The EPO practice on selection inventions has developed considerably over the past decade. Two recent decisions of the Technical Board of Appeal are particularly instructive for applicants in the life sciences field.
The Guidelines for Examination in the EPO (EPC Guidelines) define selection inventions as those that "deal with the selection of individual elements, subsets, or sub-ranges from a more generic disclosure in the prior art". The Guidelines address the examination of both novelty and inventive step of selection inventions.
Novelty and inventive step
In terms of novelty, the latest edition of the Guidelines states that a sub-range selected from a broader numerical range is considered novel if two criteria are met:
- the selected sub-range is narrow compared to the known range; and
- the selected sub-range is sufficiently far removed from any specific examples disclosed in the prior art.
The Guidelines add that the meaning of "narrow" and "sufficiently far removed" has to be decided case-by-case. But they provide the following guidance: "In this context, it must be assessed whether the skilled person, in the light of the teaching of the prior art, would seriously contemplate working in the selected sub-range. If it can be fairly assumed that the skilled person would do so, the selected sub-range is not novel. For this reason, it may not be sufficient to exclude specific novelty-destroying values known from the prior-art range to establish novelty."
Prior to 2019, there was a third criteria that "the selected range is not an arbitrary specimen of the prior art". However, this so-called purposive-selective criterion was removed from the Guidelines following the development of Board of Appeal case law. The impact has been to increase predictability for patent applicants, including for inventions in the life sciences sector.
On inventive step, the Guidelines state: "If this selection is connected to a particular technical effect, and if no hints exist leading the skilled person to the selection, then an inventive step is accepted ... For inventive step, it has to be considered whether the skilled person would have made the selection or would have chosen the overlapping range in the expectation of some improvement or advantage. If the answer is negative, then the claimed matter involves an inventive step."
Second medical use patents
We often see selection inventions in the life sciences field, for example where a patent relates to a specific application to a particular treatment but the prior art covers broader applications. Two interesting recent Technical Board of Appeal decisions dealt specifically with patents for second or subsequent medical uses.
The Board's decision in case T 1437/21 concerned a patent that claimed the use of a known drug, empagliflozin, in the treatment of diabetes in a subpopulation of patients. It was filed by Boehringer Ingelheim.
Eight oppositions were filed, mainly by generic companies, and the Opposition Division revoked the patent. It found that it lacked novelty on the basis of press releases published by Boehringer Ingelheim and Eli Lilly concerning the success of a phase III clinical trial in the broader patient population.
However, in its decision in February this year the Board of Appeal considered that the wording of the press releases "may well be understood as relating to the patient population having mild, moderate or severe renal impairment as a whole. Therefore, from these press releases the skilled person cannot directly and unambiguously derive the information that the treatment is effective in each of the subgroups of patients defined by the mentioned levels of renal impairment" (emphasis added).
The Board added that, without specific information regarding the number of patients participating in the trial, the comments in the press release "do not provide any basis for the skilled reader to conclude that as a matter of fact the 25 mg dose must also have been effective in the patients with moderate renal impairment". The skilled person could not directly and unambiguously derive from the reported results that the treatment of patients with "moderate renal impairment" had been successful.
The Board therefore reversed the Opposition Division decision and concluded that the subject-matter of claim 1 of the patent was new over the prior art.
The empagliflozin decision makes it clear that the "purposive selection" criterion is no longer relevant for the assessment of novelty and that the EPC Guidelines on selection inventions also apply to second medical use inventions.
This finding affirmed the decision in case T 1356/21, which concerned a patent that claimed a pharmaceutical composition comprising a defined concentration of insulin glargine for use in the treatment of type 1 and type 2 diabetes mellitus.
The Opponent contended that the specified concentration of insulin in the claims corresponded to a dosage regime, i.e. this feature amounted to a use as opposed to a feature of the product itself, due to the second medical use format of the claim. The Board disagreed.
The Board then considered whether the defined concentration could be considered a novel selection. The Opponent contended that the specified concentration of insulin was an arbitrary selection of a sub-range and, therefore, was not novel, and also that a higher standard of novelty should apply to dosage regimens.
In its decision, the Board stated that the presence of a newly discovered effect in a sub-range singled out of a larger range (i.e. purposive selection) is not a prerequisite for novelty.
Finding that the claim was novel, the Board said the decision of the Enlarged Board of Appeal in case G 2/08 (which confirmed the patentability of new dosage regimes) "did not seek to establish different novelty criteria for numerical ranges in the case of dosage regimen. Thus, the case law in the general situation of numerical ranges, as it has evolved over the years, must apply also in the case of dosage regimen."
It also stated that "the former criterion of a purposive selection (criterion (c)) should no longer be regarded as a requirement under G 2/08 for a dosage regimen to represent a novel selection from a broader range known in the prior art."
Conclusion
The removal of the purposive selection criterion in the 2019 edition of the Guidelines simplified and clarified the law on selection inventions. If there was any doubt about how this would be applied to the novelty of second medical use patents, these two decisions have removed it.
The consequence is that applicants in the life sciences sector can file European patent applications with claims relating to selections from the prior art without having to meet the additional burden of showing purposive selection for novelty. In some cases, this may offer a degree of confidence that such applications will not be rejected on novelty grounds. In general, however, the patentability of second medical use claims will be determined on a case-by-case basis.
For more information on drafting and prosecuting patents for selection inventions, please contact one of Keltie's patent attorneys, who will be happy to advis
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