Raising the plausibility bar

The inclusion of experimental data in a patent application is important to fulfil the patentability requirements in the major jurisdictions.

In the life sciences, the question of how much experimental evidence to include in a new patent application is particularly important as the time required to complete studies, which can be months or even years, conflicts with the first-to-file requirement of all major patent offices.

In Europe, the absence of adequate data can lead to difficulties demonstrating the presence of an inventive step or sufficiency (enablement).

The extent to which an applicant or patentee is entitled to rely on experimental results available only after their patent application was filed (so-called ‘post-published evidence’) varies depending on the country and the issue at hand.

For inventive step objections at the European Patent Office (EPO), it is well established that it is possible to rely on post-published evidence only if the application as filed, together with the common general knowledge, makes it ‘plausible’ that the technical effect is achieved across the entire claim scope.

While patent practitioners generally seek to include as much experimental data as possible, applicants often need to strike a balance with other strategic objectives and commercial goals.

It may sometimes be desirable to withhold key experimental results to maintain a commercial advantage over competitors.

Additionally, results that are obtained through a collaboration may not always be freely available for all parties to use in a patent application.

Previously, applicants might have taken a calculated risk to omit such data from an application, and hope that they can rely upon the data later to demonstrate the existence of an inventive technical effect.

T 0488/16, a recent decision from a Board of Appeal at the EPO, suggests that the bar of ‘plausibility’ has been raised, and thereby limited the situations in which post-published evidence may be considered in an inventive step assessment.

Using post-published evidence at the EPO

It is well-established that the European Patent Convention does not explicitly require a patent application to contain experimental data, either to demonstrate an inventive step or to fulfil the requirements for sufficiency of disclosure and support.

However, it has long been the position of the EPO that an applicant cannot rely on baseless assertions as evidence that a claimed invention gives rise to an advantageous technical effect.

Evidence of that technical effect should ideally be contained in the application itself or in the common general knowledge, but where that is not the case the applicant may be allowed to rely on post-published evidence to support its position.

Decision T 1329/04 is a seminal case on the issue of ‘plausibility’ in the context of inventive step assessment, setting a relatively low ‘plausibility’ threshold for patent applications.

In that case, the claims under examination related to a polynucleotide encoding growth differentiation factor-9 (GDF-9), a new member of the transforming growth factor (TGF) Beta protein family.

The applicant asserted that the claimed polynucleotide solved the problem of providing a new TGF-Beta family member, but the application did not contain experimental evidence showing that GDF-9 functioned as a TGF-Beta protein.

The applicant tried to overcome this by relying on post-published evidence demonstrating the function of GDF-9, but the board refused to consider it.

Critical to this decision was the lack of structural similarity between GDF-9 and known TGF-Beta family members; GDF-9 had only 34% homology with the most similar known TGF-Beta and lacked key structural features.

In light of these structural differences, the board found that it was not plausible that GDF-9 would function as a TGF-Beta protein, and the application was refused for lack of inventive step.

A counter example to T 1329/04 is T 0428/12, which related to a compound per se that was purported to be a proteasome inhibitor with improved pharmacological properties.

Referring to T 1329/04, the board found that, despite the claimed compound not being exemplified, the application contained pharmacological data demonstrating the function of structurally similar compounds.

Therefore, there was no substantiated doubt on the plausibility that the claimed compound exhibits proteasome inhibitor activity.

A similar decision was made in T 1677/11, in which the facts were distinguished over those in T 1329/04 on the grounds that “concrete technical basis was given for the reservations expressed” regarding plausibility in T 1329/04.