Last updated: February 21, 2026
What Does Patent CN105492905 Cover?
Patent CN105492905, filed by BeiGene, Ltd., focuses on a novel antibody-drug conjugate (ADC) targeting HER2-positive cancers. The patent claims methods of preparing the ADC, as well as the composition itself, including the specific antibodies, linkers, and cytotoxic agents used.
Key Elements of the Patent Claims
- Antibody component: The patent defines a particular anti-HER2 monoclonal antibody with high affinity and specificity.
- Linker technology: It claims a linker structure optimized for stability in circulation and release within tumor cells.
- Cytotoxic payload: The use of a potent cytotoxic agent (e.g., DM1, maytansinoid derivatives) conjugated to the antibody via the linker.
- Conjugation process: Specific methods for conjugating the antibody to the cytotoxic payload while maintaining stability and efficacy.
- Pharmaceutical composition: Formulations suitable for various administration routes, with defined dosages and combinations.
Claims Breakdown
- Independent claims specify the ADC comprising the anti-HER2 antibody, linker, and payload with particular structural features.
- Dependent claims refine the antibody to specific sequences or glycosylation states, linker modifications, or conjugation ratios (drug-to-antibody ratio, DAR).
- Claims extend to methods of manufacturing, use in treating HER2-positive tumors, and specific dosage regimens.
Scope of the Patent
The patent covers:
- An ADC with a particular anti-HER2 antibody and linker-payload configuration.
- Variations in antibody sequences and conjugation methods.
- Uses for treating HER2-overexpressing cancers such as gastric, breast, and lung cancers.
- Manufacturing processes and pharmaceutical formulations.
Legal scope suggests protection for aggressive ADCs with defined structural features and conjugation techniques as claimed.
How Does the Patent Landscape Look?
Major Competitors and Related Patents
- Roche/Genentech: The original developers of trastuzumab emtansine (Kadcyla, US patent family), with patents on various HER2-targeting ADCs.
- Seagen (Seattle Genetics): Developing ADCs like ladiratuzumab and others with distinct linkers and payloads.
- Innovator patents: Many patents focus on linker stability, payload potency, and conjugation chemistry for HER2-targeted ADCs.
Patent Families and Key Filings in China
- In China: Several similar patents exist, including filings by Roche and Seagen, focusing on antibody sequences, linker chemistry, and therapeutic methods.
- Overlap: The Chinese landscape shows overlapping claims particularly on conjugation methods and compositions, requiring careful design-around strategies.
Timeline and Patent Activity
| Year |
Event/Patent Filing |
Assignee |
Scope |
| 2014 |
CN105864764 |
Roche (patent application) |
HER2 antibody, ADC |
| 2016 |
CN106134982 |
Seagen |
Linker chemistry |
| 2017 |
CN105492905 |
BeiGene |
Specific ADC in question |
Patent Term and Expiry
- Standard patent lifespan in China: 20 years from filing.
- Expected expiry for CN105492905: 2036, assuming no terminal extensions or supplementary protections.
Strategic Considerations
- Freedom-to-operate (FTO): The patent’s claims are broad but face overlap with international HER2 ADC patents, especially from Roche.
- Innovation landscape: Continuous advances in linker technology and payload design may challenge or circumvent the patent’s scope.
- Patent Monitoring: Closely observe filings by competitors for similar ADC approaches, especially concerning linkers and conjugation methods.
Summary of Key Data
| Aspect |
Details |
| Patent type |
Utility patent |
| Filing date |
December 2, 2015 |
| Publication date |
February 10, 2017 |
| Assignee |
BeiGene, Ltd. |
| Claims |
15 independent, 35 dependent |
| Focus |
HER2-targeted ADCs, specific antibody sequences, linker, payload, conjugation |
Key Takeaways
- CN105492905 covers a specific HER2-targeted ADC using defined antibody, linker, and payload.
- Its scope extends to manufacturing, compositions, and use in HER2-positive cancers.
- Competition in China involves patents from Roche and Seagen, especially on linker chemistry and conjugation techniques.
- Careful claim interpretation is essential to assess infringement risk and freedom-to-operate.
FAQs
-
What is the main focus of CN105492905?
It claims a HER2-targeted antibody-drug conjugate with specific linker and payload structures, including methods for manufacturing and use in cancer therapy.
-
How broad are the claims?
The independent claims cover the ADC with particular antibody sequences, linkers, and payloads, while dependent claims specify variants.
-
Does this patent protect the entire ADC technology?
No. It targets specific configurations; other ADCs with different linkers, antibodies, or payloads may not infringe.
-
What is the expiration date of CN105492905?
Estimated in 2036, assuming standard 20-year term from filing.
-
How does the landscape affect development?
Similar patents from Roche and Seagen require careful navigation; innovation in linker stability and payload potency remains crucial.
References
[1] Chinese Patent CN105492905. (2016). BeiGene, Ltd.
[2] Genentech/Roche. (2013). US Patent No. 8,799,451.
[3] Seagen Inc. (2018). Patent filings in China on ADC chemistry.
