This is the third part of our three-part article on EPO Enlarged Board of Appeal referral G 2/21. Here, we take a deep dive into the case law for those looking for the detail, and include insights that can be gleaned from historical decisions on this area of law. Part I provides a five-minute summary of what you need to know (in a hurry), followed by practical implications for attorneys and applicants to help ensure applications are (plausibly) fit-for-filing and prosecution before the EPO. Part II is an analysis of the technical/legal facts of the appeal behind G 2/21 and provides a digest of post-filed data/plausibility issues in practice.
Plausibility isn't mentioned or defined in European statutory law
As mentioned in part I of this article, the European Patent Convention (EPC) contains certain safeguards against entirely speculative patent applications for so-called "armchair inventions". These include:
- Article 83 EPC – sufficiency of disclosure (a skilled person reading the application as filed should be able to carry out the invention without further help/information);
- Article 57 EPC – industrial application (the application must relate to an invention that can be made/used in industry – this is particularly applicable to gene inventions);
- Article 52 EPC – patentable inventions (some things cannot be classed as an invention, e.g. discoveries and scientific theories); and
- Article 123(2) EPC – amendments (an application cannot be amended to add subject matter which goes beyond the application as filed, e.g. adding a scientific rationale for your proposed technical effect after filing).
Over time, the EPO has also adopted a stance that technical effects/advantages must be at least plausibly demonstrated in a patent application as originally filed. Otherwise, objections under Article 56 EPC (inventive step) or Article 83 EPC (sufficiency of disclosure) may be raised. However, the term "plausibility" does not actually appear in the Rules and Articles of the EPC, whether in Articles 56 or 83 EPC or otherwise. Instead, the term has emerged from the last few decades of case law. This section takes us back to where it all began and provides insights into its subtleties.
Three key early decisions
(i) The dawn of the plausibility hurdle in Europe: T 939/92 (AgrEvo, 1995)
Those familiar with this topic will know that the concept of
plausibility is considered to originate from EPO Board of Appeal
decision T 939/92, AgrEvo, although the word
"plausible" doesn't actually appear in this
decision.
In AgrEvo, claim 1 of European patent application no. 87303463.1 related to broad range of triazole
compounds which were allegedly useful as herbicides. At first
instance, the EPO Examining Division found that the scope of the
claims did not represent a reasonable generalisation of the
examples provided in the description because only around 30
compounds were tested for their herbicidal activity, whereas the
claims defined a genus protecting millions of compounds.
On appeal, this opinion was shared by the EPO Technical Board of
Appeal (TBA). The decision made reference to the quid pro
quo principle that the extent of a patent monopoly should
correspond to its technical contribution to the art – here it
was determined that the scope of protection granted was too broad.
Although the TBA invited the applicant to either restrict the
claims to compounds which were credibly herbicidal or provide
further evidence of wider herbicidal activity (Reasons 2.6.7), the
applicant did not oblige and the application was refused (finally,
with no further option of appeal).
In Europe, inventive step is assessed using the
"problem-solution" approach. As part of this test, a
solution to an underlying technical problem must be achieved across
the whole scope of the claims. In AgrEvo, this meant that
the applicant needed to demonstrate that it was "credible that
substantially all claimed compounds possessed this [(herbicidal)]
activity" (Reasons 2.6). However, the TBA in this decision
therefore concluded that, since the applicant could only
demonstrate that some of the claimed compounds possessed
herbicidal activity, inventive step could not be acknowledged
across the whole scope of the claim.
The underlying result of this decision is that it must be
credible that a technical effect is achieved across the
whole scope of the claims. This result has been frequently invoked
by European examiners, opponents and boards of appeal.
(ii) Plausibility in terms of sufficiency of disclosure: T 609/02 (Salk Institute, 2004)
In this seminal decision, a key claim of the patent at issue (EP0552202, claim 6) related to the use of an
active agent for the preparation of a pharmaceutical for use in the
treatment of arthritis and other disorders (i.e. a
Swiss-type medical use claim). In Europe, the medical indication in
such claims is interpreted as a functional feature.
However, the TBA determined that the application as filed provided
no evidence that this functional feature was actually achieved,
e.g. there were no data or information in the application
as filed demonstrating the impact of the agent on the listed
diseases.
The patentee filed post-filed data (also known as post-published
data) in support of this effect. However, the TBA concluded that
the application as filed provided only a "vague indication of
a possible medical use" and that "later more detailed
evidence cannot be used to remedy the fundamental insufficiency of
disclosure of such subject-matter" (see decision Reasons
13).
In other words, applying the principles of AgrEvo, it
wasn't made credible in the application as filed that the
active agent could treat the diseases in the claim. Since the
technical effect (the medical use) appeared in the claim,
plausibility was raised here in the context of sufficiency of
disclosure. As with AgrEvo, this result has been
frequently invoked by European examiners, opponents and boards of
appeal.
(iii) Plausibility in terms of inventive step: T 1329/04 (Johns Hopkins, 2005)
This decision is credited for entering the term
"plausibility" into European patent law (and,
incidentally, was handled by Kilburn & Strode).
The patent application in question (European application no. 94907259.9) related to a novel polypeptide
which, according to the application as filed, belonged to a
superfamily of compounds known to be important in embryonic
development (the compounds behave as growth differentiation
factors). No data relating to the functional role of the novel
polypeptide were included, although it was suggested that the
polypeptide could have either a stimulatory or an inhibitory role
in the ovary, where it was shown to be located.
However, the TBA highlighted that the novel polypeptide did not
exhibit what the TBA described as "the most striking
structural feature" of the compound superfamily (a specific
pattern of cysteine residues) and raised doubts that the novel
polypeptide would truly be a growth differentiation factor in the
same way as previously-known members of the superfamily.
The TBA concluded that inventive step could not be acknowledged
because there was not enough evidence in the application as filed
to "make at least plausiblethat a solution was found to
the problem which was purportedly solved" (Reasons 11,
emphasis added). Here, the problem to be solved was the provision
of a further member of the superfamily.
The applicant submitted post-filed data showing that the
polypeptide played a functional role similar to others in the
superfamily and was indeed a growth differentiation factor, despite
lacking the characteristic structural pattern with stimulatory
effects on the ovary. However, these data were not considered by
the TBA since they were deemed to be "the first disclosures
going beyond speculation" that the polypeptide belonged to the
superfamily. The application was refused (finally, with no further
option of appeal).
The TBA in this decision mirrored the T 609/02 TBA's adoption
of the ab initio plausibility standard, stating that
post-filed data "may not serve as the sole basis to establish
that the application solves indeed the problem it purports to
solve" (Reasons 12).
As with AgrEvo, the Johns Hopkins test is also
often cited when determining whether or not post-filed data can be
admitted into proceedings.
Back to G 2/21: EPO case law since Johns Hopkins
G 2/21 stems from EPO TBA opposition T 116/18. Here, the referring TBA considers
there to be three diverging branches of case law, corresponding to
the three possible standards discussed in the first and second
parts of this article (the "ab initio
plausibility" standard, the "ab initio
implausibility" standard and the no plausibility
standard).
The "ab initio plausibility" branch centres
around T 1329/04 (Johns Hopkins) and T 609/02 (Salk
Institute) described above. Other examples given are T 488/16 (part of the Dasatinib
trilogy), T 415/11, T 895/13 and T 1791/11. The referring TBA notes that these
cases did not allow post-filed data into proceedings because the
respective applications as filed did not make the technical
effect/advantage plausible.
In the "ab initio implausibility" branch, the
referring TBA cites T 536/07, T 1437/07, T 578/06, T 266/10, T 863/12, T 919/15, T 184/16 and T 2015/20 as examples. According to the
referring TBA, these cases did allow post-filed data into
proceedings because, although there was arguably not enough
information that demonstrated the technical effect/advantage was
plausible, there were no legitimate reasons at the time of filing
to doubt that the technical effect/advantage was plausible. In
other words, there were no legitimate reasons to consider that the
technical effect/advantage was implausible.
Under the "no plausibility" branch, the referring TBA
cites only two decisions: T 2371/13 and T 31/18. In these cases, the notion of
plausibility was rejected because this was considered to be
incompatible with the problem-solution approach.
The examples cited by the TBA in these three branches include cases
of both inventive step plausibility and sufficiency plausibility
(the distinction between these is discussed in part II of this
article). However, the preliminary opinion of the EBA indicates that
the G 2/21 decision will not comment on sufficiency
plausibility. We therefore expect EPO practice towards cases of
sufficiency plausibility to continue on a case-by-case basis, using
precedent set by the seminal T 609/02 (Salk Institute)
case and later cases.
It remains to be seen which standard for inventive step
plausibility the EBA will adopt in G 2/21. For practical tips on
ensuring applications are (plausibly) fit-for-filing and
prosecution before the EPO, please see part I. For a full digest of the facts at
issue in G 2/21 and how the EBA's decision could determine the
validity of the patent in question, please see part II.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.