Key points
- Claim 1 is directed to a polymorph. "It is common ground that compound (1) as prepared in example 6 of D3 is in amorphous form (see also example 5 of the patent, reproducing example 6 of D3). Therefore, the feature distinguishing the subject-matter of claim 1 as granted from example 6 of D3 is that compound (1) is in the crystalline form I."
- "The board [...] considers that the objective technical problem should at least be seen as the provision of a more stable and non-hygroscopic form of compound (1). "
- "as pointed out by the respondent [proprietor], example 1 of the patent (page 19) shows the crystallisation procedure used to achieve form I of compound (1). Among a high number of single solvents and solvent combinations used (75 in total, see table 1 on pages 20 to 25), only four mixtures of solvents (samples 23, 24, 39 and 58) led to form I. In the other cases, when solids were obtained, these represented the amorphous form or, in two instances (samples 53 and 69), a different polymorphic form of compound (1) named form II. Anti-solvent experiments did not lead to form I of compound (1) either "
- "Additionally, while it can be accepted that it would have been expected by the skilled person that crystalline forms are more stable than amorphous forms, the results of the patent (see summary provided by the respondent on page 13 of the reply to the statement of grounds of appeal) show that two further polymorphic forms (form II and form III) of compound (1) were found to be more hygroscopic than form I."
- Including the non-working non-claimed examples and alternative polymorphs in the patent application seems a smart move in this case.
- See also: Dai Rees, Inventive Step: The Stories We Tell - link
- "as set out above, form I has a lower hygroscopicity than forms II and III. Thus, in contrast to the condition referred to under point 5.2 of the reasons of decision T 777/08 for denying inventive step, form I, in terms of its hygroscopicity, is not an arbitrary selection of a specific polymorph from a group of equally suitable candidates."
- The Board did not A14, an experimental report drawn up in 2022, i.e. seven years after the priority date, which was filed by the appellants with the statement of grounds.
- According to the opponent/appellant: "A14 demonstrated that if the skilled person had tried standard crystallisation solvents as disclosed e.g. in D7 [prior art, c.g.k.], they would necessarily have arrived at form I of compound (1) as defined in granted claim 1. A14 also showed that no other solid form was crystallised."
- The Board: "the filing of A14 raises complex issues. In fact, admitting A14 would require, for example, considering whether a characterisation by X-ray powder diffraction of the starting sample used in A14 unambiguously allows concluding that the starting material was in amorphous state and that no crystalline material was present. This was contested by the respondent. It would also require assessing whether the crystallisation procedure followed in A14 was such to unambiguously exclude the presence of unintentional seeding. The discussion and consideration of these complex issues would have been detrimental to procedural economy and contrary to the primary object of the appeal proceedings to review the appealed decision in a judicial manner (Article 12(2) RPBA)."
EPO
The link to the decision can be found after the jump.