EPO: Proving plausibility before the EPO

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2025

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

EPO: Proving plausibility before the EPO

A common dilemma for inventors and applicants before the European Patent Office is whether an invention is sufficiently mature for a patent application to be filed. Although a proof-of-concept is often established at the date of filing, an inventor does not always have the opportunity to investigate every aspect of their invention before a patent is filed.

Typically, the EPO has been more relaxed than the USPTO or SIPO regarding this issue, and if an applicant at the EPO encounters an objection that a particular aspect of a claimed invention is not sufficiently disclosed, such an objection can typically be overcome by providing experimental evidence to the EPO that the aspect in question actually works as proposed. Experimental evidence of this nature can be post-published, i.e. the patent application can be supported by experiments carried out after the filing date.

EPO case law requires in principle that a patent claim should be examined for compliance with the requirements of sufficient disclosure (Article 83 EPC) on the basis of the application documents as originally filed. In practice, however, this requirement has not been strictly applied, and patents and patent applications often survive objections of lack of sufficiency, especially if post-published data can be provided.

Some recent decisions of the EPO Boards of Appeal in the pharmaceutical field have developed the existing case law around how plausible the technical effect of an invention must be at the filing date of the patent application.

In decisions T 0488/16 (Dasatinib I) and T 0950/13 (Dasatinib II), the Board required that the technical problem underlying the invention was at least plausibly solved at the filing date. This required technical evidence if the effect is "neither self-evident nor predictable or based on a conclusive theoretical concept". Post-filed evidence and declarations by experts that the products did in fact work as envisaged were not sufficient, and the patents were deemed to lack inventive step.

Decision T 2500/12 (Alzheimer) concerned an immunogen for a pharmaceutical composition in the accepted second-medical use form (for use in the treatment, prevention or amelioration in an animal of Alzheimer's disease or other diseases characterised by amyloid deposits). The Board was not convinced that the suitability of the immunogen claimed for the particular treatment was shown in the application as filed, or in the prior art. The patent claim was found to be insufficiently disclosed.

If these decisions form part of a trend, obtaining valid patent claims on the more speculative aspects of an invention may prove to be more difficult before the EPO.

Edward J Farrington

Inspicos A/S

Kogle Allé 2

DK-2970 Hoersholm

Copenhagen, Denmark

Tel: +45 7070 2422

Fax: +45 7070 2423

info@inspicos.com

www.inspicos.com

more from across site and SHARED ros bottom lb

More from across our site

A $110 million US verdict against Apple and an appellate order staying a $39 million trademark infringement finding against Amazon were also among the top talking points
Attorneys are watching how AI affects trademark registrations and whether a SCOTUS ruling from last year will have broader free speech implications
Patent lawyers explain why they will be keeping an eye on the implications of a pharma case and on changes at the USPTO in the second half of 2025
The insensitive reaction to a UK politician crying on TV proves we have a long way to go before we can say we are tackling workplace wellbeing
Adrian Percer says he was impressed by the firm’s work on billion-dollar cases as well as its culture
In our latest interview with women IP leaders, Catherine Bonner at Murgitroyd discusses technology, training, and teaching
Developments included an update in the VAR dispute between Ballinno and UEFA, the latest CMS updates, and a swathe of market moves
The LMG Life Sciences Americas Awards is thrilled to present the 2025 shortlist
A new order has brought the total security awarded to a Canadian tech company to $45 million, the highest-ever by an Indian court in an IP case
Andrew Blattman reflects on how IP practices have changed and shares his hopes for increased AI use and better performance on the stock market
Gift this article