In this study, the total number of patent families reviewed was 12,350, out of which 3179 were granted patent families. A distinction between research activities for each NTD has been observed. Among the NTDs, leishmaniasis, dengue, and rabies received the highest number of families, while taeniasis and dracunciliasis the least. The number of granted patent families and total patent families for each NTD is presented in Table 1. The overall patenting trend for NTDs is often characterized by the total number of simple families and granted patent families (by year when it was granted). As presented in Fig. 1, there is a substantial increase in patenting activities between 1985 and 2014 both in the total numbers of patent families including applications and in granted patent families. Although, total patenting activity was fluctuating between 2003 and 2008 which was followed by 6 years stagnation, mainly because of the decreasing number of applications. The increase in the granted families is continuous but slow.
The variable trends in NTDs patenting can be classified into three distinguished catergories. The first category shows an increasing trend in the number granted patents based on patent families (buruli ulcer, Chagas disease, dengue, onchocerciasis); the second category is mostly characterized by stagnation (echinococcosis, leishmaniosis, leprosy, rabies, schistosomiasis, trachoma, yaws); while the third category lacks a clear trend due to the low number of filings (dracunculiasis, food-borne trematodiasis, human African trypanosomiasis, lymphatic filariasis, soil-transmitted helminthes, taeniasis). There was no significant increase in the number of granted patent families for any of the NTDs in the last 10 years. The figures of annual patenting trends for each NTD are presented in Additional file 2.
While the biphasic trends of IDM and PCT diseases appear to be similar, the patenting trends of these two groups reveal a slight noticable difference. In comparison with the PCT group, the IDM group show a more intense growth period and stagnation after 2008 (see Additional file 2).
Patent applications are not published until after 18 months, so information after 2014 is not presented in Fig. 1. Patents expire after 20 years. Legal status is important for information on commercial exploitability of patents. Analysis of current legal status of the patent families of NTDs, presented in Fig. 2, reveals that almost 50% of the patents are non-active. This fact suggests that investing in NTDs has a low commercial value. Among the 17 NTDs identified, the prevalence of non-active patents is noticeably high in leprosy, schistosomiasis, trachoma and trematodiasis (see Additional file 2).
Analyzing the top priority countries (countries where initial patent filing was submitted) for the granted patent families, it was observed that the main priority countries are the United States (US), European Union (EP), Korea (KR), Japan (JP) and Great Britian (GB) in the last 30 years. However, by focusing on the trend of total number of patent families, the leading countries are the US, China (CN), JP, EP, and GB. The gap between the first two priority countries is high, the US and China are with 6154 and 2423 patent families respectively. However, different patenting activity level of US and China can be detected by ratio of applications for patent families to granted patent families: 1898/3302 and 87/1525 respectively. With respect to NTDs, China appears as an emerging priority country compared with the US since 2010 as presented in Fig. 3. This trend is observed particularly for echinococcosis, rabies, schistosomiasis, and soil-transmitted helminthes. For example, China has a set priority for the soil-transmitted helminthiasis since 2010. Nonetheless, US has kept its leading role in intensive research on NTDs, such as leprosy, leishmaniasis and dengue. An interesting exception is observed for trematodiasis, which has Russia as its priority country.
In the US, firms hold a large percentage of patent families in comparison to other interest groups such as individuals, universities, governments, and institutes. In China, France, Korea, and Russia, more than 50% of patents and applications were assigned to entities other than firms. By focusing on the assignee types of granted patent families, the role of firms is dominant, except for France, Korea and Russia. In Korea, the universities, and in Russia, no specified assignees are the major patent holders. Distribution of assignee types among priority countries is assessed in Fig. 4.
Figure 5 provides an overview of the identified NTDs patent landscape in the form of technological fields. The main technological subdomains are pharmaceuticals, biotechnology, organic fine chemistry, analysis of biological materials, basic materials chemistry and medical technology. According to the NTDs trends, pharmaceuticals and biotechnology accounted for most patent families filed in the last 30 years. These two fields have shown substantial growth since 1985. Filings in organic fine chemistry have dropped in the last 10 years. The analysis of biological materials seems to be a popular field of innovation. Patent families for basic materials chemistry and medical technology have also shown substantial growth, in the overall analysis, but they account for a small portion of the filings. Focusing on the granted patent families, the stagnation/decline of the pharmaceuticals, biotechnology, organic fine chemistry fields are not yet present. The percentage of technical subdomains (pharmaceuticals, biotechnology, organic fine chemistry, analysis of biological materials, basic materials chemistry and medical technology) for alive versus non-alive patent families were similar. The highest proportions were observed in the pharmaceutical field, and the high proportion of dead patent families in the pharmaceutical is as a result of a decline in patent applications. Additionally, by comparing the technical subdomains of the IDM and PCT groups examined, it was observed that they have the same subdomains ranking order. However, while the hierarchy among subdomains of IDM is rather constant, there are changes in the positions of the subdomains of PCT. A very important observation is the clear decline in the number of patent families for pharmaceuticals and organic fine chemistry in the group of PCT.
The IPC classification of NTDs patents showed that class A61 is the most prominent class in which NTDs research patents are being categorised. In respect of this categorisation, A61K39/00 (medicinal preparations containing antigens or antibodies) is the most dominant IPC subgroup within the A61 class. Detailed research focus of each disease is presented by IPC subgroups in Additional file 2.
For a patent landscape analysis, analyzing the distribution of active patent applicants in a research field is important. With respect to NTDs research, a lack of dominant assignees (more than 33% of patents) was observed (Fig. 6). The main original assignees for NTDs research are governmental institutions and universities, such as Univeristy of California (US) or Pasteur Institute (FR). Among current assignees, firms such as Merck, Vertex Pharma Inc. tend to take more financial risks on NTDs research.