Montaury Pimenta, Machado & Vieira de Mello
One of the most common questions regarding patent protection in Brazil refers to whether there is a possibility of protecting second medical use of known chemical compounds. The answer is simple: yes, it is possible to protect second medical use in Brazil. However, considering some particularities of the Brazilian Industrial Property Law and its interpretation by the Brazilian Patent and Trademark Office (BPTO), it is extremely important to give proper attention to the correct way of drafting not only the set of claims, but the whole patent application, in order to guarantee the most effective protection.
The only acceptable way of drafting second medical use claims in Brazil is the Swiss-type format; namely, the use of compound X characterised by being in the manufacture of a medicament for treating disease Y. However, this rule became confusing for foreign applicants since the publication of new Guidelines for the Examination of Patent Applications in the Chemistry Area. Based on these guidelines, since 2018 the BPTO has been accepting certain claim language to define a medical application of a compound or composition in two specific situations. The first is when a new compound or composition has already been claimed by its qualitative and quantitative features in an independent claim and there is a dependent claim seeking protection for a medical application of this compound or composition. The second possibility is to have an independent claim seeking protection for a new compound or composition by claiming its qualitative and quantitative features along with its medical use. In this case, the medical application is considered as a secondary feature, the main features being those related to the compound or composition itself. For example, a dependent claim reciting a “composition as defined in claim 1 characterised by being for the treatment of disease Y” provided that the composition is well defined in claim 1 by its constituents and amounts therein, is patentable in Brazil if the patentability requirements of novelty, inventive step and industrial application are fulfilled. Similarly, an independent claim reciting a “composition characterised by comprising X to Y% of component A; X to Y% of component B; and X to Y% of component C, for treating disease Z” will also be accepted if the previously mentioned patentability requirements are met, since the disease treated by the composition is an additional and therefore secondary feature.
Accordingly, when it comes to a new medical use of a previously known compound or composition, an independent claim defining the product by its constituents would not be novel and inventive and could not be patented. The only new feature would be the second medical application that cannot be protected in any other way than through a Swiss-type claim.
The situation can get even more complicated when the foreign applicant is familiar with European patent prosecution. Although the Brazilian Industrial Property Law is similar to the European Patent Convention (EPC) in several aspects, the interpretation that the BPTO gives to the said law is much stricter when compared to the applicability of the EPC made by the EPO. A classic example is that the EPO allows independent claims drafted as ‘product X for use in the treatment of disease Y’ to seek protection for second medical use regardless of whether the product is qualitatively and quantitatively defined by its constituents. This practice usually makes foreign applicants believe that the same language is accepted in Brazil, which is not the case. While the Brazilian Industrial Property Law is very clear when stating that methods of treatment are not patentable, the prohibition of certain claim language is not evident on reading the law, as exemplified above. Most of the time, it is necessary to be a Brazilian patent specialist or to have extensive experience with Brazilian practice to have these specific concepts well established.
In view of this, drafting an effective and permissible set of claims is a key aspect for patent applications related to second medical use in Brazil. In addition, there is another relevant issue that must be taken into consideration not only for second medical use applications, but for all patent applications filed in Brazil. According to the BPTO’s interpretation of Article 32 of the Brazilian Industrial Property Law, after the examination request, only amendments intended to limit the claimed scope are allowed. Among other things, this means that it is not possible to add or change the claimed categories after the request for examination. Therefore, if a new medical use of a known compound is claimed as a ‘compound for use’, it will not be possible to redraft this claim in the Swiss-type format after the examination request, and the application will most likely be rejected by the BPTO. This limitation imposed by the BPTO makes the examination request a decisive moment for Brazilian patent applications, so it is imperative to carefully analyse the pending set of claims at this point and, if necessary, amend it before the examination request in the most effective way to safeguard the scope of protection during the substantive examination.
Moreover, it seems that the outcome is not very encouraging from a legal perspective. A few court actions have been filed against the BPTO in an attempt to overrule the decision of rejecting applications related to second medical use based on the strict understanding that non-Swiss-type claims cannot be amended into Swiss-type claims after the request for examination. Regrettably, the Brazilian federal courts tend to follow the BPTO’s position in these cases, thereby maintaining the rejection decision of patent applications that, for example, initially claimed a method of treatment and only after the examination request the applicant decided to redraft the set of claims in the Swiss-type format. This fact corroborates the importance of having the set of claims properly drafted before the examination request.
As to the patentability requirements, the novelty of second medical use claims will be assessed based on the disease or condition to be treated. Features related to dosage regimen, route of administration, type of patient and the like do not render the second medical use novel. In other words, a second medical use is considered novel only if it relates to the use of a known substance to manufacture a medicament for treating or preventing a disease other than that for which said product was already used in the prior art.
However, the most challenging requirement to have a patent for a second medical use granted in Brazil is not novelty, but inventive step. To this end, the BPTO analyses five specific topics to check the inventiveness of a second medical use, namely:
- the mechanism of action;
- the aetiology of the disease;
- the structure-activity relationship;
- the side effects; and
- the symptoms of the disease to be treated.
These five items can be assessed with ‘yes’ or ‘no’ answers to the following questions:
- Mechanism of action – is the mechanism of action of the compound involved in the new use inferred from its mechanism of action for the medical use already disclosed in the prior art?
- Aetiology of the disease – does the new use relate to the treatment of a disease whose aetiology is the same aetiology of the disease related to the use already disclosed in the prior art?
- Structure-activity relationship – is the new use inferred from the structure-activity relationship of the drug in comparison with structurally related molecules, that is, from structural analogy with other compounds which present the same claimed activity already disclosed in the prior art?
- Side effects – is the new use inferred from the disclosure of adverse effects known from the prior art for the drug in question?
- Symptoms of the disease to be treated – is the new use inferred from the use of the compound for the treatment of a symptom of a disease already disclosed in the prior art, even if the claimed use refers to a different disease?
If the answer to all these five questions is no, the second medical use can be considered inventive.
Besides the novelty and inventive step requirements, a patent application must also bear clarity, sufficiency of disclosure and support in the specification. These aspects might be considered additional patentability requirements which are not related to the invention itself, but to the way that the application is drafted.
The best way to guarantee that a second medical use claim will be considered clearly and precisely drafted is by specifying the exact disease (or diseases) which are treated. Any other definition broader than that can be deemed as unclear and imprecise and, therefore, not accepted. Vague terms and expressions must be avoided. For instance, instead of claiming the use of a substance in the manufacture of a medicament to treat a neurologic disorder, the applicant should define the specific neurological disorder(s). There is no obstacle to claim more than one disease. Rather than claiming respiratory disorders, a clear and precise claim would recite asthma or bronchitis, for example. Another use of claim language regarded as unclear by the BPTO is the definition of the disease to be treated by its mechanism of action, such as ‘use of compound X in the manufacture of a medicament that inhibits serotonin re-uptake’. In this example, the disease or diseases to be treated by compound X are not mentioned in the claim, even if in a broader manner.
As for any patent application, the specification of an application related to second medical use must clearly and sufficiently describe the new use. In addition, the evidence of this new use must be disclosed in the specification by the time the application is filed. No further information can be included later. However, when it comes to second medical use claims, some additional criteria are used by the BPTO to analyse the sufficiency of disclosure and the support of claims in the specification.
Although experimental assays are usually present in pharmaceutical patent applications, special attention is given to them in second medical use applications. In these cases, the BPTO requires not only in vitro tests to evidence the new therapeutic use, but also in vivo tests, since in vitro tests are not always confirmed in vivo. In addition, the BPTO expects the applicant to prove that the in vivo tests performed in animals can be extrapolated to the target patients, either humans or animals. Looking at the positive side, if there is enough support in the specification as filed, the in vitro data can be submitted during the prosecution of the application as additional evidence to assist the substantive examination.
Further, if the protection is claimed for the new use of a group of compounds defined by a Markush formula, this new use must be demonstrated for each compound. Any compound with unproved medical effect will not be entitled to patent protection even if it is quite similar to a compound for which the new medical use was proved in the specification.
Although the drafting of second medical use claims in Brazil is certainly not an easy task, particularly for foreign applicants, it is possible to get an effective and enforceable patent if some precautionary measures are taken, especially before the request for substantive examination. The BPTO’s effort to change the mindset of Brazilian examiners in 2019 by implementing measures to eliminate the delay in the examination of patent applications is also notable. Hopefully this is the beginning of a new era where the BPTO will finally be harmonised with the patent practice of the most notorious foreign patent offices, resulting in a positive outcome for the Brazilian patent system, not only for second medical use claims but also for all claim categories.