How to Protect a Crystal Form (Polymorph) Patent in China

Crystalline forms are critical to pharmaceutical patents, offering extended protection for improved stability, bioavailability, or manufacturability. However, securing such patents in China has grown increasingly difficult due to the China National Intellectual Property Administration (CNIPA)’s strict patentability criteria. Unlike the U.S. or Europe, where structural novelty or problem-solving utility may suffice, China demands quantifiable evidence of superiority over prior art forms and rejects patents based on routine screening alone. Recent decisions, like the invalidation of fruquintinib Crystal Form I, highlight common pitfalls: insufficient comparative data, incremental technical effects, and failures to preempt obviousness challenges. With China’s pharmaceutical market surging and secondary patents under heightened scrutiny, companies must strategically align their IP strategies with CNIPA’s exacting standards to have best chances of success.

A recent invalidation of a patent covering fruquintinib Crystal Form I (Patent No. 201580047368.6) by the CNIPA offers insightful lessons for pharmaceutical companies seeking to protect polymorphs and crystalline forms in China. The decision further confirms China’s rigorous standards for patentability, particularly around support requirements and inventive step.

​Key Takeaways​

​1. Support Requirements Under Article 26.4: Defining “Sufficient Disclosure”​​

The invalidation request argued Claims 1–2 and 6–20 lacked support under Patent Law §26.4, asserting that using only 6–7 XRD peaks (vs. the purported industry standard of 8–10 peaks per evidence 4) failed to sufficiently distinguish "Form I" from undiscovered polymorphs sharing those peaks. The panel rejected this, reasoning that:

​2. Inventive Step Under Article 22.3: The Bar for “Unexpected Effects”​​

The invalidation request contended Claims 1–20 lacked inventiveness under Patent Law §22.3, asserting that Form I of fruquintinib was obvious over evidence1 (disclosing the compound but not its crystal form) combined with routine polymorph screening (per evidence4/5). The panel agreed, reasoning:

  1. ​Obvious Technical Path: Developing stable, non-hygroscopic polymorphs is standard in drug development. Evidence4/5 confirmed solvents and crystallization methods used for Form I were conventional, making its discovery predictable.
  2. ​No Unexpected Effects: While Form I showed stability advantages over other polymorphs (e.g., Form IX in counter evidence1/6), ​no comparison to evidence1’s HMPL-013​ (used in pre-clinical studies) existed. Thus, Form I’s stability/performance could not rebut the presumption of obviousness.
  3. ​Routine Optimization: The panel emphasized that identifying a stable form via routine screening—without unforeseen properties (e.g., radically enhanced bioavailability or unprecedented stability)—did not rise to inventive step.
  4. ​Secondary Considerations: Commercial success claims (counter evidence8) failed to link fruquintinib’s market performance specifically to Form I, undermining non-obviousness arguments.

The decision underscores that mere identification of a new polymorph, absent ​comparative data against the closest prior art form​ or ​unpredicted technical leaps, cannot satisfy inventiveness requirements.

EIP thoughts

It’s generally quite difficult to get granted polymorph claims in China. Standards of patentability that work overseas are often insufficient in China. Applicants wishing to protect formulations, polymorphs, and other “line extension” type IP in China need to proactively adjust their patenting strategies - ideally at the drafting stage - to have a chance of obtaining granted claims in these areas.

​1. Robust Comparison Data​ is Key

​2. File Process Patents

​3. Incorporate China’s Strict Standards into Your Global Patent Strategy​

​So can we patent polymorphs in China?​

The fruquintinib decision clarifies and further confirms China’s patentability standard for polymorph IP. Although in many ways it’s not surprisingly (China has always required data showing surprising technical effect), the requirement that “surprising” data needs to be a direct comparison to known prior art forms raises the bar beyond other jurisdictions.

To prepare, pharma and biotech companies should start early, ideally at the R&D and patent drafting stage, to align “line extension” protection strategies with China’s emphasis on technical effects and comparative data. Meanwhile, companies should continue to explore other ways to round out protection, such as by protecting the processes by which these polymorphs are made.

Companies mapping out “patent cliff” risks for their polymorph patents will need to consider China differently. Polymorph patent with little comparison data support showing superiority over the prior art have a higher chance or being invalidated in China than in foreign jurisdictions.

Still, crystal form patents do get granted and upheld in China, and they can still be part of a powerful portfolio of protective assets if they are drafted in accordance with China’s stricter standards.

​Pro Tip: Engage local IP counsel early to stress-test applications against CNIPA’s evolving standards.

If you would like to have more information on this matter or would like to have our advice, please feel free to contact us at [email protected].

This article is for general informational purposes only and should not be considered legal advice or a legal opinion on a specific set of facts.

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Why Do Examiners Fail to Recognize the Importance of my “Parameter Features”?

The Impact of Parameter Features on Inventiveness

”Parameter features” – numerical or mathematical expressions that define the quantity or physical properties of a subject – frequently appear as technical features within a claim. Often described as numerical ranges or measurements, they frequently play a critical role in addressing technical problems. However, in practice, Examiners and courts often disregard or devalue the inventive contribution of these “parameter features”, leading to considerable confusion among inventors.

Recently, the China National Intellectual Property Administration (CNIPA) released the 2023 Compilation of Key Decisions in Patent Reexamination and Invalidation Cases. Among the cases discussed, two decisions (Cases No. 24 and 25) provide valuable insights into how the parameters of chemical composition and physical properties of a subject influence the determination of inventive step.

Case No.241 (Reexamination Case No. 4W116011)

This case involved a polyurethane polishing pad. The distinguishing technical features between claim 1 and the closest prior art (Evidence 1) were as follows:

  1. The type of curing agent (MCDEA) used was different.
  2. Evidence 1 did not disclose the physical properties of the polyurethane polishing pad.

The central issue was whether the distinguishing technical features (which includes certain parameter features) should be regarded as a whole together with other components of the polyurethane polishing pad. The Reexamination Board determined that distinguishing technical features together with the other components as a whole led to an improvement in planarization and copper recess performance, and such technical effect was supported by experimental data disclosed in the specification.

The Board emphasized that when a claim includes multiple distinguishing technical features—such as chemical composition, concentration, and physical property parameters—an examiner should consider these features holistically from the perspective of a skilled person in the art, and consider whether the claimed features interact synergistically to solve the stated technical problem and achieve an unexpected technical effect.

Despite the fact that parameter features describe “measured” observable characteristics of a structure and composition (as opposed to explicit modifications of such structures or compositions), they should not be dismissed as mere claim limitations (that don’t contribute to the invention). Instead, their technical significance must be objectively examined in light of the disclosure in the specification. In this case, the claim was ultimately upheld.

Case No.251 (Reexamination Case No. 4W115533/4W115534)

This case involved an acidic oil-in-water emulsion liquid seasoning containing sesame. Claim 1 differed from the closest prior art (Evidence 1) in three respects:

  1. pH range was 3.0–4.6.
  2. contained whole sesame seeds (including seed coats) in an amount of 1%–20%.
  3. included sorbic acid, with an acetic acid-to-sorbic acid ratio of 1:0.005 to 1:1.

The Board determined that:

In essence, claim 1 closely resembled evidence 1 in terms of composition, concentration, and technical effect, differing primarily in its use of parameter-based limitations.

The Board emphasized that when a claimed invention is distinguished only by numerical parameters, it is essential that the specification provide experimental data demonstrating that the specific parameter ranges cause the unexpected technical effect. In this case, the specification failed to establish how the claimed parameters influenced the composition, concentration, or performance of the product, and thus could not demonstrate that such parameter limitations produced any significant technical advancement. The claim was ultimately invalidated for lack of inventive step.

EIP Thoughts

The above cases underscore a fundamental principle in Chinese patent practice: the ability of parameter features to contribute to inventiveness hinges on whether the specification includes corresponding experimental data that links the parameter features to one or more unexpected technical effects.

At first glance, ensuring compliance with these requirements during the drafting stage may seem straightforward. However, in practice, achieving this is far more challenging.

How Much Parameter Data is Enough?

It’s one thing to draft and provide strong data demonstrating how certain parameters are linked to an unexpected technical effect. However, applicants may never be able to fully anticipate and prepare sufficient experimental data in advance. After all, it is difficult for an inventor to predict what prior art will arise during prosecution. Regardless of how much data is initially submitted, there is always a risk that different prior art is cited during prosecution, leading to the need for different types of comparison data or supporting evidence.

Additional factors can further contribute to data insufficiency:

Applicants may intentionally withhold certain experimental data to prevent competitors from easily identifying the optimal parameter range from publicly available documents. This may involve disclosing only partial or non-optimal experimental results.

Applicants may deliberately broaden the parameter ranges in their claims to obtain broader protection, even if doing so extends the claim scopes beyond the ranges for which they have robust experimental support.

The Post Filing Data Approach

In such cases, we recommend submitting undisclosed experimental data as “post-filing data” or providing experimental data in a targeted manner during prosecution while carefully adhering to the applicable restrictions2, including:

The specification must describe the technical effect associated with the parameter feature. That is, while the specification may not include explicit experimental data, it must provide a clear assertion of the technical effect produced by the claimed parameter (or range). Without such disclosure, the Examiner will not accept the post-filing data because a person skilled in the art would be unable to verify whether the claimed technical effect is valid based solely on the teachings of the original application.

Post-filing data cannot be used to remedy inherent deficiencies in the original patent application. In other words, such data should only serve as corroborating evidence to substantiate facts that were explicitly or implicitly disclosed in the original specification. It cannot be relied upon to introduce new, previously undisclosed technical effects or to cure an insufficient disclosure in the original application.

Risks of Overly Broad Claims & Best Practices

It is also crucial to highlight the risks associated with claiming overly broad parameter ranges without sufficient experimental support. During prosecution or an invalidation, if a prior art reference discloses any single value within a claimed parameter range, it may anticipate or render the entire range obvious. Without experimental data to support the inventiveness of the claimed parameter ranges, the entire claim will likely fail for lack of inventive step. Expanding the parameter range (without drafting layers of back-up ranges) increases the likelihood that prior art will fall within the claimed scope, ultimately increasing the risk of rejection or invalidation.

To mitigate these risks, we recommend adhering to the following best practices when developing technology and drafting parameter-based claims:

Define parameter ranges as precisely as possible and ensure they are well-supported by experimental data.

Clearly demonstrate a significant technical distinction between the claimed parameter range and the prior art, particularly in terms of unexpected technical effects.

Consider subdividing broad parameter ranges into smaller, well-supported subranges, which enhances flexibility in claim amendments during prosecution.

Ensure that the original application includes sufficient experimental data to support the claimed parameter range and to withstand scrutiny during prosecution and potential invalidation challenges.

By following these strategies, applicants can strengthen the patentability of parameter-based claims and enhance their ability to withstand prosecution and post-grant challenges.

This article is for general informational purposes only and should not be considered legal advice or a legal opinion on a specific set of facts.

  1. https://www.cnipa.gov.cn/module/download/downfile.jsp?classid=0&showname=2023%E5%B9%B4%E5%BA%A6%E4%B8%93%E5%88%A9%E5%A4%8D%E5%AE%A1%E6%97%A0%E6%95%88%E5%85%B8%E5%9E%8B%E6%A1%88%E4%BB%B6%E5%86%B3%E5%AE%9A%E8%A6%81%E7%82%B9%E6%B1%87%E7%BC%96.pdf&filename=bfb092fbe1af43608d88bdc912cd7566.pdf↩︎
  2. https://ipc.court.gov.cn/zh-cn/news/view-3050.html↩︎

Burden Shift: CNIPA Requires Applicant to “Prove” that Post-Filing Data is not Fake Data

“Good Faith” is a challenging concept that brings with it the nuances of a particular jurisdiction’s ideas about honesty, moral values, and societal expectations. Most patent laws around the world include good faith requirements – especially in matters involving the legal and the medical profession – and China is no exception.

So what’s the standard? This case demonstrates one example of how stark inconsistencies between post-filing (clinical trial) data and publicly available information led the CNIPA to reject a case because of false post-filing data submitted in violation of the “good faith” requirement.

Case Background

The disputed patent application, titled “A Type of Tini-Class Small Molecule Compound and Its Preparation Method” from a Tianjin-based drug company claimed a novel pharmaceutical compound having enhanced tolerance and reduced side effects compared to imatinib, a well-known leukemia drug.

In April 2024, the CNIPA rejected the application for insufficiency due to insufficient compound characterization data and experimental data proving the compound’s biological effects.

The applicant requested re-examination and submitted clinical trial data from a comparison study involving 100 patients with chronic myeloid leukemia. However, the CNIPA rejected the case due to severe issues regarding the authenticity of the clinical trial data.

Authenticity of the Clinical Trial Data

Good Faith Requirement in Patent Law:

Article 11 of the Rules for the Implementation of the Patent Law mandates that patent applicants must act in honesty and good faith and refrain from fraudulent or deceptive practices. This principle was introduced in the fourth amendment to the Patent Law to prevent patent abuse and improve patent quality.

Clinical Trial Data Must Be Lawfully Conducted and Publicly Registered

Article 19 of the Drug Administration Law and Article 22 of the Drug Registration Administration Measures require that all clinical trials intended for drug approval must:

These requirements ensure that only legally authorized clinical trials are used to support regulatory approvals, including patents.

In this case, the CNIPA required the applicant to submit real and verifiable experimental data to prove the claimed advantages of the invention.

The applicant claimed to have conducted a clinical trial on 100 patients to compare the safety profile of the new compound against imatinib. However, no record of such a trial was found in the official registration platform, raising concerns about the data’s authenticity.

Data Falsification Determination

The CNIPA concluded that the data was false based on the following logic:

Unregistered Trials are Presumed Illegal

Without proper registration and approval, it would have been impossible for the applicant to conduct a legal human clinical trial under Chinese law.

Reversal of the Burden of Proof

During the re-examination process, CNIPA revered the burden of proof, explicitly requesting that the applicant provide evidence to verify the legitimacy of the clinical data, such as clinical trial approval documentation, patient consent forms, or site agreements with medical institutions. The applicant failed to submit any such documentation, reinforcing the suspicion of data fabrication.

High Probability of False Statements

In the pharmaceutical industry, legally conducted trials always leave a documentary trail, such as third-party laboratory test reports, collaborative agreements with hospitals, or ethics committee approvals. The applicant was unable to produce any of these documents, further confirming the likelihood of data falsification.

Conclusion: Re-examination Request Rejected

Based on the findings, CNIPA concluded that the applicant violated the good faith principle by submitting false and unverified clinical trial data. It also made the following important statements:

As a result, the re-examination request was rejected due to violations of the good faith principle.

Key Takeaways

This case provides valuable lessons for patent applicants, pharmaceutical companies, and IP professionals.

Good Faith is a Fundamental Requirement in Patent Applications

Patent applicants must ensure that all submitted data is truthful, accurate, and legally obtained. Any attempt to misrepresent facts violates the patent system’s integrity and may lead to rejection or even legal consequences.

It’s Important to Have a Good Evidence Chain

All clinical trial data submitted in patent applications should be consistent with other types of data such as publicly available regulatory records, raw experimental data, and third-party verification reports.

Beware of Using Data Not Compliant with Regulatory Laws (or Any Laws)

Understand the Disclosure Requirement for Post Filing Data

It’s important to remember the original rejection under Art. 26.3, where the Examiner reminds us that post-filing supplemental data can be allowed “if the technical effect demonstrated by the supplemental data could undoubtedly be obtained by a skilled person in the art from the disclosure as originally filed.” In this case, even if the false clinical trial data had been real, the original specification still needed to clearly indicate the claimed compound’s surprising effects to ensure that the post-filing data would be acceptable.

EIP Thoughts

This case gives a real-world example of how the good faith standard is applied in patent prosecution, particularly in cases involving human subjects, strict regulatory laws, and ethics requirements. Importantly, the experimental results shown in a patent application must be based on real, and verifiable evidence.

Without reliable evidence (as in this case), the CNIPA will assume that the applicant did not run the trial and thus fabricated the data. Not only is there a violation of good faith, the application itself is not enabled and lacks sufficiency.

In summary, this case serves as a strong reminder for applicants to ensure that the data in their patent applications are obtained in legal ways and supported by strong evidence. Better yet, try to make sure that the data in the patent applications are consistent with published materials. Particularly for highly regulated areas (such as human clinical trials), if there really is no “corroborating evidence” in the public records, the CNIPA can shift the burden of proof and require applicants to prove that the data in the patent application is real and was properly obtained.

This article is for general informational purposes only and should not be considered legal advice or a legal opinion on a specific set of facts.

RNAi Patent Success in China: Overcoming “Comprising” Claim Challenges

An Update on Sufficiency and Inventiveness of RNAi Patents in China

RNAi is a fast-developing technology that has gained traction in the pharmaceutical industry as a promising therapeutic agent. It is important to follow closely RNAi patent proceedings to learn how different examination boards and courts understand and handle these new technologies.

The first-ever invalidation decision in China for an RNAi patent1 was rendered in 2022 by the Patent Re-examination Board (the “Board”). We previously wrote about this case, which discussed the standards for post-filing data, sufficiency, and inventive step, particularly for RNAi inventions. Since then, two newer cases involving RNAi have also been upheld by the Board after facing similar challenges against support and inventiveness. These cases provide further insight into the Board’s standards on examining RNAi patent invalidations.

Quick Recap on the First RNAi Invalidation Decision in China

The invalidation decision concerned a patent claiming Hepatitis B Virus (HBV) RNAi compositions2. The following is a brief recap on the key issues examined in the decision:

Key Issues Examined:

  1. Sufficiency: The petitioner argued that the open-ended term “comprising” in the claims allowed for any nucleotide additions, making the claim scope unclear. The Board dismissed this and emphasized that as long as the primary sequence was intact, a person having ordinary skill in the art (PHOSITA) would understand how to selectively add nucleotides to the primary sequence without compromising the sequence's main function of silencing the HBV gene.
  2. Inventiveness: The petitioner claimed the patented sequences were minor modifications of known HBV RNAi sequences. The Board disagreed, noting that due to the unpredictability in the RNAi field, a PHOSITA would recognise that even minor modifications to the primary sequence could significantly impact the resulting siRNA characteristics.

Ultimately, the Board upheld the patent's validity, concluding that identifying the primary sequence was inventive due to the difficulty in predicting which sequence(s) would have activity. However, once the primary sequence was identified, minor modifications that maintained the integrity of the primary sequence intact were expected to also solve the technical problem. For a detailed analysis of this case, please refer to our previous article here: First ever Invalidation decision on an RNAi Invention patent in China

Later Invalidation Decisions related to RNAi

So what’s happened since then? In China’s 2023 Summaries of 50 Typical Patent Invalidation Cases, two newer cases also involving RNAi were also upheld3 by the Board after facing similar challenges against support and inventiveness. These cases provide further insight into the Board’s standards on examining RNAi patent invalidations.

Background

The patents involve inclisiran, a PSCK9-inhibiting RNAi composition for reducing LDL cholesterol in adult HeFH4 and ASCVD5 patients. The parent patent primarily focuses on claiming the double-stranded RNAi agent, with specific sequences, modifications and conjugations; while the divisional patent has a broader claim scope, covering variations in the RNAi design.

Sufficiency

In both patents, support for claims relating to the RNAi composition conjugated to at least one ligand (parent patent) and conjugated to GalNAc- ligands (divisional patent) were challenged.

The petitioner argued that the specifications only provided data support for the RNAi composition linked to one GalNAc ligand, L96, but did not provide any data to support technical effects of the claimed RNAi composition linked to other ligands.

The Board reinstated that the amount of support needed in a patent specification should be considered in combination with a skilled person’s expectations. Specifically, the technical solution provided by the ligand is directed delivery of the RNAi composition, which is provided relatively independently from the gene-silencing solution of the effective RNAi sequence, such that it is possible to combine varying known ligands with the RNAi component (and still expect successful delivery of the RNAi composition).

The Board believed that a PHOSITA could anticipate the components needed to independently achieve the separate parts of the completed product’s technical solution, such that the complete product could still to solve the presented technical problem. Hence, the Board concluded that the technical solution presented was supported by the specification.

Inventiveness

Regarding the divisional patent, the requester contended that the closest prior art, CN 102458366A6[6], already disclosed highly effective nucleotide regions that could inhibit PCSK9 expression. Therefore, it would be obvious for a PHOSITA to add modifications and ligands to the sequence and design RNAi compositions targeting the PCSK9 gene.

The Board examined the differences between the closest prior art and the claimed invention and highlighted the following differences:

  1. The targeted regions in the unmodified antisense strand sequences are different
  2. The present invention claims modifications for all nucleotides in the RNAi composition, while the closest prior art only claims modifications for some nucleotides
  3. The closest prior art does not include the phosphorothioate modifications in the claimed invention.
  4. The claimed invention depends solely on ligands to deliver the RNAi composition, while the closest prior art uses a lipid formulation, and only in some embodiments in combination with ligands

Moreover, the cited prior art previously “taught away” from the claimed invention, teaching that additional modifications in (2) were not particularly beneficial. The claimed invention also showed higher silencing effect for compositions of the selected primary sequence in combination with specific phosphorothioate modifications of (3). Lastly, the Board indicated that, while use of ligands was disclosed in an examplary embodiment of the closest prior art, the main technical solution of the closest prior art to aid delivery was still the lipid transfection reagent in the composition, and not ligands covalently-linked to the dsRNAi structure.

The Board concluded that, based on the disclosurse in the closest prior art, a PHOSITA would not be motivated to add modifications and ligands to the claimed invention, nor make alterations to the target region sequence. Moreover, the Board affirmed that the technical solution provided was to “provide a RNAi composition of different target sequence, modification and delivery method”, which was different from that of the cloest prior art.

EIP Thoughts

Consistent with the previous case, the conclusions made by the Board were based on the reasonable anticipation of a PHOSITA, which is done by examining the state of the art and the technical problem presented.

Sufficiency

In both cases, the Board upheld claims directed towards a “general” ligand, despite the specification only providing experimental data on one specific ligand L96. These current decisions illustrate the extent to which a broader, more “general” claim scope is possible.

In this instance, the Board reaffirmed that the siRNA and its covalently-linked ligand address different technical problems and are relatively functionally independent. Given that there is a variety of known-in-the-art ligands for directing RNAi delivery, a PHOSITA should be able to “mix-and-match” suitable ligands, and still expect a similar technical effect. Similar to the first invalidation case, the broader claim scope was upheld, based on the notion that the current disclosure is sufficient for a PHOSITA to combine a different ligand to the claimed siRNA, and expect no major compromise on its gene silencing effect.

Inventiveness

The Board’s inventiveness determination consisted of:

  1. identifying the differences in technical effect between the closest prior art and the claimed invention
  2. determining whether the changes applied to achieve those technical effects are obvious or not

Regarding obviousness, it comes down to whether there is motivation for a PHOSITA to make such changes. This is very case-specific and depends on whether teachings of the prior art would cause a PHOSITA to “readily recognize” how a (minor) change could solve the problem.

In this case, the technical differences were examined in detail, with reference to what teachings are available in the prior art. The Board was able to confirm that, in view of the closest prior art, a PHOSITA would not be motivated to add alterations in the primary sequence, make nucleotide modifications and change methods of delivery.

Generally, the RNAi field is considered unpredictable, as it is difficult to predict how a certain composition will react within a living organism.

Can We Get Broader Sequence Claims Now?

Although these cases seem to imply applicants can obtain broader claim scopes without providing as much supporting data (e.g., being able to use “comprising” language), our experience with the CNIPA is not consistent with this decision. In a majority of our prosecution cases, Examiners are still very, very reluctant to grant “comprising” language for sequence listings when there is no data support.

Having said that, these cases were published in the annual list of “50 typical cases”, highlighting representative patent invalidation cases decided by the Board in 2023. Importantly, the Board has affirmed that there is indeed “room” to obtain a generic scope around RNAi inventions that only disclose a handful of species. The cases provide helpful guidance by highlighting the importance of considering the PHOSITA, and how much information (whether prior art knowledge or data in the specification) is needed for a PHOSITA to be “convinced” and “readily recognize” that a different (closely related) species within a generic scope would also work.

We hope examiners and judges alike will refer to these cases when handling RNAi related patent proceedings. In particular, these two cases go into the specifics of RNAi technology, examining technical features beyond just the primary sequence, such as investigating the different modifications to the nucleotides and ligands. As RNAi compositions get more sophisticated and complex, the predictability of each feature behaving a certain way may diminish. This unpredictability could ultimately impact a PHOSITA’s ability to be convinced (without data) that a particular feature works throughout the entire scope of a large genus.

These invalidation proceedings emphasize the importance of considering the specific problem being addressed and the unpredictable nature of certain fields when assessing inventiveness and sufficient disclosure.

This article is for general informational purposes only and should not be considered legal advice or a legal opinion on a specific set of facts.

Can I transfer priority rights in China without the consent of other applicants? Insights from the Broad Institute’s CRISPR patent

The high-profile disputes surrounding an important CRISPR patent belonging to The Broad Institute, MIT and Harvard (hereinafter “the proprietors”) has attracted a lot of attention in recent years, particularly regarding the validity of priority rights that were challenged worldwide. In Europe, the patent was famously revoked by the European Patent Office (hereinafter “EPO”) due to an invalid priority claim1, though recent decisions by EPO suggest a dramatic shift in EPO’s approach that may lead to a different outcome2. Today, we will discuss the decision of the Chinese National Intellectual Property Administration (hereinafter “CNIPA”) in determining whether the proprietors’ priority claims in their CRISPR patent in China were valid, given discrepancies between the applicants in the priority application and the subsequent PCT and Chinese applications. This case brings to light the nuances of claiming priority rights in China and how China’s approach is different from some other countries (Europe and Korea) when it comes to entitlement to priority rights.

Background – claiming priority in China

Priority rights allow an applicant of a patent application to claim the earlier filing date of a previous application (i.e. “priority application”), preventing publications made after the earlier filing date from being used as prior art against the patent application. In China, the CNIPA’s Examination Guidelines (hereinafter “Guidelines”) provide different provisions for the entitlement to claim priority rights under different situations:

  1. National application claiming domestic priority

    For a national application claiming domestic priority, Section 6.2.2.4 in Part I Chapter 1 of the Guidelines states:

    “The applicant of the subsequent application claiming priority shall be the same as that of the previous application. If they are different, the applicant of the subsequent application shall submit a document certifying the assignment of the right of priority signed or sealed by all the applicants of the previous application within 16 months from the earliest priority date.”

  2. National application claiming foreign priority

    For a national application claiming domestic priority, Section 6.2.1.4 in Part I Chapter 1 of the Guidelines states:

    “The applicants of the subsequent application claiming the right of priority shall be the same as the applicant of the previous application, or at least one of the applicants recorded in the certified copy of the previous application document. Where the applicants of the two applications are entirely different, and the right of priority of the previous application has been assigned to the applicant of the subsequent application, a document certifying the assignment of the right of priority, signed or sealed by all of the applicants of the previous application, shall be submitted within 16 months from the earliest priority date.”

  3. National phase entry (NPE) of International Application (PCT) claiming domestic priority

    For NPE of an international application (PCT) claiming foreign priority, the requirements are identical to those of a national application claiming domestic priority, as per Section 5.2.6 in Part III Chapter 1 of the Guidelines.

  4. National phase entry (NPE) of International Application (PCT) claiming foreign priority

    For NPE of an international application (PCT) claiming foreign priority, Section 5.2.3.2 in Part III Chapter 1 of the Guidelines states:

    “Where the earlier application is not filed with the Patent Office, the applicant shall be considered to have right to claim the right of priority if one of the following requirements has been met:

    (1) the applicant of the later application is the same as that of the earlier application;

    (2) the applicant of the later application is one of the applicants of the earlier application;

    (3) the applicant of the later application enjoys the right of priority as the result of assignment or gift of the applicant of the earlier application or transfer of right in other form.”

    For cases under (3), Section 5.2.3.2 further states that “except that the applicant has made a declaration of enjoying the right of priority in the international phase and the declaration meets the requirements, the applicant shall submit the relevant certifying documents. The certifying documents shall be signed or sealed by the assignor(s). The certifying documents shall be the original documents or the certified copy of the original documents.”

It can be observed that the requirements for claiming priority rights are stricter for applications claiming domestic priority compared to those claiming foreign priority, with the national phase entry (NPE) of PCT application claiming foreign priority being the most lenient. The differences in requirements for claiming priority rights under different situations are summarized in the table below:


National Application / NPE of International Application (PCT) claiming domestic priority


National Application claiming foreign priority


NPE of International Application (PCT) claiming foreign priority

Applicant


Same applicant as the previous application(s)


Same applicant or at least one of the applicants of the previous application(s)


Same applicant or at least one of the applicants of the previous application(s)

Formality requirement for the transfer document


signed or sealed by all of the applicants of the previous application(s)


signed or sealed by all of the applicants of the previous application(s)


signed or sealed by the assignor(s)

Relevant sections

Part I Chapter 1 Section 6.2.2.4 (National application)

Part III Chapter 1 Section 5.2.6 (NPE)

Part I Chapter 1 Section 6.2.1.4

Part III Chapter 1 Section 5.2.3.2

Case Facts

The Chinese patent under dispute for this invalidation case is CN201380070567.X, which was filed and granted under the names of The Broad Institute Inc. (hereinafter “Broad”), Massachusetts Institute of Technology (hereinafter “MIT”) and Presidents and Fellows of Harvard College (hereinafter “Harvard”). The Chinese patent was derived from the PCT application no. PCT/US2013/074819, which claims priority from a few US provisional applications. The dispute arose because the proprietors had filed the PCT application (and the subsequent NPE into China) without naming some of the priority applicants (Marraffini Luciano and Habib Naomi) or Marraffini’s successor in title (the Rockefeller University) as the applicants in the PCT application.

This case revolves around a key question: do inconsistencies in applicants between the priority application and the subsequent applications undermine the proprietors’ right to claim priority in China?

A screenshot of a computer screen<br><br>Description automatically generated

PRD’s Decision and Reasoning

The petitioner argued that Part III of the Guidelines, which governs the examination rules for NPE of PCT applications into China, is unclear regarding which provision to apply where the applicants in the previous application and the subsequent application are entirely different, as in this case. It was argued that since priority rights are derived from application rights, priority rights should not be transferred without the consent of all joint applicants.

In its decision, the Patent Re-examination and Invalidation Department (hereinafter “PRD”) of the CNIPA held that:

  1. Entitlement of Priority Rights

    By referring to Part III Chapter 1 Section 5.2.3.2 as discussed above, PRD states that for an international application entering the national phase in China which claims foreign priority, there are 3 scenarios where the applicant(s) shall be considered to have the right to claim priority:

    (1) the applicant of the later application is the same as that of the earlier application;

    (2) the applicant of the later application is one of the applicants of the earlier application;

    (3) the applicant of the later application enjoys the right of priority as the result of assignment or gift of the applicant of the earlier application or transfer of right in other form.”

    The PRD further explained that when the applicant(s) of the later application satisfies the criteria listed in (1) or (2) as the successor(s) in title due to the transfer of rights in (3), they should be able to enjoy the priority rights. Unlike the stricter requirements in applications claiming domestic priority, for NPE of a PCT application which claim foreign priority, it is not required that the applicants (or their successors in title) of the prior application and the subsequent application are completely identical.

    For the present case, as long as the priority rights are properly transferred (under the criterion (3)) from one or more of the applicants of the earlier application (Zhang Feng and Cong Le in this case) to the proprietors (Broad, MIT and Harvard), this will satisfy criterion (2) and the proprietors will be entitled to the right to claim priority.

    This is different from the much stricter approach taken in Europe and South Korea, which requires the applicant of the prior application and the subsequent application to be completely identical in order to enjoy priority rights. If they are not the same, the submission of relevant proof of assignment from all applicants is necessary.

  2. Validity of the Transfer Document

    The petitioners argued that all applicants in the priority application must sign the transfer document to validate the priority claim. The PRD, however, focused on the meaning of “assignor” mentioned in Section 5.2.3.2 (i.e. “the certifying documents shall be signed or sealed by the assignor(s)”), interpreting it more leniently to mean “any assignor” listed as an applicant in the priority application, rather than all co-applicants. In other words, a proof of assignment from all applicants is not necessary.

    Therefore, in the present case, the transfer document signed by Zhang Feng assigning the rights to Broad and MIT, and the transfer document signed by Cong Le assigning the rights to Harvard, validly transfer the priority rights to the proprietors, satisfying criterion (3) in Section 5.2.3.2.

  3. On the Nature of Priority Rights

    The PRD justified its decision by drawing a distinction between priority rights and right of application. It emphasized that while priority rights are significant, they don’t hold the same legal weight as the full right of application. Priority rights are essentially time-based and tied to the novelty determination process. Thus, the PRD reasoned that allowing flexibility in transfer of priority rights, where only one assignor’s consent is needed, does not severely impact the other co-applicants’ rights.

In conclusion, the PRD upheld the proprietors’ priority claim.

Concluding Thoughts: Transferring Priority Rights in China

We believe this case was chosen as a “Top 10 Patent Re-examination and Invalidation case” to illustrate China’s more flexible approach to priority rights (at least for PCT applications entering via national phase), providing foreign applicants more leeway compared to the stricter European and Korean requirements. This flexibility might encourage international applicants to seek patent protection in China, given its comparatively accommodating stance on priority transfers. It will also be interesting to follow the future developments in other jurisdictions on this matter, especially in Europe, which appears to be moving away from its stricter approach to ‘same applicant’ priority.

This article is for general informational purposes only and should not be considered legal advice or a legal opinion on a specific set of facts.

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