Has the 'obvious to try' test been buried?

26 April 2005

Tomos Shillingford

The Court of Appeal recently gave judgment in Saint-Gobain v Fusion Provida and Electrosteel[1], which concerned a patent in respect of an anti-corrosive coating for underground piping. The Court of Appeal’s Judgment could have a significant impact on what constitutes inventiveness.

The Defendants sought to invalidate the patent in suit on the basis that it was ‘obvious to try’ in the light of specified prior art. This area of law has come before the Courts with increasing regularity and has important application to patent protection in a number of industries, particularly the pharmaceutical sector.

Section 3 of the Patents Act 1977 defines inventiveness under UK law (closely following Article 56 of the European Patent Convention):

“An invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art….”.

The way that this is commonly applied in the Courts of England and Wales is by means of the Windsurfing[2] test, which provides:

(1) First the court identifies the inventive concept embodied in the patent in suit.

(2) Next, the court will assume the mantle of the normally skilled but unimaginative addressee in the art at the relevant date and will impute to him what was at that date, common general knowledge in the art in question.

(3) The court should then identify what, if any, differences exist between the matters cited as being “known or used” and the alleged invention.

(4) Finally, the court has to decide whether, viewed without any knowledge of the alleged invention, those differences constitute steps which would have been obvious to the skilled man or whether they required any degree of invention.

In some industries it is necessary to carry out extensive testing of prospective products or methods before it is possible to confirm their benefits. Accordingly, to assess obviousness in the light of a piece of prior art it is sometimes necessary for the Courts to consider to what extent the prior art indicates that the results of the tests will be successful. This has been referred to in the cases as whether or not a particular course would be ‘obvious to try’.

If tests are cheap and easy to carry out then researchers may include variables which have a low chance of success. What likelihood of success in a testing programme does a piece of prior art have to provide? Where is the line drawn?

The most cited Judgment in relation to ‘obvious to try’ is that of the Court of Appeal in Johns Mansville Corporation’s Patent[3]. Diplock LJ noted that the Judge at first instance had used the following expression in his evaluation of obviousness:

“see without difficulty that these newly-introduced polymers would be of advantage in his filtration step”.

He then gave guidance as to the degree of impetus that the prior art must give to the skilled addressee in order for a course of action to have been obvious:

“I think ‘would be’ puts it too high if it postulates prior certainty of success before actually testing the polymers in the filtration process; it is enough that the person versed in the art would assess the likelihood of success as sufficient to warrant actual trial”.

Accordingly, whether something was ‘obvious to try’ has historically been based on whether the skilled man would have had enough expectation of success for it to have been worth carrying out the test. The same test has been applied by the European Patent Office, which has previously sought to evaluate the practical difficulties which might affect an expectation of success[4].

In Saint-Gobain v Fusion Provida and Electrosteel Jacob LJ set out a new formulation of the test:

“None of this to my mind remotely makes the idea of using Zn/Al alloy for pipes obvious – as something which is simply self-evident to the unimaginative man skilled in the art. Mere possible inclusion of something within a research programme on the basis you will find out more and something might turn up is not enough. If it were otherwise there would be few inventions that were patentable. The only research which would be worthwhile (because of the prospect of protection) would be into areas devoid of prospect. The “obvious to try” test really only works where it is more-or-less self-evident that what is being tested ought to work”.

Jacob LJ appears to have lowered the bar for inventiveness where testing is required. It must now be “more-or-less self evident that what is being tested ought to work” before an ‘invention’ is considered to be obvious. This seems to be at variance with the previous understanding of the law, which rendered a line of research obvious if there was sufficient expectation of success for the tests to have been carried out. This would appear to be encouraging news for patentees in England and Wales, a jurisdiction which is commonly viewed as being anti-patentee. Indeed this shift may constitute a reaction against that reputation.

If this new attitude proves enduring there may be a significant impact on the activities of Biotech and Pharmaceutical research organisations. If the same reasoning is to be applied in these industries then many more avenues of research will be protectable. It may be possible to argue that a contra-indication of any substance leads to the success of research not being “self-evident”, rendering it patentable.

What happens where the circumstances are such that you could not carry out any test with any reasonable expectation of success? On a literal interpretation of this new test, nothing would be obvious as it would not be self-evident that the relevant research would work. It will be interesting to see if the new test will develop in this regard.

Before authors rush to amend textbooks and practitioners apply to amend their pleadings it is worth pointing out Lord Diplock’s caveat in Johns Mansville Corporation’s Patent:

“The correctness of a decision upon an issue of obviousness does not depend upon whether or not the decider has paraphrased the words of the Act in some particular verbal formula”.

As noted by Aldous LJ in Norton Healthcare v Beecham Group[5], obviousness is a statutory test, and there is no formula which can be substituted for the words of the statute. However, it is difficult to apply the words of the statute to ‘obvious to try’ cases and judicial guidance is desirable. The test set out in Johns Mansville Corporation’s Patent had provided that guidance. It remains to be seen whether the Judgment of the Court of Appeal in Saint-Gobain v Fusion Provida and Electrosteel was made on the particular facts of that case or whether the new formulation of Jacob LJ will be applied in the future. For the moment, at least, the Johns Mansville test is dead, buried and possibly corroding.

First published inthe April 2005 edition of WIPR.







[1] [2005] EWCA (Civ) 177, LTL 25/2/2005



[2] Windsurfing International Inc. v Tabur Marine (Great Britain) Ltd [1985] R.P.C. 59 at 73-74



[3] [1967] R.P.C. 479 at 493



[4] Biogen, Inc. / Human-Beta Interferon OJEPO 1999, 273 (T0207/94)



[5] CHOCF 95/1554/B – 19/6/1997