7.2.3 Evidence of therapeutic effect
In T 2218/16 (gene therapy of motor neuron disorders – scAAV9 vector), the board summarised that, according to the established case law, the provision of evidence in the patent application for a claimed effect was not a prerequisite for patentability, if, based on the data in the patent application/patent, or on common general knowledge, it was plausible that a product (here: scAAV9) was suitable for the claimed therapeutic applications (the decision also contains a detailed summary of the case law on the burden of proof; see the full point 32 of the Reasons).
All kinds of experimental data have been accepted by the boards. It has also been repeatedly emphasised that "it is not always necessary that results of applying the claimed composition in clinical trials, or at least to animals are reported" (T 1273/09 citing T 609/02). Reiteration of the principles and application in T 294/20, which predominantly refers to passages of T 609/02 and discusses the findings of G 2/21.
In T 421/14 (dosage regime involving twice-daily treatment – multiple sclerosis), the claims related to a further medical use. All objections raised by the appellants (opponents) concerned the credibility of the alleged therapeutic efficacy. The respondent relied on the data and analysis of a clinical trial. It was known that only a proportion of patients responded to the treatment. The existence of a population of non-responders was also confirmed by the inventors' own results. In the board's view, the existence of these non-responders was not a reason to find the disclosure insufficient, and the treatment of non-responders did not have to be excluded or disclaimed; that a substantial proportion of patients were non-responders was a common phenomenon.
T 338/10 concerned a claim for a second therapeutic use in which the active ingredient was a "first allergen" and the therapeutic use the treatment or prevention of an allergy caused by a different, second allergen. The board found that there was no experimental data in the patent proving that a first allergen could be used to treat an allergy caused by a different allergen.
In T 1777/12 claims 1 and 10 were medical use claims and related to the use of a PYY agonist in the manufacture of a medicament for treating a metabolic disorder in an obese or overweight subject. Clinical trials are not required to establish suitability. It may suffice that in vitro or in vivo data directly and unambiguously reflect the therapeutic effect on which the claimed therapeutic application relies or, alternatively, that there is an established relationship between the physiological activities of the compound under consideration and the disease in question. The board concluded that the disclosure in the patent demonstrated the suitability of PYY for achieving a beneficial effect in all of the claimed therapeutic applications by reducing weight or weight gain.
A post-published document reporting that no proven effective vaccine against HSV was available did not prove the non-workability of the invented vaccine, since there might have been other reasons, e.g. regulatory reasons, for not producing vaccines according to the invention. Furthermore, for compliance with the requirements of Art. 83 EPC 1973, it was not necessary to undertake and disclose clinical trials (T 1023/02).
For the acceptance of sufficient disclosure of a therapeutic application, it is not always necessary for results of clinical trials to be provided at the relevant date, but the patent/patent application must provide some information showing that the claimed compound has a direct effect on a metabolic mechanism specifically involved in the disease. Once this evidence is available from the patent/patent application, post-published evidence may be taken into account to support the disclosure in the patent application (T 433/05). In T 1045/13 the board agreed with the statements made in T 433/05 and T 801/06, but in case T 1868/16 (suitability of everolismus for treating PNETs), no data or plausible technical concept was present in the patent.
See also T 1210/20 and decisions T 1779/21 and T 979/23 which, besides specifically addressing the particular case of serious diseases (see below), analyses the general statements in G 2/21 regarding evidence.