Top 10 Observations on the European Patent Office’s Problem Solution Test

As is well known, the European Patent Office (EPO) uses the problem solution test to evaluate inventive step.  The test has 3 steps:

– determining the closest prior art

– establishing the objective technical problem to be solved

– considering whether the claimed invention, starting from the closest prior art and the objective technical problem would have been obvious to the skilled person.

The test has more subtleties than one would imagine.  Here are our observations:

1. What is the Correct Technical Problem?

Choosing the correct technical problem is sometimes crucial to convincing an Examiner that the claims have inventive step. Ensure that that all of the technical advantages are represented in the problem as best as possible.  For example where the invention is a new gene the problem could be stated:

a) providing a novel gene

b) providing a gene that encodes a protein with X activity

c) providing a gene encoding a protein with X activity, the modulation of which can be used to treat condition Z

Clearly it will be easier to show that the prior art does not suggest (c) versus showing it does not suggest (a).  In general narrowly defined problems are advantageous in examination.

2. What is the Correct Closest Prior Art?

Ensure that the correct closest prior art is chosen, because that will define the problem.  Hindsight based on the invention can lead to an incorrect choice of closest prior art, and if that happens it should be pointed out to the Examiner.  In particular it should be borne in mind that the search is performed using knowledge of the invention.  Again if it is felt that the cited documents would not have been identified by the skilled person without hindsight then this should be used in inventive step arguments.

3. Is Recognition of the Problem Part of the Contribution?

Do not assume that the objective technical problem would have been recognised by the skilled person when looking at the closest prior art.  For example if the invention concerns minimising the side effects of a drug, unless the side effects are recognised the prior art, then identifying the side effects themselves is part of the contribution made by the invention, and that must be appreciated when inventive step is evaluated.

4.  Should the Application Refer to the Problem Which is Solved?

When drafting an application is not always clear as to whether one should define the problem being solved.  This is seen by some as a sort of admission which could disadvantage them if the prior art situation changed.  We believe a lot of caution is needed when drafting, and it is better to define ‘contributions’ made by the invention which reflect the different advantages.  Broad and narrow contributions can be defined which will assist with defining a problem during examination, but these should be written bearing in mind that the problem often changes as new prior art is identified in the search.

5.  Should the Claims Refer to the Technical Effect When it is Not a Limiting Feature?

This is a more subtle point than it would first appear.  The technical effect allows the problem to be solved, and so it must be fully appreciated when evaluating inventive step.  The following claims can have the same scope:

a) Compound X with formula Y

b) An inhibitor of crystallisation X, with formula Y

However the contribution is much more apparent from the way (b) is written.  Given that success in examination can often be determined by how much the Examiner appreciates the technical effect, including the technical effect within the claims can be advantageous.

6. The Application Needs to Show That the Problem has been Solved

When drafting, thought should be given to which problems have been shown to be solved by the available data, and whether there is a risk that an Examiner will consider the problem not to have solved.  This can happen in the situation where a compound is alleged to have therapeutic activity based on in vitro data.  Alternative problems should be considered, and basis should be provided for limiting to those problems.  In the case of a vaccine an Examiner may object that ‘protection’ against the condition has not been demonstrated, but may accept a claim which refers to ‘stimulating an immune response’ without requiring protection to be achieved.  The application should provide the flexibility to see the technical effect in different ways, allowing the problem and the invention to be defined in different ways.

7.  The Plausibility Test

The EPO may use the plausibility test when there is doubt about whether the technical problem has been solved.  It evaluates whether it is ‘plausible’ that the problem has been solved based on the content of the application, and so the Examiner may exclude additional data or documents from the analysis.  That means that when one is drafting in a situation where there may not be enough data one must take care to explain within the application how the data shows the problem has been solved.

8. Don’t Undersell the Problem which has been Solved

When drafting the application, one must not be too critical of the contribution that has been made.  A reasonable level of extrapolation can be done based on the technical effect which has been achieved.  If a compound has been found to reduce viral growth, then it is reasonable to claim the compound for use in treating conditions caused by the virus, and perhaps also conditions caused by related viruses.  One must not allow an over-critical approach to impact the drafting in a way that makes the invention look less impressive.

9. Choice of the Technical Problem in Opposition

Bear in mind when attacking a patent in opposition it is generally advantageous to define the problem more broadly.  A problem could be defined in the following two ways:

a) providing a new gene

b) providing a new gene which is the basis of pancreatic cancer

Problem (a) looks less impressive, and this more broadly defined problem could allow more prior art documents to become relevant to inventive step, and make it easier to show that the invention can be derived from the prior art.  When looking to define the problem the data in the patent under attack should be looked at in a very critical way.

10. Different Problems May be Solved for Different Claims

Bear in mind that the problem solved by the first claim may dominate the evaluation of inventive step.  Therefore thought should be given as to how the claims should be ordered to best present the invention.


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