On ＂Patent Invalidation＂ of Drug Patents

As an important protection in the process of drug development, patent is self-evident. The number of patents owned by an enterprise not only forms important intellectual property protection for products, but also reflects the status and value of the enterprise. However, patents are also divided into "three, six and nine grades". A high-quality authorized patent not only protects the value of the product, but also has high value itself. However, a patent full of loopholes is difficult to obtain authorization. Even if it is authorized, it will be easily challenged by competitors, and eventually it will be "invalid", which will bring serious economic losses to enterprises. Therefore, it is extremely important for the pharmaceutical industry to understand "invalid patent" and achieve "from defense to attack"

What is the "patent invalidation system"

Patent invalidation system, which is regarded as "a corrective procedure for wrong patent authorization", has attracted much attention in patent systems in various countries, and its essence has the functions of error correction, defense and defense. The invalidation of patent will have a direct impact on the validity of patent right, and whether the patent right is effective and stable is an important premise and index to measure the quality of patent. Generally speaking, the invalidation of an invention-creation experience is finally kept valid, and its patent value is higher, which will also have an important impact on the subsequent measures taken by the patentee and the invalid claimant.

With the rapid increase in the number of drug patent applications and patent authorizations in China, there are more and more phenomena of using invalidation to challenge other people’s drug patents and expand their own benefits. Even the patent departments of some companies will organize personnel to "attack" competitors’ patents; At the same time, in order to keep the core claims of their own patents, some patentees have reduced their patent protection scope through invalidation to avoid subsequent patent litigation. In short, it is one of the necessary skills for every pharmaceutical company to protect its "core rights" by using the patent invalidation system as much as possible.

Based on the case of sildenafil patent in Pfizer, the author explains the importance of "invalid patent". In this case, the key points of the game for "invalid reasons" are as follows:

1. The patent specification shall explain the drug activity, preparation method, effective dosage and use method of the drug, and describe the medical effect of the drug on the second indication in detail through animal experiment or clinical trial data. However, the writing of the instructions is far from the above requirements, so that technicians in the technical field can’t know what medicine to use, what disease to treat, how to use the medicine correctly and how effective it is by reading the instructions without creative labor.

Second, this patent specification only generally records that the compounds of the present invention have been tested in vitro and found to be strong selective inhibitors of PDE-V with specificity for cGMP; Ordinary technicians in this profession can’t see what the so-called particularly preferred compounds are from this description, while the claims seek to protect the use of four products, and ordinary technicians in this profession can’t determine the relationship between these four products and the particularly preferred compounds in the above text description.

Three, the applicant made a major amendment to the claim, in fact, after the original claim was deleted and reassembled. This modification cannot be directly and undoubtedly derived from the information disclosed in the original specification and claims. Obviously, because the original specification and the claims did not fully disclose that the products in the present claims have clear medical functions and unexpected technical effects as required by the Patent Law, the modification results of the claims cannot be directly and undoubtedly derived from the specification and the original claims.

4. As the existing cGMP and PDE inhibitors can be used to treat ED, it has been suggested and suggested many times in the relevant literature, it is not difficult for ordinary technicians in this field to draw the results in the claims from these tips and suggestions.

On the above questions, Pfizer answered each "invalid reason" one by one, proving that there is no problem with the creativity of its patent. After that, the original Patent Reexamination Board of China National Intellectual Property Administration finally declared the patent authorized by the original research company Pfizer invalid through in-depth research. Pfizer was dissatisfied with the above decision of the original re-examination board, and immediately appealed to the Beijing No.1 Intermediate People’s Court to sue the original patent re-examination board, requesting the court to cancel its decision of invalidation. After repeated debates, in 2006, the Beijing No.1 Intermediate People’s Court officially announced the revocation of the decision of No.6228 made by the original Patent Reexamination Board. Since then, Pfizer’s Viagra has made huge profits in China every year, but sildenafil produced by domestic generic drug companies cannot be listed. This situation continued until the listing of domestic sildenafil "Jinge" in 2014.

The importance of "public opinion"

The application for "invalid patent" can not be disputed only after authorization. When the application documents appear, they can be questioned in the form of "public opinions". Article 48 of the Detailed Rules for the Implementation of the Patent Law stipulates that "from the date of publication of an application for a patent for invention to the date of announcement of the grant of a patent right, anyone may put forward opinions to the patent administration department of the State Council and explain the reasons", which is also called "public opinions" in the industry. Pharmaceutical enterprises should make full use of this provision to protect their own interests to the maximum extent.

The rosiglitazone case illustrates the importance of "public opinion". In 1993, GlaxoSmithKline applied for a series of patents including pharmaceutical compounds and compositions, such as the invention patent application with the application number of CN98805686.0, which requested to protect the pharmaceutical composition containing 2mg~8mg of rosiglitazone. The application date was June 2, 1998, the publication date was July 5, 2000, and it was authorized on July 2, 2003. It can be seen that it took about three years from the disclosure of the patent application to the announcement of authorization. During these three years, the relevant enterprises in China did not put forward any "public opinions".

In 2004, when Shanghai Sanwei Pharmaceutical, Zhejiang Wanma Pharmaceutical, Chongqing Taiji Group and other domestic enterprises have invested a lot in research and development of this drug or entered the stage of drug registration, they suddenly received a lawyer’s letter from GlaxoSmithKline, claiming that the products developed by the above-mentioned enterprises infringed their patent ZL98805686.0, demanding that the above-mentioned enterprises stop the research and development and listing of related products and compensate for the losses. As a result, these enterprises jointly requested the original patent reexamination board to declare the patent invalid. Although the case ended in GlaxoSmithKline’s abandonment of the patent, it lasted for a long time and had a great impact, causing huge losses to China enterprises.

Analyzing the case, when domestic pharmaceutical companies were ready for production and even obtained the approval of drug production, they found that they were facing the infringement lawsuit of foreign pharmaceutical companies, so they passively responded and rushed to the original Patent Reexamination Board to file a patent invalidation request in an attempt to invalidate the patent. In this case, even if the patent right can finally be declared null and void in whole or in part, China enterprises still face huge market risks and interest losses due to the long trial period and long-term uncertainty of rights.

In fact, an application for a patent for invention will be published within 18 months from the date of filing (unless the applicant requests it to be published in advance), and then the Patent Office will start substantive examination on it at the request of the applicant. If the examiner thinks that the patent application conforms to the relevant provisions of the Patent Law and the Detailed Rules for the Implementation of the Patent Law, the patent right will be granted and announced to the public, otherwise, it will be rejected. After the patent is granted, anyone (the third party) who thinks there is a problem with the patent grant may go to the relevant department to request that the patent be declared invalid. Of course, if you are not satisfied with the invalidation or review decision made by the relevant department, either party can also bring a lawsuit in court. Generally speaking, after an invention patent is published 18 months from the date of filing, it sometimes takes 2-4 years to decide whether to authorize it. At this stage, whether the patent application can be finally authorized is still in a pending state, which is the time allowed to put forward "public opinions" as stipulated in Article 48 of the Detailed Rules for the Implementation of the Patent Law. It can be seen that how to reduce the losses caused by patent disputes relatively, the "public opinion" before patent authorization is very important.

In recent years, Chinese pharmaceutical enterprises have paid more and more attention to the protection of intellectual property rights. The intellectual property departments of many large pharmaceutical companies have even reached the scale of 100 people. In addition, for some important patent applications, some pharmaceutical companies will take them to more professional patent agencies for secondary processing and polishing before submitting applications. It can be seen that pharmaceutical companies pay more and more attention to patent application and are more and more cautious about controlling patent quality. With the increasing number of patent challenges and invalid patent applications, the trend of domestic pharmaceutical companies turning from defending to attacking intellectual property rights has been initially established.

(Qiang Sen)