Can old drugs apply for patent protection for new use?

Old drugs The new "old drugs" are not limited to existing drugs already on the market, but should also include Zeng/Potential candidates now in preclinical or clinical research, although not a new concept, but the new use of old drugs can reduce the failure rate and development costs, given the high failure rate of new drug clinical research in recent years, the search for new indications for existing drugs has become very attractive and optimize the cost of pharmaceutical companies/More importantly, the new use of old drugs is very suitable for the treatment of rare diseases. Due to the small number of patients with rare diseases and limited market space, it is difficult to make profits within the framework of traditional drug development. Most enterprises are not willing to enter these fields, and the new use strategy of old drugs can make up for the lack of new drug development in this field.

However, the challenges faced by the new use of old drugs mainly come from three aspects:

1. patent issues

The new use of old drugs first faces the threshold of intellectual property rights. The patent application and implementation of new indications are the key reasons that motivate pharmaceutical companies to develop new use of old drugs, because it has a great impact on product revenue. If the new use of a known drug is creative, then the drug will be protected in most markets around the world, but in most cases the new indications have been reported in the literature or studies have found that unless the patent owner can prove that the indications he developed are not within the scope of the existing patents, otherwise it is difficult for the new use of this old drug to obtain patent protection. Therefore, it is particularly important to determine the target indications and the strength of patent protection as soon as possible.

2. Policy Regulators

American NDAClass I, Class VI (New Indications) and Supplemental New Drug Applications (sNDA, new indications) are applicable to the application of new use of old drugs, three categories (new dosage forms) and four categories (new combination) are applicable to the new use of old drugs or new dosage forms, most of the new use of old drugs are approved before the expiration of the original research drug patent. In addition, the FDA grants a three-year exclusivity period to older drugs that treat new indications.

3. Organizational Barriers in the Industry

If a project is not part of the company's core research and development direction, it is likely that the project will be suspended due to funding and other issues, which is very detrimental to the redevelopment of drugs for new indications, which can be financed with the help of CRO.The company platform and policies support the completion of projects that cannot be completed within the company. In addition, the current sharing of drug mechanism information and clinical pharmacovigilance information between enterprises is still very conservative, and it would be very helpful to further share the results of the new use of old drugs in progress.

Is the new use of the drug a patentable object?

Is a drug with a new use patentable? The answer is yes, this situation can apply for a new indication (new use) patent, of course, whether it can be approved has to examine the three properties, of which the novelty is mainly concerned about whether this new use has been substantially disclosed, China's patent "review guide" pointed out that "for the pharmaceutical use of the invention involving chemical products, the novelty review should consider the following aspects:

（1) Whether the new use is substantially different from the original known use. Inventions that are only expressed in different forms but essentially belong to the same purpose are not novel.

（2) Whether the new use is directly revealed by the mechanism and pharmacological effects of the original known use. Uses that are directly equivalent to the original mechanism of action or pharmacological effects are not novel.

(31) Whether the new use belongs to the upper concept of the original known use. It is known that lower-level uses can destroy the novelty of upper-level uses.

（4) Whether the characteristics related to the use, such as the object of administration, the mode of administration, the route, the dosage and the time interval, have a limiting effect on the pharmaceutical process. The distinguishing features embodied in the course of medication alone do not make the use novel."

Creativity mainly examines whether this use is supported by sufficient scientific evidence (e. g. preclinical and clinical data), while practicality is to avoid the pit of "diagnosis and treatment of disease.

For the patent protection of this type of drug, the original research company has two ways to respond, namely:(1) to apply for an extension of the protection period of the existing compound patent of this kind of drug, or (2) for a new patent for this class of drugs. In practice, many pharmaceutical companies tend to adopt the second strategy, that is, to apply for new patents for such drugs. This new patent strategy maximizes the life cycle of drug patents and expands the scope of patent protection for companies, but it also encounters many limitations of patent law and examination practice.

In the United States, although the compound itself may not be patent protected, the compound is used for a new indication, that is, a new use (or a second indication) of a known pharmaceutical product. If it is indeed new and unexpected, it is usually possible to be patent protected, A defining characteristic of factors such as gender, race, or age that influence the effectiveness of treatment. Patent offices in many other countries consider that a second-indication patent unduly extends the protection of a drug product without the creation of a new drug product, and therefore refuse to grant a patent for such claims.

Conclusion

In specific cases, new uses of medicinal compounds/New indications are objects that can be protected by patents, but obtaining patent authorization needs to cross the challenges of novelty and creativity, which requires pharmaceutical companies to pay attention to the requirements of patent law and examination practice during the research and development process. Under the trend of internationalization of production and market, the international application of pharmaceutical patents has become an indispensable strategic need. It is an essential content of high-level patent legal service to formulate different patent application strategies by using different provisions of claims for new uses of compounds in different countries. The new use of a known drug protected by a patent can have a huge profit return. Therefore, once a pharmaceutical company discovers a new indication for a known drug, even if it does not own the patent right for the compound, it should file an international application for a patent for the new use of the substance as soon as possible, and determine the form and scope of the claims for the national phase of the application for entry into the country for the different provisions of each country.