Plausible or not implausible? When can post-filed data be used to support an inventive step?

One of the EPO’s Boards of Appeal is expected to request clarification from the Enlarged Board of Appeal on the law concerning the doctrine of ‘plausibility’ and the use of post-filed data to support inventive step.

BACKGROUND

Although the concept of plausibility does not appear anywhere in the European Patent Convention, it is becoming increasingly important in the assessment of inventive step and sufficiency, especially in the fields of chemistry and life sciences. Connected with plausibility is the very practical issue of how much data an applicant needs to provide in the application at the time of filing and whether they may subsequently supply additional data (“post-filed data”) to support inventive step and/or sufficiency.

The concept of plausibility stems largely from the landmark decision T1329/04 (Factor-9/Johns Hopkins), in which it was held that a technical effect relied upon by a patentee may only be supported by post-filed data if the effect is at least made plausible in the application as filed. Plausibility itself is not a requirement for patentability, but is a threshold which must be met in order for post-filed data to be taken into account when assessing inventive step and sufficiency.

Following this key decision, the EPO jurisprudence concerning plausibility and the admissibility of post-filed data has grown considerably. The majority of cases in this line of jurisprudence have cemented the position that a technical effect must be made plausible in the application as filed. However, there has been a growing strand of divergent case law, beginning with T0578/06 (Pancreatic Cells/IPSEN), supporting a more liberal approach in which plausibility need only be assessed if there are substantiated doubts that the claimed invention produces the alleged technical effect.

Ultimately, it is this divergence that is prompting the Board of Appeal in T0166/18 to refer questions concerning plausibility and post-filed data to the Enlarged Board of Appeal.

THE FACTS AND ARGUMENTS

The case in question is an appeal against the decision of the EPO’s Opposition Division to maintain Sumitomo Chemical Company’s European patent no. 2484209 as granted following an opposition by Syngenta. A key aspect of the patentee’s inventive step argument relies on a synergistic effect between the two compounds present in the claimed insecticide composition, which was supported by evidence submitted during the opposition proceedings. The appellant counterargued that the synergistic effect was not plausible from the application as filed, with the consequence that the post-filed data should not be taken into consideration.

JUDGMENT

During the oral proceedings, the Board of Appeal indicated that due to the divergence in case law concerning plausibility, it would likely be referring the following (paraphrased) questions to the Enlarged Board of Appeal:

  1. Must post-filed data be disregarded if the proof of a technical effect rests exclusively on those data?
  2. If yes to Q1, can post-filed data be taken into account if the effect is plausible from the application as filed?
  3. If yes to Q1, can post-filed data be taken into account if the effect is not implausible from the application as filed?

The parties will have an opportunity to comment on the draft questions before any formal referral to the Enlarged Board of Appeal.

IMPLICATIONS

The outcome of a referral concerning plausibility and post-filed data could have wide-reaching implications for applicants, particularly in the field of life sciences where data generation can be slow and costly.

Although the wording of the draft questions appears to only permit a relaxation (Question 1 answered no, or Questions 1 and 3 answered yes) or maintenance of current practice (Questions 1 and 2 answered yes), the Enlarged Board of Appeal is at liberty to reformulate the questions as it sees fit, with the consequence that it is possible that the outcome of a referral presents further restrictions on the admissibility of post-filed data supporting inventive step.

It is our view that the EPO is unlikely to lower the bar for admissibility of post-filed data, due to its belief, as explained in T1329/04 and subsequent decisions, in the principles that an applicant should have the invention in hand at the time of filing an application, and is entitled to a scope of protection commensurate with its contribution to the art.

Innovators will, no doubt, hope that the EPO does not significantly raise the bar for admissibility of post-filed data, due to the often significant challenges of obtaining conclusive evidence, particularly clinical trial data, at what is normally an early stage in the development cycle. Furthermore, the EPO’s problem-and-solution approach for assessing inventive step relies on demonstrating a technical effect for the invention relative to the closest prior art. It is common that an applicant will not be aware of the closest prior art at the time of filing an application, and so an obligation to have conclusive data “proving” a technical effect relative to that document in the application at the time of filing could be seen by many as unreasonable.

The precise format of the questions remains to be established, and the wording may yet be altered to ask the Enlarged Board to clarify whether the plausibility (or implausibility) issue is to be assessed based on the information in the priority application.

A tightening up on the admissibility of post-filed data would mean that applicants in the chemistry and life sciences fields may need to consider more carefully whether to delay filing an application until they have obtained further data, or whether to file an application which targets protection more narrowly around their existing data. This consideration is critical, since by definition a lack of plausibility cannot be remedied after filing.

Once a referral has been made to the Enlarged Board of Appeal, there is typically a delay of one to two years before a decision is issued. For pending applications and opposed patents where these issues are likely to be determinative, we expect that the EPO will allow a stay of proceedings pending the outcome of the referral to the Enlarged Board of Appeal.

KEY TAKEAWAYS

The Enlarged Board of Appeal is expected to be asked to clarify the interplay between plausibility and the admissibility of post-filed data for inventive step.
A further tightening of the admissibility of post-filed data will require applicants, especially in the chemistry and life sciences fields, to carefully consider the timing and scope of future patent applications.
For pending applications and opposed patents where the outcome of the referral is likely to be determinative, applicants should request a stay of proceedings pending the Enlarged Board’s decision.