By Sojuzpatent's Senior Associates Maria Kuptsova and Tatiana Badaeva.
Published in the Life Sciences Lawyer Magazine.
Biotechnology is one of the most rapidly growing fields of knowledge. As a result, practice of patenting biotech inventions is changing very intensively. Antibody inventions represent a significant part of all biotechnological inventions. The development of such inventions requires significant investments and justifiable patent protection is crucial for them.
This article focuses on antibody patent protection in the Russia in light of current practice.
There are two ways of getting patent protection for inventions on the territory of Russia. The first one is through filing a national Russian patent application with the Russian Patent Office (RUPTO). The second one is through filing a regional Eurasian patent application with the Eurasian patent office (EAPO) since once a Eurasian patent is granted it is valid in all Contracting States, which include Russia.
Russian and Eurasian patents are independent. An interesting consequence of that is possibility of getting a Eurasian and a Russian patent protection for the same invention simultaneously.
Both these patents provide protection under similar provisions in Russia.
The scopes of rights of Eurasian and Russian patents are defined by each of features of independent claims or equivalent features known from a prior art.
Both patent offices devote increasing efforts to counterbalance inventors’ demands on one side and protection of public interests on the other. With that, their approaches are not the same.
Although both patent offices apply common general patentability criteria such as such as novelty, non-obviousness, and industrial applicability, some additional conditions shall be met to obtain a patent successfully.
In particular, both patent offices require that claims shall be supported by materials of an application. At that, an analysis whether this criterion is met is different in the EAPO and the RUPTO. Presently the EAPO is more loyal, e.g. it does not require that a separate example should be provided for each alternative feature included into a claim.
Furthermore, both patent offices have their own special rules regulating how to state claims, and which features should characterize that or those subject matter of an invention, and examiners pay much attention to analysis of claims in light of these rules.
When an invention relates to an antibody, the following is considered:
Further, the RUPTO considers antibodies as proteins and has the following additional requirements:
“In claims that characterize …protein, peptide or polypeptide, isolated from natural source or obtained in another way, having a same or a targetedly altered biological function… should be included: a name of a product, its biological functions (a type of activity, biological property) that determines its intended use in cases when it does not follow obviously from the name, number of corresponding…amino-acid sequence (if it was established) of physicochemical and other features, that allow to differentiate this substance from others”.
In turn, the EAPO considers antibodies as inanimate biotech products, so, a claim shall satisfy the following rules:
“In claims that characterize a product of inanimate nature whose structure is fully or partly revealed, following is included: structural formula or peculiarities of structure of such products, in particular …amino acid sequence for peptides, polypeptides and proteins.
For products that relate to inanimate objects with unestablished structure, claims contain a set of physicochemical and other features that allow identifying these subjects and distinguishing them from other already known products. Such features can be for instance features of their production method.
In the both above cases function or a type of activity and origin shall be also specified”.
As result, Russian and Eurasian patents relating to the same invention may provide different scopes of protection.
Nowadays the RUPTO aims to decrease the timeframe of application consideration as much as possible. So, a biotech patent might be granted in two years from the date of filing a national stage application. Another advantage of the RUPTO compared to the EAPO is that patent fees in the RUPTO are quite low. Thus, if a very quick patent is desired the filing a national Russian patent application may be a good way out.
While the prosecution process takes more time in the EAPO, filing a regional Eurasian application is advantageous from the viewpoint that it allows more opportunities for amending materials of an application, and providing arguments supporting the scope of claims and patentability of an invention.
Main approaches for characterization of antibodies in claims of Russian and Eurasian patents
The requirements of Russian and Eurasian patent legislations discussed above outlines specific and actually limited number of ways to characterize antibodies in claims. For example, it is impossible to characterize an antibody in a claim only by its functional features such as its capability to bind a certain antigen or capability to compete for binding with another antibody.
Roughly, there are two possible ways: characterizing an antibody with its structural features and characterizing an antibody with “other” distinguishing features along with its physical-chemical properties.
Further, we would like to discuss several common situations in connection with an antibody claim in the RUPTO and in the EAPO.
Characterizing antibody by its antigen binding region
Many antibodies are characterized in claims with features of its antigen-binding site. However, such features can be stated in claims very differently.
Sometimes an antibody or an antibody based artificial construct are characterized as “binding to an antigen X and comprising at least one domain responsible for the binding to the antigen” without an indication of domain sequences. In practice of the RUPTO in such cases, it is always requested to indicate concrete “essential” sequences of antigen binding domain, such as CDRs. The same hold true for cases when specification discloses a large pool of antibodies, which are capable to bind a target and have different CDRs. The corresponding claim may relate to all antibodies altogether that are listed as alternatives.
The situation in the EAPO is a little different. According to the current practice when examples disclose amino acid sequences of antibodies, as a rule, it is requested to reflect this information in claims. This is because the above stated provisions of the EAPO related to antibody characteristics in claims is allowable for equivocation and it could be concluded that antibody can be characterized with “other feature” only when its structure is not revealed. However, the EAPO may consider whether a specification proves that many different antibody to a target antigen were obtained, and whether all of them show the desired effect. Therefore, still it is possible to avoid restricting an antibody claim to antibodies of concrete amino acid sequences in the EAPO, drawing the Examiner’s attention to the amount and nature of supporting information provided in the specification of an application. Nevertheless, it may be requested to restrict the claim further by other features such as features of a production method and/or physical and chemical properties.
As it can be judged from the above, both the RUPTO and the EAPO usually accept an antibody claim where a biological function or activity of an antibody is indicated together with its amino acid sequence responsible for this biological function or activity, such as its 6 CDRs
However, CDRs in claims may be defined not only with indication of their sequences, but e.g. like “comprising CDRs from a variable chain of a sequence SEQ ID NO: …” with or without a reference to any scheme of numbering amino acid residues in antibodies. Usually, but not always, in such situation it is requested to indicate a numbering scheme in a claim since, CDRs depend on the applied numbering scheme.
The next problematic situation that should be mentioned in connection with CDRs is when not all 6 CDRs are indicated in a claim, or when a provided characteristic allows some degree of variability in CDRs.
Such characteristic is usually not allowed in both offices. Only in cases when an application contains sufficient body of experimental data, confirming that e.g. CDR variability does not change antibody’s functionality, than such claim may be accepted.
Characterizing antibody by Fc region and its modifications
Some inventions relate to modifications of Fc region in order to improve antibodies properties, such as its effector function. In recent practice of the RUPTO a claim characterizing an antibody only by an Fc region modification and an effect of this modification is not allowed. In articles written by examiners of the RUPTO this position is explained by that Russian patent legislation requires that an antibody claim must state an intended use that can be related only with antigen binding activity but not with an effect of Fc region modification. Therefore, it is declared that essential features of such objects are antigen binding specificity and features that determine it. As a result, such inventions are usually limited to antibodies from examples section with specific antigen binding activity and concrete CDRs sequences.
It is worth noting that a method claim may be a good alternative to an antibody claim if an invention relates to modifications of Fc region since method claim may offer protection to a product produced by such method i.e. an antibody.
The EAPO may be more favorable in respect of inventions related to antibodies characterized by modification(s) of Fc region. However, as a rule, examiners of the EAPO pay much attention to supporting information comprised in the specification of an application while evaluating whether an invention is generally applicable to antibodies regardless of an antigen binding capability.
Characterizing antibody by process of production
As we have indicated above, in claims that characterize antibody’s “other” features (e.g. a production method) have to be combined with physical and chemical properties, such as a dissociation constant of an antibody and its antigen. Usually, RUPTO or EAPO examiners do not dispute whether given characteristic of physical and chemical properties are justified considering the data provided. However, values of parameters reflecting such properties depend on a measurement method and conditions. Therefore, for evaluation of protection scope the specification of an application should disclose how exactly this parameter was determined.
Although provisions related to an antibody characteristic in claims are very similar in the RUPTO and the EAPO, the EAPO is more loyal to an antibody claim characterizing this product only by features of a method without its physical and chemical properties.
Both RUPTO and the EAPO have been changing approaches to evaluation of antibody inventions, so we expect that the trend would continue since interest in antibody patent protection remains quite high. We cannot predict whether these patent offices will coordinate their efforts in improvement of legislation relating to biotech inventions patenting or each of the offices will follow its own path. Nevertheless nowadays, it makes sense to use the difference in the EAPO and the RUPTO approaches to obtain optimal protection for an antibody invention or even to file both Russian and Eurasian patent applications in complex cases.