Obtaining a "Secondary" Patent for a Drug as a Tool for Ousting an Original Drug from the Market

Problems of the simultaneous existence of primary and secondary patents for medicines

As a rule, Russian pharmaceutical companies wait until the patent for the original drug expires in the Russian Federation and only then enter the market with a generic, starting preparations for registration of a generic drug in 1-2 years, which has a qualitative and quantitative composition of active ingredients equivalent to the reference drug, an equivalent dosage form, and similar therapeutic activity.

But recently, there has been an increasing trend when the originator's patent, including the secondary one, has not yet expired, and the Russian pharmaceutical manufacturer has already protected exclusive rights by obtaining its own secondary patent for a similar drug, drawing up the claims of the invention in such a way that it contains distinctive features in the form of, for example, another dosage form or composition with excipients. At the same time, the claims do not disclose each feature or equivalent feature of the invention patented by the originator, which allows him to enter the market with an analogue without violating the exclusive rights of the originator.

What is the difference between primary and secondary patents?

To better understand how this is possible, let's look at the differences between primary and secondary patents.

Patents for the active ingredients of a drug are called primary patents. They defend inventions concerning a newly created molecule with therapeutic activity. In this case, this activity can only be preliminarily established.

Secondary patents are patenting whose claims indicate, for example, the specific crystalline or enantiomeric form of the substance, the method of preparation, use, dosage of the active substance, preferred pharmaceutical forms, the composition of excipients, the purity properties of the substance, etc., in relation to already known compounds as distinctive features of independent claims.

The possibility of broad legal protection afforded to genuinely new pharmaceutical substances under previously obtained patents of originators (e.g., the Markush formula, including derivatives with different properties, mention of the potential use of the new molecule for the treatment of a wide range of diseases, etc.) is directly related to the fact that there was no strict requirement for detailed disclosure and confirmation of the efficacy of the treatment and the possibility of implementing the claimed destination. At the same time, the description of the properties of the new molecule and the method of its synthesis for protection could be presented in a simplified (schematic) way. Convincing examples were not required to convince the patent office of the feasibility of the invention.

There are always more secondary patents than primary ones. It is not possible to cover the entire range of possible options only for the originator, which allows, after conducting a preliminary patent search, to develop a competent strategy for circumventing the existing patent of the originator, which prevents entering the market with a similar drug.

Features of obtaining secondary patents today, taking into account the stricter requirements for the assessment of inventive step

According to the Order of the Ministry of Economic Development of the Russian Federation dated 31.03.2021 No 155 "On Amendments to the Rules of Inventions", approved by the Order of the Ministry of Economic Development of the Russian Federation dated May 25, 2016 No 31, an invention cannot meet the "inventive step" condition if it is based on the creation of a chemical compound that is:

• the form of a known chemical compound;
• a derivative of a known chemical compound;
• a compound that does not exhibit properties that are new in comparison with the known compound in qualitative or quantitative terms, which do not clearly follow from the state of the art for the skilled person.

Confirmation of the possibility of carrying out the invention includes the following information:

• indicating the influence of this form or derivative on the etiopathogenesis of the disease or on the state of the body;
• about the connection of the diagnostic factor with them;
• reliable data confirming the suitability of a certain form or derivative of a known chemical compound, obtained, in particular, in an experiment on adequate models.

Thus, it is now possible to obtain a secondary patent only if the manifestation of new properties and the unexpectedness of the technical result are proven. However, an obstacle to obtaining free access to the market with a secondary patent is also Article 1358.1 of the Civil Code of the Russian Federation, which provides for the legal regulation of dependent inventions.

The essence of dependent patent subject matter is that it cannot be used without the permission of the patent holder for the patent subject matter to which it is dependent. Thus, the exclusive right of the patent holder to the dependent subject matter is limited: it does not include the exclusive right to use the dependent subject matter.

Therefore, the strategy for patenting secondary patents is primarily to ensure that the secondary patent is not dependent!

Overview of Existing Strategies for Obtaining Secondary Patents

Let's consider the patenting strategy using the example of a chain of secondary patents for a polymorphic form of a known substance.

Patents for inventions NoNo 2706166, 2770301, 2770300, 2536254, 2733719, and Eurasian patents NoNo 044497, 041334, 046006 were obtained by a well-known Russian pharmaceutical company for a new polymorphic form of trimebutine maleate, a method for obtaining and its application, a finished dosage form, and a composition.

Most applications have been filed by segregation in order to maintain a single priority date, without the possibility of opposition on the basis of lack of novelty and/or inventive step of earlier applications of the same authors. In fact, all patents contain the same description, and the same technical results in terms of the properties of a given compound when used preparatively, in particular a higher dissolution rate, increased storage stability, and low hygroscopicity. On the same date, applications were filed in the Russian Federation and Eurasia, as a result, the patent holder has formed an impressive portfolio of patents for essentially the same medicine, and in the event of the cancellation of one patent, another will be valid. This is the case when it is not the quality that is important for the applicant, but the number of patents, with which he maximally expands the scope of his claims, but not within the framework of one patent, but in the aggregate of several, which significantly complicates the procedure for their revocation.

At the same time, it is possible to annul such patents, taking into account the newly tightened rules and the formed new approaches to assessing the inventive step.

For example, it follows from the Resolution of the Presidium of the Intellectual Property Court dated 19.01.2024 in the case No SIP-877/2022 in relation to the new crystalline form of a known substance that "verification of the new crystalline form for compliance with the criterion of protectability "inventive step" includes the analysis of:

• the well-known (or obvious to the specialist) of the polymorphism of a particular substance (and not the polymorphism as a phenomenon as a whole);
• the knowledge (or obviousness for the specialist), including standardization, of the methods for obtaining a specific crystalline form of a particular substance;
• surprise for the specialist of a specific change in physical and chemical properties, effect (surprise of the technical result) in comparison with the known forms of a particular substance.

The Presidium of the Intellectual Property Court noted that neither the production of a new crystal form of a substance known for its polymorphism by standard methods, nor the study of its properties and the demonstration of differences in its properties from other known crystal forms or from an amorphous form is an invention that meets the patentability criterion of "inventive step", if the properties described in the relevant application do not reveal an unexpected effect for a skilled person (technical result), which makes it possible to use a new crystalline form in a way that the known crystalline forms of the same substance could not be used."

Methods of promoting a patented analogue of an original drug

Next, let's consider how obtaining a "secondary" patent for a drug can oust the original drug from the market.

The effects of the original and secondary drugs are the same and their properties are similar to those of the original drugs. They contain the same active substance as the original, but in a different form, and may differ from it in excipients, type of medicine, production technology, etc.

How can the owner of a secondary patent provide an advantage for his drug over the original one?

• Expansion of the number of dosage forms of the drug (the original is produced only in tablets; the new drug is additionally in capsules; suspensions);
• Setting a recommended price for the distributor of 50 percent or less of the cost of the original drug;
• Development of more convenient packaging for the end consumer, taking into account the duration of the treatment course;
• Maintaining a flexible pricing policy, especially in tenders in the hospital market due to low costs;
• Expansion of consumer activity by attracting doctors, pharmacists, pharmacy employees, distributors as a target audience;
• Active advertising;
• Emphasis on import substitution in tenders, obtaining subsidies for the development of priority areas.

In conclusion, I would like to note that not only from the point of view of the development of the pharmaceutical field and healthcare, but also from the point of view of modern society, it is important to maintain a balance. Both original drugs and medicines produced under secondary patents perform an important social function, as they are more accessible to the public compared to expensive originals. Subsequent developments in relation to known drugs often make it possible to obtain not only less expensive drugs, but sometimes even more effective ones. But the interests of the originators, who spent the greatest effort and money on the initial development, should not be forgotten, their rights must be respected and act in accordance with the letter of the law.