CHANG TSI
Insights
In the first article of this series, we elaborated on the regulatory framework of the Pharmaceuticals patent linkage system of China, along with the current status of case acceptance, applicable conditions, and procedural frameworks. This article turns to emerging judicial rules and practical issues, analyzing how courts and administrative bodies have applied the patent linkage system in actual cases that have been published. Based on the author’s experience with such cases, the article offers insights to help practitioners address common challenges.
Under China’s current patent linkage framework, not all types of drug-related patents are eligible for registration or can serve as the basis for initiating a linkage dispute. Among the more complex issues is how to determine whether a patent is crystalline form patent and whether it falls within the registrable scope. However, in the absence of specific and clearly defined provisions, there may be different interpretations in practice regarding what constitutes a crystalline form patent and whether use patent for a crystalline form fall within the scope of registrable patents.
1. Relevant Laws and Regulations
Article 5 of the Measures for the Implementation of the Early Resolution Mechanism for Drug Patent Disputes (hereinafter, the “Measures for the Implementation”) allows a marketing authorization holder (“MAH”) to register patents on: (i) compound inventions of active pharmaceutical ingredients, (ii) pharmaceutical compositions containing such active ingredients, and (iii) medical use patents of the active ingredients.
The Policy Interpretation of the Measures for the Implementation (hereinafter, the “Policy Interpretation”) jointly issued by the National Medical Products Administration (“NMPA”) and the China National Intellectual Property Administration (“CNIPA”) further clarifies that patents including intermediates, metabolites, crystalline forms, preparation methods, and testing methods are not registrable.
However, the Measures for the Implementation its Policy Interpretation do not specify how to identify a crystalline form patent, nor do they clarify whether use patents use patent for crystalline forms qualify as registrable patents.
2. Relevant Judicial Principles in Practice
From publicly available administrative and judicial decisions, two main principles have emerged:
(1) Whether a patent constitutes a crystalline form patent should be determined based on the subject matter and technical features of the claims. If the claims do not refer to crystalline characteristics, or lack terminology or characterization specific to crystalline forms (e.g., X-ray powder diffraction peaks), courts should not expansively interpret such claims as covering crystalline forms. ( (2021) CNIPA YaoCai No. 0009; (2021) CNIPA YaoCai No.0010; (2021) CNIPA YaoCai No. 0011)
(2) The “medical use patents” referred to in Article 5 of the Measures for the Implementation cover uses of active compound patents or composition patents, but not pharmaceutical-use claims limited to a crystalline form. The latter fall under the category of crystalline form patents and thus cannot be registered as “use patents” under the linkage framework. ((2022) CNIPA YaoCai No.0015; (2023) SPC ZhiMinZhong No.7)
In the judgement, the Supreme People’s Court (“SPC”) has emphasized, through literal interpretation of the Measures for the Implementation and policy considerations, that the early resolution mechanism is not the exclusive forum for resolving such disputes. Accordingly, courts have taken a restrictive approach to the scope of registrable patents. We believe this approach aligns with the legislative intent, which is to prevent overly broad protection and to strike a balance between protecting original drug patents and promoting timely market entry of generics.
1. Relevant Laws and Regulations
Under Article 6 of the Measures for the Implementation, where no relevant patent information is listed on the NMPA’s patent registration platform, a generic applicant must make a Category 1 Declaration. As noted in Part I of this series, a Category 1 Declaration generally does not trigger the early resolution mechanism unless the declaration itself contains an error.
2. Relevant Judicial Principles in Practice
A recurring question concerns whether applicants for Category III chemical drug, that is, domestic generics of drugs already approved overseas but not yet marketed in China, may directly make a Category 1 Declaration. Both administrative and judicial decisions have addressed this issue.
First, if the dosage form of the generic drug differs from that of the original drug marketed in China, the registered patents of the original drug are not “relevant patents” within the meaning of Article 76 of the Patent Law. In such cases, a Category 1 Declaration is legally permissible. ((2023) SPC ZhiMinZhong No.1233)
However, when the only difference between the generic drug seeking marketing approval and the original drug already approved lies in dosage strength, the analysis changes. Under the current regulatory framework, generics of the same dosage form may select a reference listed drug (“RLD”) of a different strength and submit data demonstrating equivalent quality and efficacy to support their registration. That said, given the purpose of the patent linkage system and the public interest it seeks to protect, even though chemical drugs of different strengths must be separately registered and obtain independent approval numbers under drug administration rules, if another strength of the RLD has already been listed with patent information on the registration platform, a generic applicant’s Category 1 Declaration aimed at avoiding the early resolution mechanism will generally not be upheld by the courts. In such cases, a generic applicant is, as a matter of principle, expected to make its patent declaration with reference to the patents registered under other strengths of the same RLD. ( (2023) SPC ZhiMinZhong No.1233; (2021) CNIPA YaoCai No.0018; (2021) CNIPA YaoCai No.0019)
A. Time limit for Filing the litigation/administrative adjudication
1. Relevant Laws and Regulations
Under Article 7 of the Measures for the Implementation, a patentee or interested party may, within 45 days from the NMPA’s public disclosure of a generic drug application, file a civil lawsuit with a people’s court or request an administrative adjudication from the CNIPA to determine whether the generic’s technical solution falls within the patent’s protection scope.
2. Relevant Judicial Principles in Practice
A practical question arises: Can a patent linkage case still be filed after the 45-day period expires? To date, no published judgement has directly addressed this issue. However, the prevailing view in practice is that the 45-day period should not be treated as a mandatory condition for case acceptance.
First, neither the Patent Law, the Provisions of the Supreme People’s Court on Several Issues Concerning the Application of Law in the Trial of Civil Cases of Patent Right Disputes Related to Drug Registration Application (hereinafter, the “Judicial Interpretation on Civil Cases of Drug Patent Disputes”) imposes a statutory 45-day filing deadline. Second, as a set of departmental rules, the Measures for the Implementation should not serve as a mandatory jurisdictional basis unless expressly incorporated by higher-level law or judicial interpretation. (Rui Songyan, 2024) Moreover, Article 7 of the Measures for the Implementation uses permissive rather than mandatory language, “may, within 45 days”, which supports a discretionary interpretation.
The NMPA and CNIPA’s Policy Interpretation also provides helpful context. It explains that if a lawsuit or adjudication request is filed within 45 days, and the acceptance notice is submitted to the CDE within 15 days after acceptance, the CDE will impose a nine-month stay period.
This indicates that the 45‑day period may operate primarily as a condition for triggering the stay, rather than as a mandatory filing deadline.
Accordingly, treating the 45-day window as jurisdictional could unjustly deprive patent holders of the opportunity to protect their rights under the linkage system, which is contrary to the system’s intended purpose. Nevertheless, judicial and administrative authorities may differ in practice. Based on our case-handling experience, courts have generally taken a flexible approach to this time limit when accepting and hearing cases. We will continue to monitor relevant judgments and administrative adjudications, and share our further insights.
For generic applicants, it is worth noting that Article 4 of the Judicial Interpretation on Civil Cases of Drug Patent Disputes allows a generic applicant to file a lawsuit for a declaration of non-infringement if the patent holder or interested party fails to act within 45 days. This 45-day rule, therefore, is widely regarded as a condition precedent for a generic applicant’s right to bring such a suit. (Rui Songyan, 2024)
B. Time Limit for Patent Information Registration by the MAH
1. Relevant Laws and Regulations
According to Article 4 of the Measures for the Implementation, the MAH must register the relevant patent information within 30 days after obtaining the drug registration certificate.
2. Relevant Judicial Principles in Practice
In practice, a potentially contentious issue arises when a generic applicant makes a Category 1 Declaration before the MAH completes patent registration: would such timing affect the admissibility of a patent linkage case? The following scenarios illustrate possible outcomes.
Scenario 1: The MAH completes patent registration within the prescribed 30-day period, but the registration or public disclosure of the patent occurs after the generic applicant has made its patent declaration.
Neither the Patent Law nor the Measures for the Implementation imposes restrictions on the sequence between patent registration by the originator and application filing by the generic. In practice, a generic applicant may file its declaration before the MAH has registered the relevant patent. When no patent information is available on the platform at that time, the generic applicant can only make a Category 1 Declaration. As a result, the formal requirements for initiating a patent linkage proceeding appear not to be met, even though neither party is at fault.
The patent linkage system aims to resolve potential patent disputes before the generic drug enters the market, rather than after approval. Viewed in this light, the mere order of registration should not prevent the filing of a lawsuit or administrative adjudication request, especially when the MAH has completed registration within the prescribed 30-day period.
The SPC has clarified that where the MAH has correctly registered patent information within the required timeframe, it should be afforded a reasonable opportunity to request the generic applicant to amend its declaration category. If the generic applicant subsequently changes its Category 1 Declaration to a Category 4 Declaration, refuses to amend within a reasonable period, or amends it incorrectly, the court should accept the patentee’s linkage lawsuit for substantive review. ((2023) SPC ZhiMinZhong No.1593)
It is worth noting that, based on the our experience in practice, there are currently no available channels or regulatory provisions that permit a generic drug applicant to change the category of its declaration. As a result, claims, whether brought in administrative adjudication or in litigation, that seek to compel a generic drug applicant to change the declaration category are unlikely to be upheld by either the CNIPA or the courts. From the author’s perspective, the principal rationale behind requiring a generic drug applicant to amend its declaration category is to satisfy, at least in formal terms, the conditions for bringing a pharmaceutical patent linkage action. However, according to the underlying principles reflected in judgements of the SPC, where a court has accepted and substantively heard a case, changing the declaration category during the acceptance or trial stage has little practical effect. Ultimately, the declaration category may need to be amended in line with the court’s judgment so that it matches the actual circumstances.
Scenario 2: The MAH fails to complete patent registration within the 30-day period.
In Scenario 1, the MAH’s registration occurred after the generic applicant’s declaration but still within the 30-day window. A different situation arises when the MAH fails to register the patent within 30 days, while the generic applicant has already made a Category 1 Declaration. Unlike in Scenario 1, the MAH in this case has missed the statutory deadline.
This may occur for various reasons. Since patent examination and drug marketing authorization are separate procedures with distinct timelines, a relevant patent may be granted after drug approval, making it impossible for the MAH to complete registration within 30 days. At present, no judicial or administrative precedent provides clear guidance on how to handle such cases.
In our view, where the MAH, patentee, or other interested party is objectively unable to complete patent registration within the prescribed period, denying their access to the early resolution mechanism would contradict the purpose of the patent linkage system and create a practical loophole. In the absence of an explicit legal requirement that registration within 30 days is a prerequisite for case acceptance, we believe that courts and the CNIPA should, in principle, accept and substantively review such cases, provided that the MAH has completed registration without apparent fault. Going forward, it is expected that judicial practice will provide more explicit guidance on how to address such timing conflicts under the current framework.
C. Relevance of Registered Patents
The early resolution mechanism for pharmaceutical patent disputes requires not only that the MAH of an original drug register, on the registration platform, patents that relate to the original drug, but also that the technical solution of the original drug falls within the protection scope of the claims of such patents.
In judgment (2023) SPC ZhiMinZhong No.2 and (2023) SPC ZhiMinZhong 3, the SPC held: “Only where the technical solution of the original drug itself falls within the protection scope of the relevant patent claims can an action brought by the patentee or an interested party be recognized as having the legal basis provided under Article 76, Paragraph 1 of the Patent Law.” In these two judgments, the SPC further observed that the registration information for patents associated with an original drug should include a clear correspondence between the original drug and the relevant patent claims. Where the technical solution of the original drug does not fall within the protection scope of the patent claims asserted by the patentee or interested party, the SPC will dismiss the lawsuit.
The CNIPA has likewise addressed the issue of patent registration in administrative adjudications. It stated that the patent information registered by the MAH must be truthful and accurate, and that the protection scope of the patents concerned should cover the corresponding technical solution of the approved drug. However, this requirement merely calls for the technical solution of the original drug to be within the protection scope of the registered patent; it does not require that the inventive step of the patent be explicitly reflected in the application materials for the original drug. ( (2021) CNIPA YaoCai No.0023)
1. Obligation of Generic Drug Applicants to Establish that Their Technical Solution Falls Outside the Patent Scope
Article 6 of the Measures for the Implication require that when filing a marketing authorization application for a chemical generic drug, the applicant must not only submit a patent-related declaration, but also serve that declaration and supporting grounds on the MAH for the RLD (original drug).
For a Category 4.2 declaration, the supporting grounds must include a claim chart comparing the generic drug’s technical solution with the relevant patent’s claims, together with related technical documentation. Article 7 of the Measures for Administrative Adjudication of the Early Resolution Mechanism for Drug Patent Disputes (hereinafter, the Measures for Administrative Adjudication) further provides that a generic drug applicant requesting an administrative adjudication must submit the technical solution for the drug in question to enable the court or the CNIPA to determine whether the product falls within the scope of patent protection.
From a structural standpoint, these provisions impose an initial evidentiary burden at the statement stage: the applicant must submit factual and technical bases supporting the statement. This burden allocation reflects that a generic drug applicant, as both the filer of the marketing authorization application and the declarant, is effectively asserting a position. Under the fundamental civil procedure principle of “he who asserts must prove,” the applicant must, within the period designated, produce its technical solution whether it is the petitioner or respondent in the administrative adjudication. Failing to do so invites adverse evidentiary consequences.
In practice, given that generics typically match the original drug in active ingredient, therapeutic effect, and dosage form, there is a prima facie likelihood that the generic’s technical solution overlaps with the patent scope. The registration dossier is uniquely within the applicant’s possession, making it the party best able, and obliged, to provide the technical solution establishing non‑infringement.
In (2023) CNIPA YaoCai No. 0055 and (2024) CNIPA YaoCai No. 0014, the CNIPA emphasized that this disclosure obligation stems from the nature of patent linkage disputes. The obligation does not depend on whether the generic drug applicant is a requesting or responding party, nor on whether it has filed a Category 4.1 or 4.2 declaration. In all cases, the applicant must submit, within the panel’s designated timeframe, the technical solution and supporting evidence justifying its statement.
Confidentiality concerns do not negate the burden: Article 7 of the Measures for Administrative Adjudication specifically requires applicants to submit the technical solution along with a confidentiality designation if the materials contain sensitive information.
2. Evidence Must Address All Technical Features of the Asserted Patent
Article 7 Paragraph 1 of the Provisions of the Supreme People’s Court on Several Issues Concerning the Application of Law in the Trial of Civil Cases of Patent Right Disputes Related to Drug Registration Application requires courts to examine all technical features recited in each asserted patent claim when determining whether the accused technology falls within the patent scope. Chapter V of the CNIPA’s Patent Infringement Administrative Adjudication Guidelines also affirms this principle of full coverage.
Accordingly, in patent linkage litigation or administrative adjudication, a generic drug applicant’s proof must map its technical solution to all of the claim’s technical features. If the generic drug applicant is able to submit such evidence but fails to do so within the designated period, and its approval materials likely contain the relevant information, it risks bearing the adverse evidentiary consequences. ( (2021) CNIPA YaoCai No. 0023)
3. Burden of Proof Limited to Showing High Likelihood of Falling Within or Outside the Patent Scope
Although the generic applicant bears the burden of proof, it is not limitless. Based on available administrative adjudications, the required showing is confined to demonstrating a high likelihood either that the technical solution falls within, or does not fall within, the patent scope. ( (2022) CNIPA YaoCai No. 0016)
Because patent linkage proceedings differ from post-marketing patent infringement proceedings, courts and administrative bodies have, in practice, avoided wholesale adoption of the evidentiary standards applied in infringement cases. Full adoption of those standards is viewed as likely to unduly increase the burden of proof on the generic applicant and to disrupt the balance of interests between originator drug holders and generic manufacturers. ((2021) CNIPA YaoCai No. 0023)
4. Challenges to Patent Registration Accuracy
Under the Measures for the Implementation, the MAH for the original drug is responsible for the truthfulness, accuracy, and completeness of registered patent information. The registration platform conducts only formal examination, and CNIPA will not sua sponte assess whether the registered patent actually covers the originator’s technical solution.
Thus, if a generic applicant disputes the accuracy of the registration, it must provide evidence or a reasoned explanation creating genuine doubt. The panel will then consider the defense. ((2022) CNIPA YaoCai No. 0011)
In judgement (2023) SPC ZhiMinZhong No. 2, the SPC held that where the parties dispute whether the originator’s technical solution falls within the patent scope, the court must examine this issue at trial. In (2024) SPC ZhiXingZhong No. 88, the SPC further held that in patent linkage litigation, a generic applicant asserting that the originator’s technical solution does not fall within the patent scope must first prove or substantiate its position. It may not simply demand that the patentee or originator MAH disclose, or request the court to compel production of, the originator’s marketing authorization dossier.
It has been only four years since Article 76 of the Patent Law came into effect, and many practical issues surrounding civil litigation and administrative adjudication in the patent linkage disputes remain in need of exploration and clarification. We hope that the observations and summaries in this article will not only provide a useful reference for readers, but also inspire further discussion and reflection. We also look forward to the emergence of more representative cases and authoritative guidance in the future, to promote a more efficient and transparent operation of the system.
