TAI Hong, GUO Yu, WEI Jie, CHEN Kan

Prologue

In the field of medicine, the research and development of innovative drugs often require a large amount of capital and human resources. It often takes billions of dollars of investment and years of experimentation and examination before the drugs can finally be marketed. Thus, innovative drugs belong to a special field highly dependent on intellectual property protection. Only by strengthening the protection of intellectual property rights, especially the protection of medicine-related patents, can we continue to promote the development of more and more innovative drugs, thereby helping to ensure the life and health interests of the people.

The core of innovative drugs showing excellent therapeutic effects lies in the pharmaceutically active ingredients of the drugs, such as the active compounds in chemical drugs. The screening of pharmaceutically active compounds is the initial stage in the development of innovative drugs and is also one of the stages with the most time and money invested in research and development. It can be said that pharmaceutically active compounds are the core of the medicine. Without the discovery of new compounds, there will be no innovative drugs. Correspondingly, compound patents are also the initial stage patents in pharmaceutical patents, and they are also the core of pharmaceutical patents.

At the same time, patent disputes in the medical field are also increasing. The number of invalidation requests against compound patents as the core patents is also increasing. According to statistics, 34.29% of compound patents have been declared invalid in the past 10 years, which is higher than that of the major markets such as Europe and the United States. In addition, among all the cases declaring the patents invalid in their entirety, most of the cases declared the patents invalid because the compound patents lack inventiveness.

To this end, this project firstly conducts statistical analysis on the current status of compound patents’ invalidity declaration examination and administrative litigations for invalidation disputes in China in the past 10 years. This project incorporates European and American practices, and mainly conducts comparative analysis on the lead compound issues in the compound inventiveness issues, the issue regarding motivation and teaching for structural modification, and the issue regarding supplementary experimental data, and provides corresponding suggestions to be considered by those in the field.

Part I  Statistical Analysis of Compound Patents Invalidation in China

This part first conducts search and statistical analysis on compound patents invalidity declaration examination and administrative litigations for invalidation disputes in China.

1. Methods of Searching and Analyzing Invalidation Cases

In the “Oral Examination Announcement and Decision Inquiry” system on the homepage of the Patent Reexamination and Invalidation Department of China National Intellectual Property Administration (“CNIPA”), the International Classification Numbers of Pharmaceutical Related Field (e.g., C07D, A61K, A61P, C07C, C07F, C07K) are used as the search entry for searching invalidation decisions from 2010 to 2019 (nearly ten years), and the invalidation decisions obtained from the search are further screened for invalidation decisions concerning granted claims with subject matters relating to compounds in the field of medicine. From the search, a total of 35 invalidation decisions are obtained. See Table 1 below for basic information about the relevant invalidation decisions.

 Table 1.  Basic Information about the 35 Invalidation Decisions

On this basis, the texts of the above 35 invalidation decisions (including the invalidation grounds involved, the exhibits submitted by both parties, claim amendments in the invalidation procedure, the evaluation opinions of the collegial panel, and the holdings of the invalidation decisions) are analyzed.

2. The Overall Statistical Analysis of the Invalidation Cases

1. Annual Distribution of the Invalidation Decisions

Figure 1  The Annual Distribution of the Invalidation Decisions

It can be seen from Figure 1 above that there were fewer patent invalidation cases involving compound subject matter from 2010 to 2016. Starting from 2017, the number of patent invalidation cases involving compound subject matter increased significantly, wherein 13 invalidation decisions were made in 2018.

2. Distribution of Invalidation Grounds

Figure 2  Distribution of Invalidation Grounds

From Figure 2 above, it can be seen that the main invalidation grounds involved in invalidation cases for patents with compound subject matter are the issue of inventiveness and the issue of insufficient disclosure of the description. In a total of 35 invalidation decisions subject to the statistical analysis, there are up to 24 cases involving inventiveness invalidation ground, which accounts for nearly 70%. It indicates that the inventiveness issue is a hot issue in current invalidation cases for patents with compound subject matter. In addition, there are 17 cases involving insufficient disclosure of the description, which accounts for nearly 50%. In addition to the issues of inventiveness and insufficient disclosure of the description, there are also 6 to 10 invalidation cases involving lack-of-support issue, novelty issue and beyond-original-scope issue. Finally, there are also a small number of invalidation cases involving lack-of-clarity issue and other articles/rules related to invalidation (such as practical applicability, Article 5, Article 25).

3. Distribution of Invalidation Holdings

Note: The above “invalidation percentage” statistics includes both full invalidation and partial invalidation.

Figure 3  Distribution of Invalidation Holdings

Figure 3 above analyzes the distribution of invalidation holdings of various invalidation cases (only for claims with compound subject matter). First, of all the 35 invalidation decisions, 22 decisions maintained the validity of the patents, one decision declared the patent invalid in part, and the other 12 decisions declared the patents invalid in their entirety. The full invalidation percentage is 34.29%, and the partial invalidation percentage is 2.86%.

Since it is found in the statistical analysis that some patents involve multiple invalidation decisions, in order to more accurately reflect the invalidation percentage of the corresponding patents in the invalidation procedure, we conduct statistic analysis on a case-by-case basis (i.e., a case involving multiple invalidation decisions is still counted as one case.). It is found that the above 35 invalidation decisions involve a total of 28 patents, of which 16 patents were maintained valid, one patent was declared invalid in part, and the other 11 patents were declared invalid in their entirety. The full invalidation percentage is 39.29%, and the partial invalidation percentage is 3.57%. The invalidation percentages calculated in this dimension are higher than the invalidation percentages calculated based on the number of the decisions, and can also better reflect the probability of a compound patent being declared invalid in the invalidation procedure. It can be known from the above invalidation percentages that in the invalidation procedure, nearly 40% of the cases involving patents with compound subject matter declared the patents invalid in their entirety, and 3.57% of the cases declared the patents invalid in part.

In addition, given that the compound subject matter is mainly Markush general structure and specific compounds, we further divide the cases based on the claimed subject matters for analysis of invalidation holdings thereof. For cases involving protection of only a single compound (i.e., protection of only one specific compound), out of all 19 invalidation decisions, 12 decisions maintained the validity of the patents, and the other 7 decisions declared the patents invalid, with an invalidation percentage of 36.84%. In contrast, for cases involving protection of Markush general formula or multiple specific compounds, out of all 16 invalidation decisions, 10 decisions maintained the validity of the patents, one decision declared the patent invalid in part, and the other five decisions declared the patents invalid in their entirety, with a full invalidation percentage of 31.25% and a partial invalidation percentage of 6.25%. Given that claims of compound subject matter generally constitute the core patents of each patentee, when the core patents only cover a single specific compound, more than one-third of the patents are still invalidated in the invalidation procedure.

Finally, in terms of the technical effects targeted in the invalidation procedure, a statistical analysis of cases without quantitative experimental data in the original application documents finds that in all five cases without data, they all resulted in invalidation in their entirety, with an invalidation percentage of 100%. The role of unexpected technical effects in the inventiveness determination in the invalidation procedure and the acceptance of supplementary experimental data showing the effects will be described in detail in the following parts.

4. Distribution of Invalidation Holdings for Each Invalidation Ground

Figure 4  Distribution of Invalidation Holdings for Each Invalidation Ground

It can be seen from Figure 4 above that although the invalidation grounds involved in the invalidation decisions are widely distributed, the main grounds are still issues of inventiveness, insufficient disclosure and novelty. In addition, further analysis of the proportions of cases maintaining validity and resulting in invalidation declaration under each invalidation ground reveals that the main invalidation ground is the lack of inventiveness of the corresponding compound. In fact, out of a total of 15 invalidation decisions declaring the patent invalid, 10 were due to the lack of inventiveness of the corresponding claims, three were due to the lack of novelty of the corresponding claims, and two were due to insufficient disclosure of the description. Grounds such as lack of support, beyond-original-scope, and lack of clarity have not caused a single patent within the range of the statistical analysis to be declared invalid.

However, it should be noted that the above statistical analysis takes into account the circumstances in which the patentees amend the claims in the invalidation procedure. Regarding the issues such as lack of support and lack of novelty raised by the petitioners, if the patentees correspondingly limit the claims’ protection scope, the final invalidation decision may not reflect invalidation of the amended claims based on the existence of the corresponding defects. Thus, the above-mentioned invalidation grounds still have significant effect in limiting the actual protection scope of the patents involved in the above cases.

3.  Related judgments of Chinese courts

Statistics

In relevant databases, the International Classification Numbers of Pharmaceutical Related Field (e.g., C07D, A61K, A61P, C07C, C07F, C07K) are used as the search entry for searching patent invalidation administrative litigation from 2010 to 2019, and the results obtained from the search are further screened for judgements concerning granted claims with subject matters relating to compounds in the field of medicine. From the search, the following relevant judgements are obtained.

 Table 2

Among the above seven groups of administrative cases, the Vildagliptin case did not actually proceed into substantive administrative litigation because the plaintiff withdrew the claims on its own initiative.

The following table is obtained upon summarizing the holdings of the remaining six groups of cases:

Table 3

Based on the content of the table above, the following can be seen:

(i) Five of these six groups of litigation cases were appealed to the court of second instance, and two of them were even arraigned by the Supreme People’s Court. In fact, it is understood that in the Ticagrelor case and the Tenofovir Dipivoxil case, the Patent Reexamination Board filed retrial requests to the Supreme People’s Court after receiving the second-instance judgments, but has not yet received a ruling from the Supreme People’s Court on whether or not to arraign the cases.Based on the content of the table above, the following can be seen:

(ii) The holdings of the court of first instance and the Patent Reexamination Board were highly consistent, and none of the holdings of the Patent Reexamination Board were revoked; in the five appeals, the court of second instance revoked the holdings of four of them. The revocation percentage is as high as 80%.

(iii) For the two cases that entered the retrial procedure, the Supreme People’s Court revoked the judgments of the second instance and upheld the decision of the Patent Reexamination Board. The percentage of revocation by the Supreme People’s Court is as high as 100%.

The above-mentioned six groups of administrative cases are all mainly focused on inventiveness issue, and all involve the issue of whether or not the supplementary experimental data can be accepted.

[1] The authors are all patent agents at King & Wood Mallesons (Beijing).

Contact Person: TAI Hong, tinatai@cn.kwm.com, 010- 58785132