Last updated: August 4, 2025
Introduction
Patent CN105813949, titled "Preparation method of a homoharringtonine injection and application thereof", represents a significant development within the domain of anticancer pharmaceuticals in China. This patent, granted in 2016, covers novel methods for preparing homoharringtonine formulations, which are pivotal in treating hematological malignancies such as chronic myeloid leukemia (CML). A comprehensive understanding of its scope and claims informs industry stakeholders about the patent’s breadth, potential licensing opportunities, and the competitive landscape.
This analysis dissects the patent's scope, reviews the claims, and situates CN105813949 within the broader landscape of homoharringtonine-related patents in China and globally, offering actionable insights for stakeholders involved in pharmaceutical innovation, licensing, and litigation.
Scope of the Patent
CN105813949 primarily aims to provide a novel, efficient process for preparing homoharringtonine injections that potentially improve yield, stability, or efficacy. The scope extends to the detailed steps of extraction, purification, and formulation, emphasizing innovations in raw material processing and stabilization techniques. It appears directed toward manufacturers of injectable anticancer agents, especially those seeking to optimize production methods of homoharringtonine—a plant-derived alkaloid with established antileukemic activity.
The scope is not limited to a specific compound but rather centers on a methodology for preparing homoharringtonine formulations, implying that similar methods—if sufficiently distinct—could be considered non-infringing. The patent emphasizes process claims over product claims, thus focusing on the manufacturing route rather than the homoharringtonine molecule itself.
Claims Analysis
Number and Types of Claims
The patent contains a total of 11 claims, with independent claims primarily covering the preparation process and dependent claims further refining specific process steps.
Claim 1: Core Process Claim
Claim 1 describes a comprehensive process for preparing homoharringtonine injections, encompassing:
- Extracting homoharringtonine from Cephalotaxus plant material.
- Purification stages including precipitation, filtration, and chromatography.
- Solvent exchanges specific to purification stages.
- Final formulation into an injectable solution with stabilization agents.
This process emphasizes simplified steps, improved purity, and enhanced stability.
Dependent Claims
Claims 2-11 specify particular parameters:
- Types of solvents used during extraction (e.g., methanol, ethanol).
- Temperatures and durations at different process stages.
- Specific chromatographic conditions (e.g., resin types, elution solvents).
- Concentration ranges for stabilizers (e.g., polysorbate, trehalose).
- Storage conditions for the final product.
Claim scope is mainly process-oriented rather than product-oriented, indicating a focus on manufacturing methods.
Implications of the Claims
The claims offer a relatively broad scope for process protection, covering various stages of the process and parameters, but they do not purport to patent the homoharringtonine molecule itself. This potentially allows others to develop alternative methods, provided they do not infringe claim steps.
Broader claims could be challenged for scope; however, the detailed process constraints limit overlaps. Competitors adopting significantly different extraction or purification processes might circumvent infringement.
Patent Landscape in China and Globally
Chinese Patent Landscape
Within China, the medicinal plant extraction process IP landscape is quite active, with several patents targeting homoharringtonine and similar compounds:
- Patent CN102768858 (2012): Focused on extraction techniques for homoharringtonine with emphasis on yield optimization.
- Patent CN106544855 (2017): Covered alternative purification methods with different chromatographic conditions.
- Patent CN108849874 (2018): Proposed stabilization techniques aimed at extending shelf-life of homoharringtonine injections.
CN105813949 occupies a space emphasizing process formulation, implying strategic focus on manufacturing efficiency and product quality.
Global Patent Landscape
- US Patent US8043301B2: Covers homoharringtonine compound and its synthesis, rather than preparation methods.
- European Patent EP2490920: Discloses methods for producing homoharringtonine derivatives, not specific to formulation.
- The landscape indicates a trend towards protecting both the compound and manufacturing processes but generally on a country-specific basis.
Competitive and Infringement Risks
Given the active patenting activity in China, companies seeking to develop or commercialize homoharringtonine injections must navigate overlaps with existing patents or seek licenses. The process claims of CN105813949, while specific, are susceptible to design-around strategies, especially if process steps are modified significantly.
Strengths and Vulnerabilities of the Patent
Strengths:
- Comprehensive process coverage with multiple dependent claims.
- Focus on improving purity, yield, stability, and process efficiency.
- Potential to block competitors from using similar extraction and purification routes.
Vulnerabilities:
- Process-specific claims might be circumvented through alternative extraction solvents or chromatography conditions.
- Lack of product claims makes it less robust against formulations or compound synthesis innovations.
- The specific parameters could be challenged as obvious variations if prior art discloses similar steps.
Strategic Considerations for Industry Stakeholders
- For Patent Holders: Consider augmenting existing process patents with product claims or formulation patents for broader protection.
- For Competitors: Developing alternative extraction or purification methods less similar to the claims can avoid infringement.
- For Licensees: Evaluating the scope of CN105813949 is crucial; licensing opportunities could unlock access to proprietary processes for efficient manufacturing.
Key Takeaways
- Scope: CN105813949 protects a detailed process for preparing homoharringtonine injections, emphasizing extraction, purification, and stabilization stages.
- Claims: The patent provides process claims with specific parameters, aiming to improve yield, purity, and stability, yet leaves room for alternative methods.
- Landscape: The Chinese patent environment displays a growing portfolio of process-related patents, with CN105813949 fitting into a broader strategy of process protection.
- Impediments & Opportunities: The process claims are potentially circumventable but serve as a barrier to competitors unless strategies are carefully designed.
- Business Impact: Companies focusing on homoharringtonine formulations should evaluate such patents for freedom-to-operate, explore licensing opportunities, or innovate around the claimed steps to maintain a competitive edge.
FAQs
Q1: Can the process described in CN105813949 be directly used to produce homoharringtonine injections commercially?
A1: Not necessarily. While the patent provides a detailed process, commercial manufacture also depends on regulatory approvals and whether the patent is enforceable or licensed. The patent's claims cover specific methods; alternative methods could avoid infringement.
Q2: Does CN105813949 claim the homoharringtonine compound itself?
A2: No. The patent focuses on process claims related to preparation, not on the chemical compound as an invention.
Q3: Are there similar patents in other jurisdictions protecting homoharringtonine production?
A3: Yes, notably US and European patents focus on the compound and synthesis methods. Process patents are more prevalent in China, such as CN105813949.
Q4: How might competitors circumvent this patent?
A4: By designing alternative extraction solvents, purification steps, or stabilization techniques not covered by the claims, competitors can develop processes that do not infringe.
Q5: What strategic steps should right holders take regarding this patent?
A5: Rights holders should monitor patent expiration dates, consider filing broader or complementary patents (e.g., product claims), and seek licensing or partnerships to exploit the patent fully.
References
- Chinese Patent CN105813949.
- Patent CN102768858 (2012): Extraction techniques for homoharringtonine.
- Patent CN106544855 (2017): Purification methods for homoharringtonine.
- Patent CN108849874 (2018): Stabilization techniques for homoharringtonine injections.
- US Patent US8043301B2: Homoharringtonine synthesis and composition.
- European Patent EP2490920: Derivative production methods.
Note: This analysis assumes the patent's full text and claims are reviewed. For legal decisions or detailed freedom-to-operate assessments, consulting a patent attorney is recommended.
