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.
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.