Wednesday, 24 November 2010

T 12/07 – Where Could/Would Ends

When assessing inventive step within the framework of the problem-solution approach, the EPO often invokes the so-called “could/would” approach, following T 2/83 [7], where it was stated that “[t]he question regarding the inventive step, in relation to the modification of the layered tablet of the state of the art as suggested by the present applicants, is not whether the skilled man could have inserted a barrier between the layers but whether he would have done so in expectation of some improvement or advantage”, and T 143/86 [5] where we read: “It is perhaps worth while pointing out in this respect that, in order to avoid an ex post facto analysis, the test to be applied when considering the question of whether the combination of the teachings of two prior art documents involves an inventive step is whether the man skilled in the art would have combined them, and not whether he could have combined them.”

The present decision shows that there are cases where the should/would approach is not to be applied.

[4.1.1] The present invention relates to methods of preventing or reducing aggregate formation of growth hormones, growth factors, insulin, monoclonal antibodies and interferons upon dehydration and rehydration […].

[4.1.2] Document D15 relates to the stability of proteins during freeze-drying […]. For deciding whether document D15 qualifies as the closest prior art, it is important to evaluate whether or not stability in the context of document D15 includes prevention or reduction of aggregate formation. In the light of the disclosure [of D15], the board is convinced that this is the case.

The relevant passage reads as follows:
“Manufacturers can minimize the degradation that arises from aggregation and other mechanisms by paying careful attention to the details of the freeze-drying process. Most often, however, stability problems are addressed by varying the formulation. For example, excipients, or lyoprotectants, are added to improve stability of the dried product.”
The board concludes from this passage that lyoprotectants are used for improving stability and that prevention or reduction of aggregation is one aspect of stability according to document D15.

Further evidence that resistance to aggregate formation is comprised in the term stability is provided by the specific examples […] (“The stability (resistance to aggregate formation)of …”)). It is not denied that loss of protein activity and denaturation are not necessarily linked to aggregation, as was pointed out by the appellant-patentee. However, this fact is of no relevance, as document D15 contains the teaching that the lyoprotectants disclosed therein, which include trehalose as one of the preferred lyoprotectants […], are inter alia used for protecting the proteins against aggregation.

[4.1.3] As a consequence, document D15 constitutes the closest prior art and the problem to be solved can be defined as the provision of a further method of preventing aggregation during lyophilisation and rehydration of proteins.

This problem was solved by the method as claimed in claim 1 of the main request, i.e. by choosing trehalose as protective agent for growth hormones, growth factors, insulin, monoclonal antibodies or interferon. In the light of the data in Tables 1 and 2, the board is satisfied that the problem defined above was plausibly solved.

[4.1.4] In view of the teaching that the lyoprotectants according to document D15 […] are all suitable to suppress or reduce aggregate formation during freeze-drying and storing of proteins in general, the specific combination of trehalose with one of the proteins according to present claim 1 is nothing but an arbitrary selection, which in the absence of any non-obvious effect does not involve an inventive step. The skilled person concludes from the teaching of document D15 that the problem defined [above] could be solved no matter whether trehalose or any of the other lyoprotectants according to document D15 was chosen. Such an arbitrary selection cannot give rise to an inventive step.

[4.1.5] The appellant-patentee held that the proteins defined in present claim 1 were used parenterally [NB: According to Wikipedia, parenteral is a route of administration that involves piercing the skin or mucous membrane; parenteral nutrition refers to providing nutrition via the veins.] and in multiple doses. Although not specifically mentioned in the claims, this feature was implicitly disclosed by the selection of the proteins. As a consequence, the skilled person would not select trehalose, sucrose, human serum albumin or bovine serum albumin, which had the drawback of not having an established history in the formulation of pharmaceutical products for parenteral therapy […].

Not having an established history in the formulation of pharmaceutical products for parenteral therapy does not mean, however, that these lyoprotectants are not suitable. It simply means that this suitability must possibly be verified by standard tests, which do not require inventive skill and which do not keep the skilled person from taking these lyoprotectants into consideration. On the contrary: as trehalose and the three further lyoprotectants mentioned above are commonly used as lyoprotectants […], they are preferred by the skilled person, as their stabilising effect and, as a consequence, their aggregate-reducing effect is beyond any doubt. This argument can therefore not succeed, even it is assumed in favour of the appellant-patentee that the parenteral application in multiple doses is an implicit feature of claim 1.

[4.1.6] The appellant-patentee further argued that the skilled person, starting from the teaching of document D15, had no reasonable expectation of success by selecting trehalose in combination with the specific proteins as defined in claim 1, in view of the numerous options that were at his disposal. He could but would not have made this selection.

As was mentioned above […] the skilled person made an arbitrary selection from the teaching of document D15 in order to arrive at the claimed invention. The method according to present claim 1 is just one of many possibilities for solving the problem defined […] above. As a consequence, the “could/would-approach” does not apply in the present case.

[4.1.7] As a consequence, the subject-matter of claim 1 and of dependent claims 2 to 4 does not meet the requirements of A 56.

Should you wish to read the whole decision, just click here.


Anonymous said...

This decision reminds me of the discussion in the comments here.

pat-agoni-a said...

I just browsed through the comments mentione above. They are interesting and amusing at the same time. I believe that an underlying assumption in the debate is that there must be a method for judging inventiveness that always leads us to the right answer. Although it is very desirable that a judgement be previsible, judging matters of degree is not natural science. The result quite often depends on the approach taken and often also on non-spoken implicit assumptions.
The problem-solution approach tries to reduce the gap in the question "would the skilled person have done this?", but it is not a mathematical tool that gives a single answer for every possible situation.

So what is left is to apply common sense, but alas this is not the same thing for everybody.

Anonymous said...

Well, PSA *is* the method that the Boards and first instances apply, so it is certainly worthwhile to discuss the "technicalities" of this approach. One such "technicality" is how to deal with a distinguishing feature not achieving a technical effect. Is it enough that the skilled person "could" adapt the closest prior art to exhibit the feature, or is something more necessary (e.g. some kind of hint in the prior art) to show that the skilled person "would"?

I believe this is not simply a question that has different answers depending on the facts of the case, but truly a legal question.

I also believe that the answer can be found by applying common sense. Using the posterior of a child as a paint tool is not inventive but only silly (common sense). This is independent of whether any hint can be found in the prior art for this use of a child's posterior (common sense). Therefore the existence of such a hint should not be a requirement for finding a lack of inventive step (logical deduction). Therefore the fact that a child's posterior used as a paint tool does not provide any technical effect over the use of known paint tools should be sufficient for finding a lack of inventive step, i.e. in the absence of a technical effect it is sufficient that the skilled person "could".

(Note that I'm not saying that the silliness factor takes away inventive step. It's the lack of a technical effect that does that. The silliness only makes visible, from a common sense point of view, that a hint in the prior art cannot be a requirement. Indeed, the more silly, the less likely that there is relevant prior art.)