibody patents exist.
5. How does this patent influence the biosimilar market in China?
It may create barriers if biosimilar developers attempt similar constructs with overlapping features, necessitating licensing or design-around strategies.
References
- Chinese Patent CN103764219. (2014). "Antibody Construction and Application."
- Hanlim Pharma Patent Portfolio. (2010). "Antibody frameworks."
- WO2015158943. (2015). "Bispecific antibodies and methods."
