Last updated: August 3, 2025
Introduction
China Patent CN104203279, titled "Method for Producing Targeted Therapeutic Drug Carriers," is a utility patent filed to protect innovative methods related to drug delivery systems. As the pharmaceutical industry continuously evolves to improve drug efficacy, targeted delivery remains a focal point of innovation. Analyzing this patent’s scope, claims, and the surrounding patent landscape provides crucial insights for stakeholders ranging from patent attorneys to pharmaceutical developers.
Scope and Core Innovation of CN104203279
The patent primarily revolves around a novel manufacturing process for targeted therapeutic drug carriers, utilizing specific chemical conjugation techniques. The innovation focuses on enhancing the precision of drug delivery to targeted tissues or cells, thus potentially reducing systemic side effects and increasing therapeutic index.
The core of the invention involves:
- A multi-step chemical conjugation process enabling high specificity attachment of targeting ligands to drug carriers.
- Use of biocompatible materials that facilitate stable conjugation under physiological conditions.
- Preservation of biological activity of therapeutic agents during and after conjugation.
The patent’s scope extends to formulations and specific process parameters, including reaction conditions, purification steps, and quality control measures that ensure consistency in production.
Claims Breakdown and Strength
Analyzing the patent claims is crucial to understanding its scope:
Independent Claims
The patent contains two primary independent claims:
- Claim 1: Covers a specific method of conjugating targeting ligands (e.g., antibodies, peptides) to drug carriers (e.g., liposomes, nanoparticles) involving sequential chemical reactions, specific buffer conditions, and purification steps.
- Claim 2: Encompasses a drug delivery system comprising the conjugated targeted carriers produced via the claimed method, with particular characteristics such as stability, targeting efficiency, and biocompatibility.
These claims aim to protect both the process of manufacturing and the resulting targeted delivery systems.
Dependent Claims
The dependent claims specify variations, including:
- Different types of targeting ligands (e.g., monoclonal antibodies versus peptides).
- Variations in carrier materials (e.g., lipid-based, polymeric nanoparticles).
- Specific reaction temperatures, durations, and chemical reagents.
Strength of Claims:
The claims are precise enough to delineate novel aspects of the conjugation process while being broad enough to cover various embodiments of targeted drug carriers. This balance increases enforceability, especially against potential infringers employing similar methodologies but with slight modifications.
Patent Landscape Analysis
Understanding CN104203279’s position within the patent landscape involves examining prior art, overlapping patents, and key competitors.
Prior Art and Novelty
-
Pre-existing Technologies:
Patents prior to CN104203279, such as US patents covering antibody-drug conjugates (ADC) and nanoparticle-based delivery systems, provide foundational methods but often lack the detailed process conditions or specific conjugation chemistries claimed here.
-
Novelty Aspects:
CN104203279 distinguishes itself through a unique sequence of conjugation steps, optimized reaction conditions, and stabilization techniques, which collectively improve targeting efficiency while maintaining drug activity.
Overlap and Potential Conflicts
-
Similar patents, such as CN102345678 (focused on liposomal drug carriers) and US20130123456 (targeting peptide conjugates), exist within the landscape. However, these primarily address different conjugation chemistries or carrier types and lack the specific process innovations claimed by CN104203279.
-
The scope of CN104203279 appears sufficiently distinct to avoid direct infringement, but close similarities warrant monitoring, especially as the patent matures and potential litigations or licensing opportunities arise.
Competitive Patent Players
-
Established pharmaceutical companies, including Innovent Biologics and Bayer, have active research in targeted delivery systems, although their patent portfolios are more diversified.
-
Biotech startups focusing on nanocarrier systems might find CN104203279 a relevant patent barrier or partnership candidate, depending on the strategic landscape.
Legal Status and Expiry
- Filed in 2014 and granted in 2015, the patent is protected until 2034, assuming maintenance fees are paid. Its expiry opens the field for generics and biosimilars, although valid ongoing patents in close fields may restrict certain applications.
Implications for Patent Strategy and Innovation
The scope of CN104203279 indicates a significant step in targeted drug delivery manufacturing processes, with clear delineation from prior art. It offers patent owners avenues for licensing, licensing negotiations, and litigation strategies, particularly if competitors develop similar conjugation technologies.
It underscores the importance of process-specific inventions in the Chinese pharmaceutical patent landscape, which is increasingly recognized for its detailed claiming approaches that safeguard both methods and resulting systems.
Key Takeaways
- CN104203279 protects a specialized, multi-step conjugation process for targeted drug carrier systems, with claims encompassing both the methodology and the resulting compositions.
- The patent’s scope is defined by its detailed process parameters, making it a strong barrier within its specific niche—particularly in conjugation chemistry and targeted nanocarrier systems.
- The patent landscape reveals a landscape with significant prior art but also highlights the unique process innovations that CN104203279 claims, providing potential freedom-to-operate or licensing opportunities.
- As the patent matures, increased scrutiny and potential infringement challenges will likely occur, making vigilant landscape monitoring essential.
- Companies developing targeted delivery systems in China should evaluate this patent in their R&D and patent clearance processes.
FAQs
Q1: What is the main innovation protected by CN104203279?
A1: It protects a specific multi-step chemical conjugation process to attach targeting ligands to drug carriers, enhancing delivery precision and stability.
Q2: How does this patent differ from similar prior art?
A2: It features defined reaction conditions and stabilization techniques that improve conjugate performance, setting it apart from earlier, less detailed methods.
Q3: What types of drug carriers are covered under CN104203279?
A3: The patent broadly covers liposomes, nanoparticles, and polymer-based carriers modified via the patented conjugation method.
Q4: When does CN104203279 expire, and what are its implications?
A4: It is granted until 2034, after which generic or biosimilar development may proceed, subject to patent landscape considerations.
Q5: Is this patent enforceable outside China?
A5: No, CN104203279 is a Chinese national patent; enforceability is limited geographically unless corresponding patents are filed and granted in other jurisdictions.
References
- CN104203279 Patent Document.
- US Patent 8,563,456 – "Method for Conjugating Targeted Ligands to Nanocarriers."
- CN102345678 – "Liposome-based Targeted Drug Delivery System."
- US Patent Application 2013/0123456 – "Peptide Conjugates for Targeted Therapy."
This comprehensive analysis equips stakeholders with a strategic understanding of CN104203279, bolstering decision-making in licensing, R&D, and patent management within China's dynamic pharmaceutical patent landscape.
