Reach-through claims

Reach-through claims

This article explains what a “reach-through” claim is and then discusses the patentability of reach-through claims. The patentability of reach-through claims has particular importance for the protection of fundamental research which could be used in the subsequent development of biological or chemical therapeutic entities. This topic is important not just in terms of the protection of fundamental research inventions in these areas, but is also important in terms of assessing freedom to operate in these areas.

What is a reach-through claim?

Claims are the part of a patent application which set out the scope of protection which is sought. In a granted patent, the claims set out the scope of the monopoly given by the patent. For example, if an inventor discovers a new chemical entity which can be applied to the treatment of disease, they can usually claim some or all of: the chemical entity per se, the chemical entity for use as a medicament, use of the chemical entity for the manufacture of a medicament for a specified therapeutic application and a method of manufacturing the new chemical entity.

Reach-through claims seek to protect things which have not yet been discovered by an inventor, but which might be discovered in the future by making use of their invention. When an invention is made in a widely applicable basic research technology (referred to herein as an “upstream” technology), it is often possible to envisage future technologies (referred to as “downstream” technology) which might be developed using the basic research technology. If the inventor of an upstream invention files a patent application for the upstream invention and attempts to claim downstream inventions which they have not as yet actually made, then the claims to those downstream inventions are referred to as “reach-through” claims.

For example, someone who discovers a new protein which might be suitable for use as a drug target may not be satisfied to obtain protection only for the isolated drug target and methods of screening for drugs which act as inhibitors or agonists (as appropriate) for that drug target. They may also want to obtain explicit protection for all drugs which act as inhibitors or agonists (as appropriate) for that drug target (or all gene therapies which modulate levels of the protein in vivo). Someone who discovers a drug screening process may wish to claim all drugs discovered through that process. The devisor of a peptide-display library or a new combinatorial chemistry technique may wish to protect specific molecules within the library that are later found to have practical applications. In these cases, the inventor would like to reach-through from their invention to protect other products which could follow on from performing their invention, but which they have not as yet actually discovered.

Reach-through claims should not be confused with conventional process claims. Process (or method) claims protect a procedure for making a product, for example an industrial process for manufacturing a drug. Process claims of a patent in force in an EU country are infringed by carrying out the patented process in that country or by certain dealings in (including importing) a product obtained directly by means of the process. To make more product using a patented process requires ongoing use of the process. However, reach-through claims seek to protect downstream products which have been discovered by using a patented upstream process (perhaps only once) or which fulfil certain functionally defined criteria, but are then manufactured by a completely different process.

Issues affecting the patentability of reach-through claims

In this article, we will focus on the European law relating to reach-through claims. Of course, patent law varies between jurisdictions and patent applications must be drafted with a global perspective. Nevertheless, when the European Patent Office, United States Patent Office and Japanese Patent Office carried out a joint project to compare their treatment of reach-through claims in 2001, they came to broadly the same conclusions as to the patentability of claims which they studied.

Several of the requirements of the European Patent Convention governing patentability have specific implications for reach-through claims, in particular the requirements for (1) novelty and inventive step, (2) industrial application, (3) sufficient disclosure, (4) the claims to be supported by the description, and (5) the claims to be clear and concise. These will now be discussed in turn.

1. Novelty and inventive step

The requirement that an invention claimed in a European patent must be both novel and involve an inventive step applies to reach-through claims in the same way as conventional claims. A claim to a downstream product is not automatically rendered novel and inventive simply because it has been discovered through a novel and inventive upstream process.

When a reach-through claim encompasses a group of as yet unidentified biological or chemical entities, it is vulnerable to the risk that some of the group of the as yet unknown entities will turn out to already be known, depriving the claim of novelty and/or inventive step. This risk can be reduced if some work has already been done to characterise some specific identified entities, so that claims can be directed to more defined groups of entities which are less likely to inadvertently include entities that are already known.

Another issue which is particularly relevant in Europe results from the European approach to evaluating inventive step. The presence of an inventive step is determined by considering the objective technical problem (derivable from the patent application) to be solved by the claimed invention. It is therefore important to include credible information in a patent application about problems which might be solved by claimed products and methods. If an inventive screening process may be used to discover new drugs, then in order to have any prospects of obtaining protection for the potential drugs, a patent application should discuss the problems to be solved by the potential drugs, not just the problems solved by the screening process.

2. Industrial application

An invention claimed in a European patent must be susceptible of industrial application. Rules states that the way in which the invention is capable of being exploited in industry must be explicitly indicated, when it is not obvious from the description or nature of the invention.

A skilled scientist reading a patent specification describing a drug screening process is likely to find the industrial application of that process to drug screening to be obvious. However, the industrial application of a reach-through claim to an unspecified drug, to be discovered later by making use of that process, may not be obvious at all.

This means that, in order to help obtain patent protection, the specification of a patent application should contain as much information as possible about the potential industrial application of all claimed subject matter. It is necessary to think ahead as to what might be discovered and how it may be used in industry, and to include this information in the patent application.

The requirement of susceptibility to industrial application presents a substantial obstacle to reach-through claims. The European Patent Office may simply argue that a chemical or biological entity which has not been disclosed in the patent application, even in general terms, is incapable of industrial application.

The subject of susceptibility to industrial application is of broad importance for biotechnology and pharmaceutical patents as methods of treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body are not regarded as inventions which are susceptible of industrial application. This limitation, which is construed narrowly, is a complex topic beyond the scope of this article.

3. Sufficient disclosure

A European patent application must disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. This means that, using the information specified in a European patent application, documents mentioned in the application and the common general knowledge of workers in the field, it must be possible for other skilled workers to perform the claimed invention (over the whole area claimed) without undue burden and without needing inventive skill.

A reach-through claim to a group of biological or chemical entities may lack sufficient disclosure if insufficient examples of such entities are given or if it is not clear how to make and use such entities in an industrially applicable way. Furthermore, a patent application including reach-through claims may lack sufficient disclosure if there would be an undue burden on others who would need to screen a large or potentially infinite number of biological or chemical entities to establish those which could be used in the claimed invention.

As downstream research is carried out to discover biological or chemical entities which fulfil desired criteria, it will gradually become possible to provide more detailed disclosure of specific entities and group of entities which have potential industrial application. As information cannot be added to a patent application once it has been filed, it can therefore be important to think carefully about when it will be possible to provide sufficient disclosure to sustain broad patent claims, and to time the filing of patent applications accordingly.

Objections of a lack of sufficient disclosure can also be raised to reach-through claims which define problems rather than provide technical solutions to problems. For example, someone who discovers a new pathogen and thereby appreciates that treatment of disease caused by that pathogen is a new problem to be solved is unlikely to obtain broad claims to all cures for diseases caused by that pathogen. Just because they have discovered a new problem (curing the disease caused by the pathogen) does not entitle them to protection beyond the actual inventive contribution which they have made and disclosed in their patent application.

4. Support by the description

The claims of European Patents must also be supported by the description contained in the patent application. This means that the scope of claims must be restricted to the scope justified by the invention which has been made. Applicants should be allowed to cover all modifications, equivalents to and uses of the invention which they have described and an invention which opens up a new field is often entitled to make more general claims than an invention which incrementally improves a known technology. Nevertheless, claims cannot generally be extended beyond the invention which has actually been made to cover further inventions which might be made in the future, by using the technology described in the patent application, but which have not yet been made.

As mentioned above, it is important to think carefully about what claims can be supported by research to date before filing a patent application, and to time the filing of patent applications accordingly.

5. Clarity

The European Patent Convention requires that claims shall be clear and concise. Reach-through claims would be unclear if a person reading the claims cannot easily work out what is or is not covered by the claim. The problem of a lack of clarity can be reduced once downstream research starts to make it possible to frame more specific claims to more clearly defined groups of entities.

University of Rochester

There have not, to our knowledge, been any cases decided to date in the UK courts concerning the patentability of reach-through claims. This is evidence of the resistance of the UK and European Patent Offices to granting reach-through claims. For examples of how reach-through claims have fared in court, it is necessary to look abroad.

A good recent example stemmed from the discovery by scientists at the University of Rochester, in the United States, that there were two separate cyclooxygenase enzymes, PGHS-1 and PGHS-2 (also known as Cox-1 and Cox-2) which are produced in the human body and are involved in controlling levels of prostaglandin hormones. They discovered that raised levels of PGHS-1 lead to the production of prostaglandins which are beneficial and help protect the stomach lining. Raised levels of PGHS-2 lead, however, to the production of prostaglandins which cause pain and inflammation. Anti-inflammatory drugs in use when this discovery was made, in the early 1990s, did not differentiate between PGHS-1 and PGHS-2 and acted to inhibit the activity of both molecules. They had the effect of reducing pain and inflammation resulting from the action of PGHS-2 but also reduced levels of beneficial prostaglandins mediated by PGHS-1.

The scientists at the University of Rochester hypothesised that if PGHS-2 could be inhibited selectively, without inhibiting PGHS-1, then this would provide a method of reducing pain and inflammation without reducing levels of beneficial PGHS-1 mediated prostaglandins. They proposed an assay method to screen drug candidates to discover candidates which have the necessary selectivity. However, they did not include any description of drugs resulting from this assay in their US patent application.

Naturally, the University of Rochester wanted to obtain patent protection not just for the screening method they had devised but for any drugs with the necessary selective inhibition properties.

The University of Rochester achieved issuance of US Patent 6,048,850. Claim 1 of this patent was a broad-reach through claim: “A method of selectively inhibiting PGHS-2 activity in a human host, comprising administering a non-steroidal compound that selectively inhibits activity of the PGHS-2 gene product to a human host in need of such treatment”. This claim attempts to protect non-steroidal compounds which have the functionally defined property of selectively inhibiting activity of the PGHS-2 gene, irrespective of how such non-steroidal compounds were discovered. No examples of usable non-steroidal compounds were described in the patent specification.

The University of Rochester sued several major drug manufacturers in the US courts. The manufacturers counterclaimed that the patent was invalid. On summary judgement, it was ruled that the University of Rochester’s patent failed to meet the US “written description” requirement and the US “enablement” requirement. (These requirements resemble but are perhaps stricter than the European requirements of sufficient disclosure and support by the description, mentioned above.)

The judge explained that in order to satisfy the written description requirement, the specification must describe every element of the claimed invention in sufficient detail so that one of ordinary skill in the art would recognize that the inventor possessed the claimed invention at the time of filing. He concluded that the patent did no more than describe the desired function of the compound called for, and it contained no information by which a person of ordinary skill in the art would understand that the inventors possessed the claimed invention. At best, it simply indicated that one should run tests on a wide spectrum of compounds in the hope that at least one of them will work.

It was also ruled that the University of Rochester’s patent failed to meet US enablement requirements as a person of ordinary skill would have to engage in undue experimentation, with no assurance of success, in order to perform the invention.

The University of Rochester lost the case and the subsequent appeal, and the patent was declared invalid.


Reach-through claims face multiple serious legal objections. As the law stands at the present time, true reach-through claims to inventions which have not yet been made will usually be unpatentable in Europe and throughout much of the world. However, there is a grey area. A small amount of ‘reach-through’ may be possible; for example, the European Patent Office will often accept claims to all monoclonal antibodies having sufficiently precisely defined immune reactivity towards new and inventive antigens.

When an upstream research invention is made, it may be possible to envisage further inventions which could be made in the future as a result of downstream development, but it may be impossible to obtain protection for these downstream developments at that time. However, the situation may change as downstream developments occur. It might in time become possible to provide data which could be used to overcome objections of a lack of support, or lack of sufficient disclosure in a new patent application. The industrial application of potential discoveries may become clear and it may become possible to frame more specific claims. Information about the invention cannot be added to a patent application once it has been filed and so any new data needs to be included in a new patent application. New patent applications should therefore be filed as research progresses. It can also be important to estimate the rate at which research will progress when formulating a patent filing strategy.

One risk (which is sometimes unavoidable) when protecting a developing research programme is that early patent applications can have the effect of depriving later filed patent applications of novelty or inventive step. The extent to which this is a problem depends on the time difference between early and later filed patent applications and the nature of the developments which occur. For example, if a downstream research development is introduced into a patent application for the first time only after the publication date of an upstream research patent application (usually around eighteen months after the priority date), then the invention claimed in the patent application for the downstream research development will need to be novel and have an inventive step over the disclosure of the upstream research patent application.

One risk is that the upstream research patent application does not include sufficient support to obtain broad reach-through claims to potential downstream developments, but does contain enough information to deprive later patent application for downstream developments of novelty and inventive step. Sometimes it is appropriate to delay the filing of a patent application for an upstream research invention while research progresses and provides new information which can be usefully included in the patent application. However, this brings its own risks, not least of which is the risk of new prior art entering the public domain, or third parties filing conflicting patent applications during the period of delay.

As a result, it can be especially important to maintain the confidentiality of upstream research inventions for as long as possible. As with all inventions, any non-confidential disclosure which the inventor (or anyone) makes constitutes prior art against which is judged the patentability of any subject matter introduced to a patent application for the first time after the date of that disclosure. The right to claim priority from a patent application which was filed before the date of that disclosure only relates to the invention disclosed in that earlier patent application, and is construed narrowly in Europe. This means that if a non-confidential disclosure of an upstream research concept is made, the disclosure is likely to make it more difficult, or impossible, to obtain protection not just for subsequent improvements or variations to the upstream research concept, but also for potentially obvious downstream developments which might have been protected if confidentiality had been maintained.

Another reason why confidentiality is especially important for upstream research inventions is that much of the commercial exploitation of inventions in basic research fields, such as drug discovery and the exploitation of drug targets, takes place under a web of licensing agreements incorporating confidentiality clauses. The law of confidential information can apply only to information that is still secret. Inventors of upstream research techniques often seek to gain financial benefits from downstream developments made by their commercialisation partners by the use of “reach-through” licence terms which specify licence fees to be paid dependent on future successes from downstream developments. Licences might also deal with the ownership of downstream developments and the transmission of research results which could help secure patent protection for the upstream concept as well as downstream developments. The enforceability of reach-though licence terms and many other terms which might be included in development agreements is restricted by competition law and so it is important to take early legal advice on licensing, as well as patent issues, when developing a commercialisation strategy for inventions in basic research fields.

The problems facing the patentability of reach-through claims also have important implications for those who are concerned by whether they are free to operate in a particular field, or whether they need to a licence to work a patented invention from a third party. Many patent applications pending before the European Patent Office include reach-through claims which might never be granted. Advice should always be sought concerning the patentability of claims in a pending patent application before assuming that the patent application is likely to lead to grant of a patent with particular scope.

Finally, investors who are considering investing in companies whose patent applications contain reach-through claims should also take advice on the patentability of these claims when they are conducting pre-investment due diligence. Investors should maintain a realistic understanding of the extent to which it is possible for the owners of upstream research technology to profit from downstream developments.

In conclusion, the protection of basic research which is likely to lead to patentable downstream developments in the future is a complex field. The law is not yet mature and may well change within the life of patent applications being filed today. Nevertheless, developers of basic research who consider the issues discussed above early on in the commercialisation of their inventions will be at a significant advantage to those who appreciate the limitations of intellectual property law too late.

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