Last updated: July 27, 2025
Introduction
China Patent CN116059313, titled "Method for preparing sodium phenylbutyrate and the product thereof," filed by BeiGene, Ltd., presents a novel approach to synthesizing sodium phenylbutyrate (SPB), a widely used histone deacetylase (HDAC) inhibitor in cancer therapy. This patent plays a strategic role within China's pharmaceutical patent landscape, especially given the expanding focus on targeted cancer treatments. It claims an innovative process to facilitate commercial manufacturing, positioning it as a valuable asset amidst the rapidly evolving chemical and pharmaceutical patents in China.
This analysis provides a comprehensive review of the patent's scope, claims, and its placement within the patent landscape, essential for pharmaceutical companies, legal professionals, and R&D strategists seeking insight into its potential enforceability, infringement risks, and strategic value.
Patent Overview and Key Highlights
- Patent Number: CN116059313
- Filing Date: August 2019
- Grant Date: January 2023
- Applicant: BeiGene, Ltd.
- Technology Area: Chemical synthesis, pharmaceutical intermediates, and drug manufacturing processes
Abstract:
The patent discloses a simplified, efficient process for preparing sodium phenylbutyrate, emphasizing high yield, purity, and process safety. The process involves specific reaction conditions that minimize by-products, optimize reaction efficiency, and facilitate scale-up.
Scope of the Patent
The scope of CN116059313 centers around the methodology for synthesizing sodium phenylbutyrate, encompassing specific reaction steps, conditions, and intermediate purification techniques. Central to its scope are:
- Reactant selection: Utilizing particular precursors and catalysts that improve reaction efficiency.
- Reaction conditions: Emphasizing temperature, solvent choice, pH optimization, and reaction time for maximized yield and purity.
- Purification processes: Techniques such as crystallization and filtration tailored to obtain high-grade SPB.
- Process safety and environmental considerations: Incorporation of conditions that reduce hazardous by-products or emissions.
This scope aims to protect the process rather than the compound itself, enabling a focus on manufacturing innovation rather than the molecule of sodium phenylbutyrate, which remains under separate patent regimes or is subject to generic reproduction.
Claims Analysis
1. Independent Claims:
The core of CN116059313 comprises two critical independent claims, which define the process boundaries:
-
Claim 1: Describes a multi-step process including specific reactants, reaction temperatures, solvents, pH conditions, and crystallization parameters to produce sodium phenylbutyrate with high purity.
-
Claim 2: Focuses on an optimized purification and crystallization process that enhances yield and purity, specifying solvent combinations, temperature regimes, and filtration steps.
2. Dependent Claims:
The dependent claims refine Claim 1 and 2, adding specificity such as:
- Using particular catalysts or additives.
- precise molar ratios of reactants.
- particular crystallization parameters (e.g., cooling rates, solvent ratios).
- process steps for residue removal or impurity reduction.
3. Patent Scope Significance:
The claims predominantly emphasize process innovations rather than a new chemical entity, aligning with China's patent standards. They are formulated to prevent replication of a specified manufacturing method, granting BeiGene strong exclusivity over process parameters that yield high-quality SPB.
4. Validity & Enforcement Considerations:
The claims are drafted to withstand novelty and inventive step scrutiny, relying on technical improvements over conventional synthesis routes. Similar processes used outside China may not infringe unless they employ identical or equivalent parameters, giving the patent a moderate to wide scope that hinges on the specificity of the process.
Patent Landscape in China for Sodium Phenylbutyrate
1. Chemical and Pharmaceutical Patent Environment in China
China’s patent system encourages innovation, particularly in pharmaceuticals, via robust patent examination procedures aimed at filtering genuinely inventive processes. The landscape features a significant number of patents related to:
- Chemical synthesis methods of active pharmaceutical ingredients (APIs).
- Formulation patents, including salts and derivatives.
- Manufacturing process improvements to reduce costs and improve safety.
2. Related Patents and Prior Art
Prior art in Chinese and international databases highlights numerous process patents for sodium phenylbutyrate and related compounds. These often focus on:
- Conventional amidation reactions.
- Salting and crystallization techniques.
- Alternative catalysts and solvents.
Compared to these, CN116059313 claims a unique combination of reaction parameters to optimize purity and yield, providing a distinguishable inventive step.
3. Key Competitors and Patent Players
Major players such as BeiGene, WuXi AppTec, and other Chinese biotech firms hold patents covering various synthetic routes and formulations of HDAC inhibitors, including sodium phenylbutyrate. A landscape analysis reveals:
- Innovation shifts toward process efficiency and environmental safety.
- The potential overlap with patents in glycosylation or amidation reactions, common in API synthesis.
- A trend towards process patents that support scalable, commercial production.
4. Patent Family and Continuity
Similar to patent CN116059313, BeiGene and other applicants have filed related applications to enhance patent coverage around manufacturing processes and intermediate compounds, forming a strategic patent family aimed at securing comprehensive protection of SPB production methods in China.
Strategic and Commercial Implications
The patent's scope provides BeiGene with a stronghold on a specific, optimized process for manufacturing sodium phenylbutyrate, a key molecule in anticancer therapies. It creates barriers to entry, especially for generics manufacturers seeking to reproduce or slightly modify existing synthesis routes.
Furthermore, as China fortifies its pharmaceutical patent regime, CN116059313 enhances BeiGene’s patent portfolio footprint, directly impacting:
- Patent infringement risks for companies employing similar methods.
- Potential licensing negotiations for process rights.
- Market exclusivity and strategic positioning in the Chinese oncology drug market.
Conclusion & Key Takeaways
1. Process-Centric Patent Strategy:
CN116059313 underscores China's emphasis on protecting manufacturing processes over chemical entities, offering process patent holders a pragmatic means of securing market exclusivity.
2. Robust Patent Claims:
The claims specify reaction conditions, solvents, purification techniques, and process parameters, contributing to a defendable and specialized patent scope.
3. Key Competitive Edge in China:
BeiGene’s patent fortifies its position in the Chinese market for sodium phenylbutyrate, shaping R&D and licensing strategies for other players.
4. Enforcement and Patent Landscape Navigation:
Given the detailed process claims, legal challenges would likely focus on whether alternative processes infringe or prior art exists. Companies avoiding infringement should innovate around the specified parameters or develop entirely new synthesis routes.
5. Innovation Trend:
The patent exemplifies a broader trend in Chinese pharma patented processes focusing on environmental safety, scale-up potential, and process efficiency, aligning with global manufacturing standards.
FAQ Section
Q1: Can this patent be enforced against foreign companies manufacturing sodium phenylbutyrate outside China?
No. Patent rights are territorial. CN116059313 only provides protection within China. Exporting or manufacturing outside China does not infringe unless the process is directly transferred or employed within China.
Q2: Does this patent protect the chemical structure of sodium phenylbutyrate?
No. It covers the synthesis process, not the molecule itself. The compound's composition is generally protected via separate patents or remains publicly available.
Q3: What are the main advantages of the process disclosed in CN116059313?
Higher yield, improved purity, safer reaction conditions, better scalability, and environmental considerations.
Q4: How does this patent impact generic manufacturers?
It potentially restricts the ability to produce high-quality sodium phenylbutyrate via similar process routes without licensing. Innovators must develop alternative synthesis methods to avoid infringement.
Q5: Are there similar patents globally?
Yes. International patents, especially in the US and Europe, cover sodium phenylbutyrate synthesis, often with different process particulars. Chinese patents like CN116059313 focus on localized innovation, potentially complementing or competing with international patents.
References
- CN116059313: Method for preparing sodium phenylbutyrate and the product thereof. Chinese Patent Office.
- Relevant patent landscapes and prior art disclosures (e.g., WIPO, EPO, USPTO).
- Industry reports on pharmaceutical patent strategies in China.
- BeiGene corporate filings and patent portfolio disclosures.
In summary, CN116059313 embodies a strategic process innovation in sodium phenylbutyrate synthesis, integral to BeiGene’s broader patent and commercial strategy within China's vibrant pharmaceutical landscape.
