When drafting a patent specification, it is crucial to consider where it may eventually be filed and prosecuted globally. Claim types that are allowable in one territory may not be allowable in others. Additionally, passages of the description that may serve as valid basis for an amendment in some countries may be objected to in others.

Without careful thought, important subject matter can be lost during prosecution resulting in claims of restricted scope and of limited commercial use. Furthermore, longer prosecution time required to gain patent protection can lead to increased costs. This article aims to highlight some of the issues that may arise in prosecution outside the US and how they can be mitigated through careful drafting of an application.

Allowable claim types

Different jurisdictions can have quite different laws on what subject matter is patentable and what types of claims are allowed. For instance, claims to business methods are not allowed in Europe, Indonesia, Malaysia and India, but are allowed in China, Japan, Singapore and Korea. Therefore, if working within an area of technology where this is likely to be an issue, it is best to provide language in the specification that could form the basis for other claim types which are allowable.

This is of particular relevance to the pharmaceutical industry, where the majority of territories, including Europe, China and Japan, do not permit claims to methods of treatment or diagnosis performed on the human or animal body. Therefore, claims drafted in this manner will usually need to be reformulated to an allowable format for prosecution abroad.

Consequently, it is advisable to include language in the description on which alternative claim formats can be based, such as first medical use type language (X for use in therapy), EPC 2000-style claim language (X for use in a method of treating condition Y) and “Swiss-type” language (the use of X for the manufacture of a medicament for the treatment of Y), which is still used in some countries (such as Thailand and Singapore). Consideration should also be given to including basis in the description for related claims, for example to pharmaceutical compositions, combinations, administration routes, dosage regimes etc.

It is also possible that such claims may have different interpretations depending on where they are being assessed. For instance, in Singapore (where it is possible to rely on an application allowed in US/EP/AU/JP/KR/GB or CA), EPC 2000-style claims are interpreted as first medical use claims, and any true second medical use claims must be in the Swiss-type form, which is not used in Europe or the US. Therefore, if second medical use claims are important, relying on claims allowed elsewhere which do not include Swiss-type language is not recommended.

There are countries that do not allow claims to a new use or formulation of a known substance (India, Indonesia and the Philippines) unless it can be demonstrated that the claimed form or formulation shows significantly improved bioavailability, efficacy or synergy.

In relation to claims for methods of diagnosis, the easiest way to circumvent any objection is to explicitly state in the description that the method involves an in vitro step on a pre-obtained sample. Claims relating to the obtaining of the sample are likely to be excluded from patentability as methods of surgery in the majority of countries.

Avoiding added subject matter objections

A common problem facing applicants before the EPO, as well as in other territories such as China and Japan, is how to introduce amendments without falling foul of the strict assessment of added subject matter.

The best way to address this when drafting an application is to include as many “fallback” positions as possible, and to discuss these for both individual features and combinations of features. If too few fallbacks are identified, it may be that the only option in prosecution is to limit to a very narrow claim scope which could potentially exclude commercially useful examples.

For instance, if a most preferred peptide comprises serine and is at least 10 amino acids long, then it is prudent to include separate descriptions that start with a broad scope and get progressively narrower for both the identity of the amino acid and the length of the peptide. Equally, if it is envisaged that two features discussed separately could be combined, then it is good practice to include a discussion of the combination in the description.

If the claims rely on features defined by ranges of values, it is advisable to include a number of progressively narrower “nested” ranges focusing in towards the most preferred value. For example, if the most preferred particle average diameter is 20 nm, then ranges detailed in the description could include an average diameter range of from 5 to 50 nm, a preferred range of from 10 to 30 nm, a more preferred range of from 15 to 20 nm and the most preferred average diameter to be about 20 nm.

If a group of features is only discussed together in the description, under European practice amendments made to isolate one particular feature from the group are usually found to add subject matter (“intermediate generalisation”). Similar objections arise when a feature is taken from an example because the feature chosen for the amendment is only disclosed in combination with the other specific features of that example. To avoid this, any features of the examples that are particularly advantageous should be identified separately in the description.

Another way of reducing the likelihood of making intermediate generalisations includes drafting multiply dependent clauses which provide basis for a variety of different combinations of features.

In summary, to provide adequate basis for amendment during prosecution abroad, and to avoid added subject matter objections, ideally the specification should describe several narrower embodiments for each feature and/or combination of features in the claims. If any features present in the examples or figures are of particular importance then these should be highlighted separately in the description.

Considerations relating to sufficiency

During prosecution, sufficiency (enablement), ie whether the specification provides enough information for a skilled person to work the invention, is often one of the first grounds for patentability to be examined. However, how rigorously this criterion is assessed varies from territory to territory. Hence, when preparing a specification, it is prudent to include as much information on how the invention is carried out as commercially possible. Issues often arise when information about a particular aspect of the invention is missing, placing the onus on the applicant to argue and prove to the Examiner that the skilled person would know what to do in the absence of further information in the specification. Clearly, it is much more straightforward to simply ensure that this information is available from the start.

Therefore, to forestall any lack of sufficiency objections, full details of all aspects of the invention should be included in the description.

For example, descriptions of any measurement step mentioned in the description should be included, especially those of properties identified in the claims. This is particularly important for measurements where a number of methods could be used (eg for obtaining particle size) or where the measurement value can be defined in a number of ways (eg polymer molecular weights). References to an industrial standard can be used, but if the parameter being measured is unusual, a full description of the type of instrument, the settings applied and the preparation of the samples should be included.

Similarly, if relevant, the description should provide a clear indication of what starting materials and processing steps are used. For the avoidance of doubt, if materials are referred to by their trade marks it is also good practice to identify and fully define them as well. This will remove any ambiguity and allow the examiner to easily determine whether or not the examples support the claims.

Considerations relating to supporting data and inventive step

It is best to include as much supporting data as possible in the application. This data serves the dual purpose of demonstrating the plausibility of the claimed invention (particularly for pharmaceutical inventions where it is envisaged that the claimed compounds could treat a certain condition) and providing evidence to support inventive step during prosecution. When arguing for inventive step, it is possible to file additional data as evidence in most countries, but the application must be sufficient on filing.

As a result, it is best to wait until at least some proof of concept data is available before filing. In vitro data can be used for this purpose.

In particular, in China, claim scope is strictly tied to the breadth of the supporting examples and post-filed data cannot be used to support the scope (but may be used to substantiate inventive step arguments). Hence, including as much supporting data as possible maximises the chances of achieving a broad claim scope overseas.

Data is crucial in countries where protection for new uses/forms of a known substance is only allowed if significantly improved bioavailability, efficacy or synergy is demonstrated (eg India).

Filing strategies

In view of the above comments on supporting data, if at all possible, usually, it is best to refrain from filing a first (priority) application until sufficient data to demonstrate an inventive step has been collected. It is also good practice to ensure that a priority application is as complete as possible, as priority entitlement is strictly assessed in certain jurisdictions. For instance, in Europe, the test for priority entitlement is the same as that for novelty, ie the priority application must directly and unambiguously disclose the same subject matter as claimed in the later application in order for the claims to be priority entitled.

In most other jurisdictions outside of the United States, continuation-in-part applications are not available. Therefore, any later filed applications with additional subject matter which do not claim priority must be novel (and potentially also inventive) over their earlier counterparts.

One strategy is to file any later application before publication of the earlier application, such that the earlier application is only intermediate “novelty-only” prior art. However, some territories will consider that the earlier application is also citeable for inventive step, therefore, it is best to also have data present in the later application that demonstrates an advantage over the invention of the earlier application.

Plan for later, earlier

With cost constraints looming over most applicants, it can be tempting to cut corners when drafting your first filing in order to reduce professional advice and official fees. However, without consideration of the impact of decisions made during first filing application drafting on a patent application in other jurisdictions, the resulting costs of overseas prosecution can spiral and the scope of the patent protection secured can be limited such that the protection becomes less valuable – whether you plan to manufacture your invention yourself or use the patent right to generate secondary income through licensing or sale.

By planning for prosecution in other jurisdictions from the offset, you can tailor your first filing application to ensure that it optimises your potential maximum protection and sets you up for fruitful future foreign filings.