By Fei Sha and Paul A. Calvo, Ph.D.

The Guidelines for Examination in the European Patent Office (EPO) permit the use of post-filing experimental data in a limited manner to support the scope of objected claims. However, reliance on post-filing data differs when claims are objected to for insufficiency of disclosure or lack of inventive step.

Sufficiency of Disclosure

Article 83 of the European Patent Convention (“EPC”) requires European patent applications to “disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.” A single example may suffice, but for claims that cover a broad field, a patent application must disclose multiple examples or describe alternative embodiments or variations extending over the technical area encompassed by the claims. If a patent specification lacks disclosure of tangible proof that the claimed concept can be put into practice, post-published documents can confirm the teachings of a patent application, but cannot be used to “cure” an insufficiency in disclosure.[1]

For example, if a patent disclosure provides no guidance as to how to perform a particular aspect of a claimed invention, post-published documents that later show how such performance is accomplished cannot “cure” the insufficiency.[2] In addition, if a patent specification provides only a vague indication of possible medical use for a yet-to-be-identified chemical compound, post-published documents containing details as to the identity and medical use of the compound cannot remedy the insufficiency of disclosure.[3] However, where an application lacks such explicit data, but discloses a technical concept that is plausible in view of common general knowledge at the relevant filing date, post-published documents may be used to support sufficiency of disclosure.[4]

Inventive Step

In view of the “problem-and-solution approach” to an inventive step analysis, which determines whether a claimed invention provides a non-obvious solution to a technical problem defined by its closest prior art, the “plausibility test” requires that the claimed invention is made plausible by the disclosure in the patent application and that its teaching indeed solves the technical problem that it purports to solve.[5] To satisfy plausibility, there must be verifiable evidence disclosed in the initial application in the form of experimental data or a structure-activity relationship that makes the activity plausible. Mere assertion in the absence of any data is not sufficient to render plausible the teaching of the patent application.

Post-published evidence that supports the proposition that the invention solves the technical problem that it purports to solve can only be considered when it already appears plausible from the patent disclosure that the problem is indeed solved.[6] For example, claims to broad classes of chemical compounds asserted to have some common technical effect were not inventive because nothing in the patent disclosure demonstrated that the compounds would all have that common technical effect – thus the patent disclosure was found to be implausible.[7] However, absolute proof of the achievement of a technical effect through the highest quality evidence is not required for that effect to be deemed plausible.[8] Whether post-published documents may be allowed to support plausibility is ultimately decided on a case-by-case basis.

Similar to most all other jurisdictions, a plausible technical effect or surprising property of the invention must be present over the full scope of the claims. Such an effect can be demonstrated with data in a comparative test between the claimed invention and its closest prior art, where the effect is convincingly shown to have its origin in a distinguishing feature of the invention as compared to the closest prior art.[9]

[1] Decision T 1205/07 “Adenoviral packaging system/CRUCELL” (Sep. 20, 2011).
[2] Decision T 0497/02 “Insulinotropic hormone/GENERAL HOSPITAL” (May 27, 2004), citing decision T 222/00 “Hemicellulose degradation/VALTION” (Jan. 15, 2003).
[3] Decision T 609/02 “AP-1 complex/SALK INSTITUTE” (Oct. 27, 2004).
[4] Decision T 0950/13 “Dasatinib in the treatment of chronic myelogenous leukemia/BRISTOL” (Feb. 03, 2017), citing decision T 1262/04 “Light detection in mammals/LELAND STANFORD” (Mar. 07, 2007).
[5] Decision T 1329/04 “Factor 9/JOHN HOPKINS” (June 28, 2005).
[6] Decision T 0488/16 “Dasatinib/BRISTOL-MYERS SQUIBB” (Feb. 01, 2017); see also CLBA I.D, 4.6.
[7] Decision T 0939/92 “Triazoles/AGREVO” (Sep. 12, 1995); see EPC Art. 56.
[8] Decision T 0716/08 “Infectious salmon anaemia virus vaccine/INTERVET” (Aug. 19, 2010).
[9] Decision T 1009/12 (Jan. 08, 2013); see also CLBA I.D, 10.9.

This article appeared in the September 2019 issue of Global Patent Prosecution.