In the pharmaceutical field, whether an invention can obtain a patent or remain valid depends not only on the technical quality of the invention itself but also on whether its technical effectiveness can be proven with experimental data. However, due to limitations in the length of application documents or the applicant’s limited understanding of the prior art, it is common in practice to submit supplementary experimental data.

However, under what conditions can the supplementary payment data be accepted? How should the review standards be determined?

This article systematically summarizes the key points for supplementary experimental data review in conjunction with the provisions of the “Patent Examination Guidelines” and typical cases, providing reference for patent practitioners in the pharmaceutical field.

1. Why is it necessary to submit supplementary experimental data?

In the pharmaceutical field, the technical effects of inventions and creations are often difficult to predict based solely on structural deduction. Whether a compound has the expected therapeutic activity, whether the crystal form has superior physicochemical properties, and whether the biological product meets the expected efficacy indicators usually requires experimental data to confirm this.

However, there are two difficulties in patent application practice:

• 1. It is difficult for applicants to predict which prior art the examiner will cite. When filing a patent application, applicants do not know exactly which document the future examiner or invalidator will select as the closest prior art, so it is not possible to specifically preset comparative experiments in the application documents.
• 2. The length and focus of application documents are limited. Application documents cannot exhaust all possible comparative experiments; they often focus on verifying the technical effects of the invention itself rather than cross-sectional comparisons with various prior art.

The resulting issue is: during examination or invalidation procedures, after a prior art comparison document is submitted, can the applicant or patent holder submit experimental data completed after the filing date to prove that their invention has better technical effects compared to the prior art? This issue has long been a focal point of confusion in patent practice in the pharmaceutical field.

2. Legal Basis

for Supplementary Submission of Experimental Data The core basis for the review of supplementary submission of experimental data comes from two levels:
at the departmental regulatory level, Section 3.5.1 of Chapter 10, Part II of the Patent Examination Guidelines stipulatesFor experimental data supplemented after the application date, the examiner shall examine them, but the technical effects proven by the supplementary data must be something that skilled practitioners in the art can obtain from the content disclosed in the patent application.

At the judicial level, Article 10 of the “Provisions of the Supreme People’s Court on Several Issues Concerning the Application of Law in the Trial of Administrative Cases of Patent Authorization and Confirmation” further clarifies that if a drug patent applicant submits supplementary experimental data after the application date, the people’s court shall review it.
The reason these regulations allow supplementary experimental data is to balance the two fundamental principles of the Patent Law: the “first-to-file” system and the “public for protection” principles.
The first-to-file system requires applicants to submit their applications as early as possible, while the open-for-protection principle requires full disclosure of technical effects. There is an inherent tension between the two—applicants find it difficult to exhaust all verification experiments at the time of application, nor can they predict which prior art reviewers will cite in the future. The system for supplementary experimental data is precisely a compromise sought under this tension, and its review standards have always revolved around this balance.

3. Key Review Points

for Supplementary Experimental Data (1) Review Point One: Availability of
Technical Effects “The availability of technical effects” is the most critical review point in reviewing supplementary experimental data. This is also the primary threshold for judging whether the supplementary data can be accepted.
The first step in examination is to determine which technical effects can be inferred from the content disclosed in the patent application. This must be based on the original specification and the content recorded in the claims.
Specifically, the following situations exist:

• First, the results are consistent or specifically reflected. If the technical effects demonstrated by the supplementary data are consistent with those obtained from the original public content, or if the latter is specifically reflected under different testing conditions, the supplementary data can be included as a factual basis for review.
• Second, the extension from general formula compounds to specific compounds. If the original application documents record the technical effects of a general formula compound, supplementary data is provided to prove that the specific compound has such technical effects. As long as the original application provides reasonable technical guidance and the skilled personnel in the art can reasonably believe it, it is generally acceptable.

Third, there is a lack of broad descriptions of specific technical directions. If the original application only records broad expected effects without specific technical indications, then the technical effects demonstrated by supplementary data lack factual basis in the patent application and are difficult to accept.

(2) Review Point 2: Authenticity and relevance of experimental data.
Even if the effects demonstrated by supplementary data can be derived from the original public content, their inherent quality must still be reviewed. The core of this dimension is “method comparability” and “data trustworthiness.”
Method correspondence is the primary criterion. The experimental methods and conditions used for supplementary experimental data should be consistent with the experimental scheme described in the original application specification, or be a conventional validation method in the field, and should be able to be reasonably compared with the existing art. If the experimental method used in the supplementary data differs from that of the closest approach to the existing art, the resulting data will not be accepted due to lack of comparability. It is especially important to note that data from different experimental sources, regardless of how they are converted, cannot be used as a basis for determining technical effectiveness; Conversion should be performed within the same experiment; cross-experiment conversion does not conform to conventional understanding in this field.
The authenticity of the data itself is fundamental. Experimental data must be authentic, accurate, and traceable. Clearly and completely recording the experimental process, results from each batch, and data processing procedures. The results can be cross-verified, which is an important condition for supplementary experimental data to be accepted. In review practice, the collegial panel usually rigorously examines supplementary experimental data from aspects such as the experimental content itself, the experimental process, and the conclusion. Common areas of concern include: whether there are discrepancies between experimental results and original records that provide a reasonable explanation, whether there are contradictions between different batches of data, and whether data processing methods conform to industry practices.

(3) Review Point Three: Distinguishing
the Purpose of Proof Supplementary Submission of Experimental Data There are important differences in review standards under the two situations of “sufficient disclosure of the proof specification” and “proof of inventiveness.” This distinction is easily overlooked in practice, but it directly affects the choice of argument strategy.
When the specification is fully disclosed, the focus of review is whether the supplementary data can prove that “the technical personnel in the art have achieved the technical effect before the application date.” The supplementary data cannot be used to compensate for the substantive defect of the original specification being “not sufficiently disclosed.” If the original application document itself has insufficient disclosure defects, it cannot be remedied by post-submission of data.
When proving inventiveness, the focus of review is whether the supplementary data demonstrates “unexpected technical effects compared to the comparative documents.” As long as the effect is asserted in the original application and the supplementary data provides reasonable supporting evidence, it can be considered in the inventive judgment. The Supreme People’s Court has established a “reasonable certainty” criterion in relevant precedents—that is, it does not require supplementary data to exist before the application date, but rather examines whether technical personnel in the art can reasonably believe in the existence and degree of the technical effect based on the original disclosed content. This benchmark further relaxes the acceptance criteria for supplementary experimental data in creative judgments, clearly distinguishing it from fully disclosed review standards.

(4) Key Examination Point Four: Balancing interests and good faith
The admissibility of supplementary experimental data is ultimately governed by a baseline principle: the supplementary data cannot provide the patent holder with protection beyond the scope of their actual technical contribution.
First, it is not allowed to make up for any unfinished experimental defects after the fact. It is not possible to make up for the experimental validation left unfinished at the time of application by submitting supplementary data “after the fact,” thereby improperly occupying prior art or public knowledge that should have belonged to the public at the time of the application date.
Second, no new technical content should be introduced. The supplementary data cannot be used to cover up inherent defects in the original application documents, nor can it be used to introduce new technical content not disclosed at the time of application. In examination practice, the collegial panel usually conducts the review according to the steps of “what effects can be inferred from the patent application disclosure—what effects are proven by supplementary experimental data—whether a connection can be established between the two,” ensuring that supplementary data does not exceed the scope of the original disclosure.
It should be noted that this dimension is intrinsically related to the “availability of technical effects,” but the focus differs: the former focuses on the technical level of “whether it can be obtained from the original disclosure,” while the latter focuses on the institutional level of “whether it exceeds actual technical contributions.” Together, they form the institutional boundary for supplementary experimental data review.

4. Typical Case: The four key points of review mentioned above in

the crizotinib crystal-type patent invalidation case are concentrated in the crizotinib crystal-type patent invalidation case. The case was reviewed by the National Intellectual Property Administration in Decision No. 581892, maintaining the validity of the patent based on the authorized announcement text. The following is a detailed demonstration of the identification process of supplementary experimental data in different scenarios in conjunction with this case.

(1) Case Background and Key Points

of Dispute Crizotinib is the world’s first multi-gene first-line therapy targeting ALK “diamond mutations,” approved for market in China in 2013. The patent involved in this case is the “Polycrystalline Form of C-MET/HGFR Inhibitor” (Patent No.: ZL200680045883.1), whose claim 1 protects a specific crystalline form of crizotinib and characterizes it using powder X-ray diffraction spectraform.
The petitioner, Jiangsu Wanbang Biochemical Pharmaceutical Group Co., Ltd., requested to declare the patent invalid on the grounds of lack of inventiveness. In the judgment of inventiveness, the closest prior art is Evidence 8—the patentee’s prior invention, which discloses a general formula compound with c-Met inhibitor activity and specifically lists a large number of compounds including compound I-426 and their activity data.
Therefore, the core dispute in this case is: Has the crizotinib crystal form of this patent achieved unexpected technical effects compared to compound I-426 in Evidence 8? Around this issue, both sides debated the admissibility of submitting multiple supplementary experimental data.

(2) Identification Process

of Three Supplementary Experimental Data This patent specification cites prior patent applications in the background art, which records c-Met inhibitory activity data for crizotinib free alkali (Ki=0.003μM). This data has been disclosed in the original application documents and can serve as the factual basis for determining the technical effect, with no dispute among the parties.
The petitioner submitted Evidence 14 and Evidence 15, both journal documents published after the application date, which recorded crizotinib’s IC50 data to demonstrate that the technical effects of crizotinib did not exceed expectations.
After review, the collegial panel determined that:

• The IC50 data in Evidence 14 were measured using the time-resolution-fluorescence resonance energy transfer method, which differs in both experimental principle and conditions from the Met-phosphorylated cell assay method used in Evidence 8;
• The IC50 data in Evidence 15 were obtained using the ELISA method, and the experimental results are averages across a set of cell lines, differing from the Met-phosphorylated cell assay method used in Evidence 8 using the A549 cell line.
• Due to differences in experimental methods, the above data are not comparable to the data closest to the prior art and are therefore not adopted.

(3) The comparative experiment re-completed in the invalidation procedure directly compared the activity of the patented compound and Evidence 8’s compound I-426. The patentee redesigned and completed the comparative experiment (Counter-Evidence 22), using the same two experimental protocols as in Evidence 8: HGFR continuous coupled spectrophotometry and Met-phosphorylated cell assay.

The results of Counter-evidence 22 show:

• Using HGFR continuous coupled spectrophotometry, crizotinib’s Ki value improved by two orders of magnitude compared to compound I-426, which is basically consistent with the citation documents and evidence 15;
• Using the Met-phosphorylation cell assay, crizotinib’s IC50 is an order of magnitude higher than that of compound I-426.

One reason for questioning the authenticity of this experiment is that the results of the Met-phosphorylated cell test differ from the original records in Evidence 8. In response, the patentee explained: The experimental method for Evidence 8 is relatively early, while Counterevidence 22 uses the standard methods commonly used in the art, combined with the same cell lines and treatment conditions as Evidence 8, making the experimental results more accurate and reliable.
The panel held that Counter-Evidence 22 clearly and completely records the experimental process, the results of each batch, and the data processing procedures. The experimental results can mutually corroborate each other, and the patentee’s interpretation is reasonable. Those skilled in the art have no reason to doubt its reasonableness or authenticity. Ultimately, the panel adopted the comparative experimental results of the continuous coupled spectrophotometry method in Counter-Evidence 22 as the basis for determining differences in technical effects, and accordingly confirmed that the patent possesses inventiveness and maintains the validity of the patent rights.

(4) Case Insights

The crizotinib case clearly presents the different fate of supplementary experimental data under various scenarios, providing comprehensive verification of the four key review points mentioned above:
the availability of technical effects. The effect demonstrated by Counterevidence 22—crizotinib has superior c-Met inhibitory activity compared to Evidence 8—is already indicated by data from Ki=0.003μM in the original cited document, which is not “fabricated out of thin air.” The panel confirmed that this effect could be obtained from the original public content based on the consistency between the original data and the results of Counter-Evidence 22.
Authenticity and relevance. Evidence 14 and 15 were rejected due to differences in experimental methods, while Counterevidence 22 was adopted for using the same method as Evidence 8—the stark contrast reveals the decisive role of method correspondence. Evidence 22 withstands scrutiny largely because it fully records the experimental process, batch results, and data processing, and the results can corrogate each other.
Distinction of proof purposes. In this case, in the context of inventive judgment, the supplementary experimental data was discussed. The collegial panel did not require that the data of Counter-Evidence 22 existed before the application date, but instead focused on examining whether it could prove “unexpected technical effects compared to the technology closest to the prior art,” reflecting the applicability of the “reasonable confidence” criterion.
Balancing interests and honesty and trustworthiness. The collegial panel adopted Counter-Evidence 22 on the premise that the effect of the data proof did not exceed the scope of the original disclosed content, nor did it provide the patent holder with protection beyond their actual technical contribution.

IV. Practical Recommendations

for Applicants Based on the above review points, the following practical suggestions are proposed:
First, application writing is fundamental. The specification is the foundation of a patent. Technical effects should be recorded as clearly and completely as possible in the original application documents. At the very least, the effect should be clearly described, the method used, and the results obtained. Supplementing experimental data is a “remedy” rather than a “universal patch” and cannot save an application that is already flawed.
Second, comparability of experimental methods is key. If the most recent prior art is known or reasonably foreseeable, try to use experimental methods identical or comparable to that prior art to leave direct evidence for subsequent comparison. For supplementary data to be adopted, comparability of experimental methods is the primary criterion.
Third, distinguish between different purposes of proof. There are differences in review standards between those used to prove full disclosure and those used to prove creativity. In inventive judgment, the “reasonable conviction” criterion can be used to argue.
Fourth, record the entire experimental process. When supplementing experimental data, the experimental process, results of each batch, and data processing methods should be clearly and completely recorded to ensure it can withstand questioning from the opposing party and the collegial panel.

5. Conclusion

Facing increasingly stringent examination standards, applicants should abandon the “take the slot first, supplement the data later” mentality and prioritize technical effectiveness verification. During the writing stage, it is essential to clearly and completely record experimental methods and effect data to reserve a solid factual basis for possible subsequent supplementary submissions.

When dealing with review or invalidation procedures, strict control must be taken to ensure the comparability and authenticity of data methods, and to accurately distinguish the purpose of proof. Only by deeply integrating compliant patent layout with rigorous experimental management can a moat be built in the fierce competition for pharmaceutical intellectual property.

MeritsIP: Your Global Intellectual Property Partner

At MeritsIP, we provide comprehensive IP services in biomedicine, medical devices, manufacturing, semiconductors, and AI. We support 200+ top clients globally with strategic, high-quality IP services.

Stay Connected

• • Website: https://www.meritsipglobal.com

• • LinkedIn: Follow us on LinkedIn

• • Email: meritsip@meritsandtree.com

© 2025 MeritsIP. All Rights Reserved.