Gedeon Richter plc v Bayer Schering Pharma AG: “Obvious to Try” and “Fair Expectation of Success”
In Gedeon Richter plc v Bayer Schering Pharma AG  EWHC 583 (Pat), Gedeon Richter plc applied to have two divisional patents belonging to Bayer Schering Pharma AG revoked for invalidity (the ‘301 and ‘069 patents). One of the grounds of invalidity was that the patents were obvious in respect of four items of prior art.
The patents were for the combination of two steroidal hormones, ethinylestradiol (EE) and drospirenone (DSP), both of which regulate the female menstrual cycle and are used as a contraceptive. Both patents under examination were aimed at finding an effective and safe formulation of the hormones in the development of an oral contraceptive pill. They were directed towards a skilled formulation team working specifically in the area of the development of oral contraceptives.
Both sides in this case were agreed that there was nothing inventive per se in embarking on in vitro pre-formulation testing to determine the physico-chemical characteristics of the ingredients concerned. Such tests would be performed in ignorance of the results of the testing and in ignorance of whether any particular formulation strategy would have a fair expectation of success. But they would nevertheless be an obvious thing to do. They were said to be obvious because the evidence showed that the skilled person would do them anyway, as part of his routine work. The question was, however, how would the skilled person proceed after having undertaken such obvious tests? This question would, Floyd J said, involve more in the way of a value judgment. Further, he said, the mere fact that such further steps could be characterised as being performed in order to make an informed decision did not prevent those steps necessarily from contributing to a finding of inventiveness.
Floyd J summarised the case law on obviousness and looked also at the “obvious to try” test.
“Where, therefore, the evidence reveals that to arrive at the invention, the skilled person has to embark on an experiment or series of experiments where there was no fair expectation of success, the conclusion will generally be that the invention was not obvious. Mr Thorley submitted that one had to distinguish between experiments which were conducted in order to make an informed decision as to what to do, and experiments which are conducted only because it is believed that they will produce the desired end result. The former type could be obvious experiments to do, notwithstanding that they were performed without any prior knowledge of the result, or whether the result would predict a successful outcome of the whole project. There was an independent motive for driving the project forward, namely to find out whether a solution to the problem was possible.”
Further, in Floyd J’s view, there was no general rule: the guiding principle must be that one has to look at each putative step that the skilled person is required to take and decide whether it is obvious. Even then, he said, one has to step back and ask an overall question as to whether the step by step analysis, performed after the event, may not in fact prove to be unrealistic or driven by hindsight.
The expert witnesses differed in their analysis of what steps the skilled person would take after having undertaken the in vitro tests to determine the rate of dissolution in an acidic environment. The expert witness for the Defendant said that he would take the results of dissolution to mean that an enteric coat (a layer added to oral medications to allow the active ingredient to pass through the stomach and be absorbed in the intestine) needed to be adopted and that he would not take an immediate release formulation (i.e., an uncoated ingredient) into animal trials. The expert witness for the Claimant said, however, that he thought it would be prudent to proceed to an animal model to assess the relative merits of both an uncoated and a coated formulation.
Floyd J was not able to conclude that it would be routine to do animal tests on an uncoated formulation. It would, he said, be a matter for the skilled judgment of the formulator. Therefore, it was not, in Floyd J’s view, obvious on the basis of the information acquired by in vitro testing. Further, it would not be a step that the skilled person would be able to take with the necessary “fair expectation of success”. The skilled formulator 2 would have well in mind, he said, that success in this field included near certainty of efficacy in all patients. The difficulties likely to be encountered if the drug were allowed to pass unprotected into and through the stomach would not, therefore, be productive of confidence.
However, while claim 1 of the ‘301 patent and claim 6 of the ‘069 patents were not found to be obvious, Floyd J found that the two claims that set out the steps taken to improve the rate of dissolution by surface coating inert particles with DSP or by spraying were obvious. Floyd J found that it would be obvious to a skilled person to surface coat inert particles in order to achieve a better dissolution rate. As for spraying, this was found to be part of the common general knowledge for achieving rapid dissolution of a poorly soluble ingredient. Therefore, these claims were both found to lack inventive step.