9.11. Auswahlerfindungen

In T 356/22 the invention sought to provide dosage forms of pomalidomide having advantageous physical and pharmaceutical properties, amongst these being stability. Starting from the pomalidomide composition of claim 22 of closest prior art D1, the differentiating feature was the presence of both mannitol and starch. The decision under appeal was that of the opposition division finding that the patent in suit met the requirements of the EPC.

The respondent (patent proprietor) effectively considered that, since there were no stable dosage forms shown in D1 which could serve as comparator, the achievement of a certain level of stability independently of any comparison with the prior art could be taken into account for the assessment of inventive step. The board did not agree; the circumstances of the case did not justify that the respondent be exonerated from their burden to properly demonstrate that the purported technical effect of the claimed invention had successfully been achieved in comparison with the prior art. That the disclosure of D1 was generic in some respects did not mean that it was speculative or insufficient, nor allowed the assumption that the formulations of D1 suffered from a lack of stability. The mere fact that D1 did not contain any prepared and tested specific formulations of pomalidomide did not change this conclusion; for the purposes of inventive step, the teaching of the prior art is not limited to prepared and tested examples.

The board confirmed that an inventive step could be acknowledged to a selection if this selection was connected to a particular technical effect, and if no hints existed leading the skilled person to the selection. This however supposed that this particular technical effect was convincingly shown for the entire selected subset of formulations by a meaningful comparison with other formulations falling within the ambit of D1.

The respondent cited several decisions to support their view that, when the prior art was unspecific, the achievement of a technical effect per se could be taken into account for the assessment of inventive step. The board firstly noted that in all the cited cases, experimental data were presented in respect of a differentiating feature (citing T 1193/18, T 2342/19, T 2200/17, T 1126/19). But more importantly, the board did not agree that D1 was unspecific; the claimed active ingredient and two excipients were explicitly recited and part of a limited number of emphasised alternatives in D1.

It had to thus be assessed whether the evidence on file convincingly demonstrated that the selection was associated with a technical effect over the pomalidomide formulations of D1, and whether this effect credibly arose over the whole claimed scope. The board did not consider that the application as filed credibly demonstrated the technical effects of improved stability or improved suitability for clinical use for the claimed selected formulations in comparison with D1.

The problem to be solved was thus seen in the provision of an alternative pomalidomide oral dosage form. Since the claimed selection was not shown to be associated with any technical effect, the board found that this selection was arbitrary and did not involve an inventive step. The board noted that considering the problem was only formulated as the provision of an alternative, the lack of preference expressed in D1 for the features selected in present claim 1 did not establish an inventive step, because the chosen alternative was not shown to be any more suitable than the others considered in D1.