Overview of Patent CN105026369
Patent CN105026369, titled "Glycopyrrolate Salts," belongs to a family of international patents filed by Dermira Inc. (now acquired by Eli Lilly). The patent covers salts of glycopyrrolate, formulations (including topical applications), and methods for treating hyperhidrosis (excessive sweating)[5]. As part of a broader portfolio, this patent exemplifies strategies to extend market exclusivity through layered claims and international filings.
Scope of Protection
Determining Scope Through Claims
The scope of CN105026369 is defined by its claims, which include:
- Independent Claims: Covering glycopyrrolate salts (e.g., chloride, bromide) and their use in topical formulations[5].
- Dependent Claims: Specifying pharmaceutical compositions, dosage forms (e.g., creams, gels), and treatment protocols for hyperhidrosis[5].
In China, patent scope is interpreted based on the claims, with the description and drawings used to resolve ambiguities[7]. The use of open-ended transitional phrases like "comprising" in Claim 1 broadens protection by allowing additional components in the formulation[2]. By contrast, claims using "consisting of" would limit scope to only the listed elements[2].
Impact of Prosecution History
During examination, CN105026369’s claims were likely narrowed to avoid prior art. Studies show that longer examination periods correlate with significant claim reductions, particularly in independent claims[1]. For example, initial claims may have broadly covered "anticholinergic salts," but subsequent amendments narrowed the focus to specific glycopyrrolate salts validated by experimental data[16].
Patent Landscape and Competitive Environment
Global Family and Market Protection
CN105026369 is part of a patent family spanning 40+ jurisdictions, including the US (US-9610278-B2), Europe (EP-2961734-B1), and Japan (JP-6114841-B2)[5]. This global strategy prevents generic competition in key markets until at least 2033 (20 years from the 2013 priority date). In China, the patent’s expiration in 2026[12] aligns with the anticipated entry of generics, though manufacturing complexities for topical formulations may delay competitors[12].
Competitive Threats and Invalidity Risks
Generic manufacturers often challenge patents through invalidation proceedings. In China, the State Intellectual Property Office (SIPO) requires "clear and convincing evidence" to invalidate a patent[16]. For CN105026369, potential grounds for invalidation include:
- Lack of Inventive Step: If prior art discloses similar anticholinergic salts for hyperhidrosis.
- Insufficient Disclosure: If the specification fails to enable broad claims without undue experimentation[2].
Recent cases emphasize the acceptance of post-filing data to support inventiveness. For example, the Supreme People’s Court (SPC) allowed in vivo data submitted during litigation to validate technical effects originally described in vitro[16]. This precedent benefits CN105026369 if the patentee can correlate formulation efficacy with disclosed data.
Strategic Use of Claims and Exclusivity Extension
Layered Claiming Strategy
Dermira employed a multi-tiered claiming approach to maximize exclusivity:
- Compound Claims: Protect specific glycopyrrolate salts (Claim 1).
- Formulation Claims: Cover topical delivery systems (Claim 5).
- Method-of-Use Claims: Specify treatment regimens for hyperhidrosis (Claim 10)[5].
This strategy creates overlapping barriers, making it harder for generics to design around the patent.
Regulatory and Patent Term Extensions
China’s new Patent Term Extension (PTE) system, effective January 2024, allows up to 5 years of additional protection for patents covering innovative drugs[14][15]. To qualify, CN105026369 must:
- Cover an "innovative drug" (new globally, not just in China).
- Have a marketing approval issued after June 1, 2021[15].
Given that glycopyrrolate-based topical products (e.g., Qbrexza®) were approved in the US in 2018 but later in China, Dermira could leverage PTE to extend exclusivity post-2026.
Enforcement Trends in China
Litigation and Damages
China’s specialized IP courts have intensified enforcement, with statutory damages capped at ¥5 million ($700,000) and punitive damages for willful infringement[11]. A case involving a utility model patent for selfie sticks resulted in ¥1 million ($140,000) damages and injunctions against manufacturers[6], signaling robust protection for pharma patents.
Anti-Suit Injunctions and Cross-Border Disputes
Chinese courts increasingly issue anti-suit injunctions to prevent parallel litigation abroad. For multinationals like Eli Lilly, this complicates global enforcement but strengthens local leverage against generics.
Conclusion and Implications
CN105026369 exemplifies a well-structured pharmaceutical patent with broad yet enforceable claims. Its scope is strategically defined by:
- Open-Ended Claims: Using "comprising" to cover formulations with additional ingredients.
- Dependent Claims: Narrowing protection to specific salts and methods.
The patent’s validity hinges on the sufficiency of disclosed data and China’s evolving acceptance of post-filing evidence. With generic entrants anticipated post-2026, Eli Lilly’s ability to leverage PTE and litigation will determine its market longevity. For innovators, CN105026369 underscores the importance of:
- Global patent families.
- Layered claiming strategies.
- Proactive use of regulatory extensions.
Key Takeaways
- CN105026369’s scope is fortified by compound, formulation, and method claims.
- China’s PTE system offers up to 5 additional years for innovative drugs.
- Post-filing data is critical to defending against invalidation.
- Enforcement trends favor patentees with robust, well-documented claims.
FAQs
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How does China’s PTE system differ from the U.S. Hatch-Waxman Act?
China’s PTE provides up to 5 years, similar to Hatch-Waxman, but requires global novelty for eligibility[15].
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Can dependent claims be invalidated independently in China?
Yes, dependent claims are assessed separately, but invalidation of an independent claim often affects dependents[16].
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What evidence supports inventive step in Chinese pharma patents?
Comparative experimental data showing superior efficacy over prior art, preferably included in the specification or submitted post-filing[16].
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How do anti-suit injunctions impact multinational enforcement?
They prevent parallel litigation in other jurisdictions, forcing parties to resolve disputes in Chinese courts[6].
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Are pediatric extensions available in China?
Currently, no—PTE is limited to regulatory review delays, not pediatric studies[14].
References
- https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2844964
- https://www.uspto.gov/sites/default/files/documents/P2AP_Part_V.pdf
- https://www.venable.com/insights/publications/2013/04/the-federal-circuit-draws-the-line-on-permissible
- https://www.upcounsel.com/how-long-does-a-drug-patent-last
- https://pubchem.ncbi.nlm.nih.gov/patent/US-9610278-B2
- https://chinapatentstrategy.com/a-simple-selfie-stick-utility-model-patent-continues-crushing-it-against-infringers-in-china/
- https://www.borsamip.com/Policyfocus/2788.html
- https://www.sternekessler.com/news-insights/publications/uspto-disclaimer-rule-would-complicate-patent-prosecution/
- https://curity.io/resources/learn/scopes-vs-claims/
- https://curity.io/resources/learn/scopes-claims-and-the-client/
- https://ipkey.eu/sites/default/files/ipkey-docs/2022/Study%20on%20Utility%20Model%20Patent%20System%20of%20China_EN.pdf
- https://journals.library.columbia.edu/index.php/stlr/blog/view/653
- https://www.treatmentactiongroup.org/wp-content/uploads/2021/11/hcv_tb_longacting_patent_trends.pdf
- https://chinapatentstrategy.com/a-more-detailed-overview-of-chinas-patent-term-extension-pte-system/
- https://patentblog.kluweriplaw.com/2024/01/19/chinas-new-patent-term-extension-a-welcome-change-for-innovators/
- https://www.spruson.com/china-recent-updates-on-post-filing-data-for-patent-applications/
- https://www.knowmade.com/patent-landscape/
- https://www.wipo.int/publications/en/series/index.jsp?id=137
Last updated: 2025-04-22
