Significantly, the Board of Appeal decided that there was insufficient evidence in the application at the filing date to render plausible the alleged technical effect of the single claimed compound. As a result, post-published data were not taken into consideration for the assessment of inventive step.

Background to T 488/16

EP 1169038 relates to the compound dasatinib, which is approved in the US and the EU for the treatment of chronic myeloid leukaemia (CML). Dasatinib is produced by BMS and sold as Sprycel® with sales of about USD 1.8 billion worldwide.

The significance of this case was well recognised, with third-party submissions made by the European Federation of Pharmaceutical Industries and Associations (EFPIA) due to the potential impact on patenting in the life sciences.

Patent EP 1169038

EP 1169038 was filed in April 2000 and disclosed a very broad genus of compounds defined by a Markush formula. In addition, the application disclosed 580 synthetic examples falling within the scope of the broad general formula, which included dasatinib. The sole claim of the only request under consideration by the Board of Appeal related to the compound dasatinib, defined by its chemical structure, or salts thereof.

The original application disclosed a number of protein tyrosine kinases (PTKs) as potential inhibitory targets of the disclosed compounds, and generically described assays that are suitable for ascertaining the activity of a compound as a PTK inhibitor.

Crucially, however, the application did not disclose any data as evidence of the PTK inhibitory activity of any of the compounds encompassed by the general formula, let alone dasatinib itself. Instead, the only support for such activity was the statement that: “Compounds described in the following Examples have been tested in one or more of these assays and shown to have activity”.

As was not uncommon practice at the filing date, BMS appeared to have been in possession of data, but chose not to include this in the application.

Plausibility and inventive step

The patentee argued that there is no requirement in the European Patent Convention (EPC) to include data in an application, and that the statement in the application confirming the inhibitory activity of compounds of the examples, along with the well-known assays that could be used to assess activity, made it plausible that the technical effect was solved and that this could be readily verified.

The patentee also filed post-published evidence, which it was argued demonstrated that dasatinib was an improved PTK inhibitor compared to the prior art. In the patentee’s view, this proved inventive step.

The Board of Appeal disagreed. Although agreeing that experimental data are not always required, the Board of Appeal reasoned that if the invention relies on a technical effect that is “not self-evident nor predictable or based on a conclusive theoretical concept” some evidence must be provided at the filing date to show that a technical problem has been solved. A “mere verbal statement” was not sufficient. The Board of Appeal stated: “it is not acceptable to draw up a generic formula, which covers millions of compounds, vaguely indicate an “activity” against PTKs and leave it to the imagination of the skilled reader or to future investigations to establish which compound inhibits which kinase and is therefore suitable to treat the respective diseases associated therewith”.

Conclusion of the Board of Appeal

In the Board of Appeal’s view, plausibility had not been demonstrated at the filing date, thus post-published evidence could not be considered. Applying established case law the Board of Appeal then concluded that the claim of the main request lacked inventive step, because it only provided a new structure that did not show any effect.

Referral to the Enlarged Board of Appeal

Requests by the patentee to refer questions to the Enlarged Board of Appeal were rejected. The Board of Appeal reasoned that the questions were primarily technical questions answered in view of the facts and evidence of the case, and that questions relating to plausibility cannot be answered in general, but are case-specific.

Lessons for patent applicants

This decision emphasises the importance of establishing plausibility at the filing date. Although data not included but shown to have been generated before filing might hold some persuasive value, applicants should aim to include as much experimental data as possible relating to the primary technical effect and not rely solely on general statements. Including data substantiating other technical effects, such as solubility and toxicity, might also prove beneficial.

Case details at a glance

Jurisdiction: European Patent Office
Decision level: Board of Appeal
Parties: Bristol-Myers Squibb Holdings Ireland (applicant), Isenbruck Bösl Hörschler LLP, APOTEX INC., Actavis Group PTC ehf and Generics [UK] Limited (opponents)
Date: 01 February 2017
Citation: T 488/16
Decision(PDF): http://dycip.com/t048816