Medimmune v Novartis - Obviousness

In Medimmune Ltd v Novartis Pharmaceuticals UK Ltd and Another [2011] EWHC 1669 (Pat) (05 July 2011), Mr. Justice Arnold dismissed a claim for infringement of  European Patents (UK) numbers. 0,774,511 and 2,055,777 by selling a product called ranibizumab which is used for the treatment of wet age-related macular degeneration of the eye on the grounds that the patents were invalid for obviousness and that even if the claims relied upon were valid the process used by the defendants to make the product did not infringe.   In Novartis Pharmaceuticals UK Ltd v Medimmune Ltd and Another [2012] EWHC 181 (Pat) (10 Feb 2012) the same judge declared that a supplementary protection certificate granted in respect of European patent number 2,055,777 was invalid not only in the light of his earlier finding but because the certificate was was granted in respect of a product that had not been identified in the wording of the relevant claim as a product deriving from the process in question.

Medimmune appealed against both judgments and Novartis cross-appealed on the ground that the judge should also have found that European patent number 2,055,777 was invalid for insufficiency and that in any case  it would not have been infringed because ranibizumab was not "obtained directly" by means of the claimed process.   Both appeals came on before the Court of Appeal (Lords Justices Moore-Bick, Lewison and Kitchin) in  Medimmune Ltd v Novartis Pharmaceuticals UK Ltd and Others [2012] EWCA Civ 1234 (10 Oct 2012).   At the start of the appeal their lordships requested argument from counsel on obviousness and priority.   Having heard their submissions they indicated that they would uphold the judge's finding on obviousness and that they did not consider it to be in the interests of justice to consider anything else.   The parties agreed and the rest of this note is a discussion of their lordships' decision on whether or not the invention involved an inventive step.

As this is a long and complicated case it is convenient to begin by considering what is meant by "obviousness" and why it is important.   Article 52 (1) of the European Patent Convention ("EPC") provides that European patents shall be granted for any inventions, in all fields of technology, provided that they are new, involve an inventive step and are susceptible of industrial application.  The meaning of "inventive step" is explained in art 56 EPC:

"An invention shall be considered as involving an inventive step if, having regard to the state of the art, it is not obvious to a person skilled in the art......"

The "state of the art" is defined by art 54 (2) EPC as "everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application."   In considering whether an invention was "obvious to a person skilled in the art" Lord Justice Jacob suggested in Pozzoli Spa v BDMO SA and Another [2007] BusLR D117, [2007] EWCA Civ 588, [2007] FSR 37 at paragraph [23] the following four point test:

"(1) (a) Identify the notional "person skilled in the art"
      (b) Identify the relevant common general knowledge of that person;
(2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;
(3) Identify what, if any, differences exist between the matter cited as forming part of the "state of the art" and the inventive concept of the claim or the claim as construed;
(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?"

At trial, Medimmune contended that "the person skilled in the art" or "skilled addressee" would in fact be a team consisting of an immunologist and a molecular biologist, perhaps assisted by a chemist.  Novartis agreed that such the skilled addressee would be a team but argued that it would consist of scientists with differing backgrounds in areas such as immunology, in particular antibody structural biology, molecular biology and protein chemistry, but with a common interest in antibody engineering. Mr. Justice Arnold favoured Novartis's contention on the basis that teams carrying out research in antibody engineering actually consisted of such specialists.  Medimmune criticized the judge's preference on the ground that the invention had a broad application and was not confined to antibody engineering and complained that it had led him into error.   The Court of Appeal had no doubt that Mr. Justice Arnold had been right. Lord Justice Kitchin explained at paragraph [76] that

"As Jacob LJ explained in Schlumberger Holdings Ltd v Electromagnetic Geoservices AS [2010] EWCA Civ 819, [2010] RPC 33 at [42], the court will have regard to the reality of the position at the time and the combined skills of real research teams in the art. A little later, at [53], he continued that where the invention involves the use of more than one skill, if it is obvious to a person skilled in the art of any one of those skills, then the invention is obvious. Finally, at [65], he explained that in the case of obviousness in view of the state of the art, a key question is generally "what problem was the patentee trying to solve?" That leads one in turn to consider the art in which the problem in fact lay. It is the notional team in that art which is the relevant team making up the person skilled in the art."

The next step was to identify the common general knowledge of the skilled addressee as at the priority date.   Lord Justice Kitchin explained at paragraph [78] that:

"[t]he common general knowledge of the notional skilled addressee is all that knowledge which is generally known and generally regarded as a good basis for further action by the bulk of those engaged in a particular art: Beloit Technologies Inc v Valmet Paper Machinery Inc [1997] RPC 489 at 494-495. It also includes all that material in the field in which the skilled addressee is working which he knows exists, which he would refer to as a matter of course if he cannot remember it and which he understands is generally regarded as sufficiently reliable to use as a foundation for further work Raychem Corporation's Patent [1998] RPC 31 at 40; [1999] RPC 497 at 503-504."

As the patent in suit had been granted for a technique of antibody phage display it was common ground that skilled adressees would be familiar with the latest advances in antibody engineering.  The only dispute was whether phage display which was known but had never been used as at the date of the invention was common general knowledge.   The judge had held that it was and the Court of Appeal upheld his finding on the ground that the fact that a technique had not been used did not prevent it from being known.

The inventive concept was set out in claim 1 which Lord Justice Kitchin expressed in integers at paragraph [71]:

"[1] A method for producing a molecule with binding specificity for a particular target, which method comprises:
[2] producing a population of filamentous bacteriophage particles displaying at their surface a population of binding molecules having a range of binding properties,
[3] wherein the binding molecules comprise antibody antigen binding domains for complementary specific binding pair members,
[4] wherein the binding molecules are displayed at the surface of the filamentous bacteriophage particles by fusion with a gene III protein of the filamentous bacteriophage particles,
[5] and wherein each filamentous bacteriophage particle contains nucleic acid encoding the binding molecule expressed from the nucleic acid and displayed by the particle at its surface;
[6] selecting for a filamentous bacteriophage particle displaying a binding molecule with a desired binding property by contacting the population of filamentous bacteriophage particles with a particular target
[7] so that individual binding molecules displayed on filamentous bacteriophage particles with the desired binding property bind to said target;
[8] separating bound filamentous bacteriophage particles from the target;
[9] recovering separated filamentous bacteriophage particles displaying a binding molecule with the desired binding property;
[10] isolating nucleic acid encoding the binding molecule from separated filamentous bacteriophage particles;
[11] inserting nucleic acid encoding the binding molecule, or a fragment or derivative thereof with binding specificity for the target, in a recombinant system; and
[12] producing in the recombinant system separate from filamentous bacteriophage particles a molecule with binding specificity for the target,
[13] wherein the molecule is said binding molecule or a fragment or derivative thereof with binding specificity for the target."

That boiled down to

"(i) producing a population of phage particles displaying at their surface binding molecules having a range of binding specificities wherein each particle contains nucleic acid encoding the binding molecule; (ii) selecting particles displaying a binding molecule with a desired specificity by contacting the population of particles with a target epitope or antigen to which the binding molecule of interest binds."

At trial, Mr. Justice Arnold had considered the contents of a talk entitled "Vectors for the Cloning Immune Response" given by Professor George Smith of the University of Missouri,  one of the leading scientists in the field, to a conference at the Banbury Center of the Cold Harbor Laboratory in New York on 26 April 1990 shortly before the filing date of the patent in suit.  In that talk Professor Smith had set the stage for an experiment that would have performed the invention.   His lordship concluded at paragraph [411] of his judgment that there could be no serious doubt that Professor Smith's talk made it obvious to try phage display of antibodies provided that there was a sufficient expectation of success.  The only question was whether it would have given a skilled addressee a reasonable expectation of success within a reasonable time and after considering the evidence before him the judge decided that it would.   Having formed that view, he had no choice but to find that the invention was obvious.

On appeal, Medimmune contended that the judge had fallen into error on four grounds.   The first was that Professor Smith's paper at the Banbury conference did not go beyond other work that Mr. Justice Arnold had already said did not render the patent invalid for obviousness.  The Court of Appeal rejected that contention on the ground that the science had moved on from the previous work and that in any case Professor Smith's paper did disclose significant differences.   Secondly, Medimmune referred to a grant application by Professor Smith that implied that the work that would have included the experiment he had proposed in his paper would take 5 years and that the prospects of success  of such work were too uncertain to justify giving it to a doctoral student.  The Lords Justices found that Medimmune had taken Professor Smith's words out of context in that he was referring to a much broader project and in any case he later revised his grant application.   Thirdly, Medimmune argued that the fact that Professor Smith thought that the experiment was worth trying did not mean that the skilled addressee would have been of the same opinion.   In focusing on Professor Smith rather than skilled addressees in particular it was said that the trial judge had applied the wrong standard.  The Court of Appeal rejected that submission on the ground that Professor Smith was just as much a skilled addressee as the other scientists working in the field at the time and his opinion on the feasibility of the experiment could not be ignored.   Fourthly, it was submitted that the immunologist in the team would have been deterred from conducting the experiment by concerns over whether antibody fragments would fold, non-specific binding and the fusion phage losing its infectivity.  The Court rejected that argument on the ground that the concerns of one member of the team would not have overridden the curiosity of the others in ascertaining whether Professor Smith's experiment would work.   For all these reasons, their lordships concluded that the trial judge had arrived at the right conclusion.

The difficulties in this case had arisen from the application of the fourth stage of the Pozzoli test, that is to say:

"(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?"

Lord Justice Kitchin addressed the problem between paragraphs [89] and [91] of his judgment:

"[89] It is step (4) which is key and requires the court to consider whether the claimed invention was obvious to the skilled but unimaginative addressee at the priority date. He is equipped with the common general knowledge; he is deemed to have read or listened to the prior disclosure properly and in that sense with interest; he has the prejudices, preferences and attitudes of those in the field; and he has no knowledge of the invention.
[90] One of the matters which it may be appropriate to take into account is whether it was obvious to try a particular route to an improved product or process. There may be no certainty of success but the skilled person might nevertheless assess the prospects of success as being sufficient to warrant a trial. In some circumstances this may be sufficient to render an invention obvious. On the other hand, there are areas of technology such as pharmaceuticals and biotechnology which are heavily dependent on research, and where workers are faced with many possible avenues to explore but have little idea if any one of them will prove fruitful. Nevertheless they do pursue them in the hope that they will find new and useful products. They plainly would not carry out this work if the prospects of success were so low as not to make them worthwhile. But denial of patent protection in all such cases would act as a significant deterrent to research.
[91] For these reasons, the judgments of the courts in England and Wales and of the Boards of Appeal of the EPO often reveal an enquiry by the tribunal into whether it was obvious to pursue a particular approach with a reasonable or fair expectation of success as opposed to a hope to succeed. Whether a route has a reasonable or fair prospect of success will depend upon all the circumstances including an ability rationally to predict a successful outcome, how long the project may take, the extent to which the field is unexplored, the complexity or otherwise of any necessary experiments, whether such experiments can be performed by routine means and whether the skilled person will have to make a series of correct decisions along the way."

He concluded at paragraph [93] that 

"[u]ltimately the court has to evaluate all the relevant circumstances in order to answer a single and relatively simple question of fact: was it obvious to the skilled but unimaginative addressee to make a product or carry out a process falling within the claim."

In his concurring judgment, Lord Justice Lewison agreed.  He referred to dicta of Lord Justice Jacob in Actavis UK Ltd v Novartis AG [2010] EWCA Civ 82, [2010] FSR 18 and Lords Justices Diplock and Wilmer in Johns-Manville Corporation's Patent [1967] RPC 479 that the question of whether or not an invention involves an inventive step is whether the invention is obvious and that any paraphrase or other test is only an aid to answering that question.  He added at paragraph [181] that those sentiments seem to have been largely ignored by the profession and emphasized that the statutory question is: "was the invention obvious at the priority date?" and not: "was it obvious to try?" In his lordship's judgment 

"too much elaboration of the statutory question has been attached to it. The questions of the degree of expectation of success and the length of time thought to be needed to undertake a trial have taken on lives of their own." 

His lordship thought that that has happened in this case.   Having said that, he conceded at paragraph [184] that there are some inventions where the idea of trying an experiment has constituted the inventive step.

Though this case turned very much on its own facts it is likely to be cited frequently as an aid to understanding the Pozzoli test.  Obviousness is often the most promising ground upon which one can defend an infringement action especially since the explosion of prior art in most technologies from North Asia and the advent of the internet which has greatly extended the scope of common general knowledge that can be expected of a skilled addressee.  Although this particular case went against the patentee, the emphasis on the need to return to first principles in the judgments of both Lord Justice Kitchin and Lord Justice Lewison may turn out to be good news for inventors.

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