In  Gedeon Richter plc v Bayer Schering Pharma AG [2011]  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.