Judgments - Conor Medsystems Incorporated (Respondents) v Angiotech Pharmaceuticals Incorporated and others (Appellants)

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27.  For the reasons I have given, I am afraid that I cannot agree with this analysis. In my opinion it is absolutely clear that the teaching of the specification, so far as it supported claim 12, was that a taxol-coated stent would prevent or treat restenosis. I agree with the opinion of the Dutch court (at paragraph 4.17):

“…[T]he patentee sufficiently clearly indicates in the patent that it is advantageous to use taxol (inter alia but also specifically for restenosis) and states as reason for this that taxol…scores well in the CAM assay to demonstrate its anti-angiogenic effect, bearing in mind that the patentee saw the solution for restenosis in the use of an anti-angiogenic factor.”

28.  The question was whether that was obvious and not whether it was obvious that taxol (among many other products) might have this effect. It is hard to see how the notion that something is worth trying or might have some effect can be described as an invention in respect of which anyone would be entitled to a monopoly. It is therefore perhaps not surprising that the test for obviousness which Pumfrey J devised for such an “invention” was whether it was obvious to try it without any expectation of success. This oxymoronic concept has, so far as I know, no precedent in the law of patents.

29.  It is true that a patent will not be granted for an idea which is mere speculation, unsupported by anything disclosed in the specification. Article 84 of the EPC says that the claims must be “supported by the description” and this requirement is reproduced in section 14(5)(c) of the 1977 Act. So in Re Prendergast’s Applications [2000] RPC 446, the applicant attempted to patent the use of two known pharmaceuticals to treat —

“battle fatigue, combat stress reaction, post-traumatic stress disorder in civilian and military emergency situations, neurological symptoms associated with chemical warfare and nausea associated with chemical or biological warfare.”

30.  The specification contained no information whatever to support the claim that the products in question would have any effect on these ailments. Neuberger J upheld the Comptroller’s rejection of the claim on the ground that it was not supported by the description.

31.  In this case, however, the patent had been granted by the EPO and article 84 was therefore no longer in issue. There is also a line of authority in the EPO in which claims to broad classes of chemical compounds alleged to have some common technical effect have been rejected under article 56 (obviousness) when there was nothing to show that they would all have that technical effect. The leading case is AGREVO, Case No T 0939/92, which was a product claim for a class of chemical compounds alleged to be useful as herbicides. But there was nothing in the description to justify the assertion that all the compounds in the class would have herbicidal properties. The Board of Appeal decided that the claims were not insufficient (the skilled man would have been able to make all the compounds claimed) but failed for lack of an inventive step because there was nothing inventive in simply making the compounds. The invention, if any, would lie in the discovery that they were herbicides. The Board of Appeal said (at paragraph 2.5.4):

“…[A] technical effect which justifies the selection of the claimed compounds must be one which can be fairly assumed to be produced by substantially all the selected compounds...”

32.  At paragraph 2.6.2 the Board acknowledged that a patentee does not have to have tested every compound to see whether it has the claimed effect: “reasonable predictions of relations between chemical structure and biological activity are in principle possible, but that there is a limit beyond which no such prediction can be validly made.”

33.  The case of Johns Hopkins University School of Medicine Case No T 1329/04 deals with the question of whether the use which may be made of the claimed product (ie that which may constitute the inventive step) must be stated in the specification or can be proved by later evidence. The claim was to a DNA sequence encoding a protein “having GDF-9 activity". Again, as in AGREVO, there was nothing inventive in simply making the DNA sequence. The inventive step, if any, would lie in a disclosure that it coded for a useful protein . But the specification disclosed no more than speculation about how GDF-9 activity might be useful. The examining division rejected the application on the ground that such speculation did not go beyond what was obvious and refused to take into account subsequently published material showing specific properties of GDF-9.

34.  The Board of Appeal pointed out (at paragraph 10) that in the specification various effects were “tentatively and presumptively” attributed to GDF-9. It went on:

“[T]he issue here is…how much weight can be given to speculations in the application in the framework of assessing inventive step, which assessment requires that facts be established before starting the relevant reasoning. In the board’s judgment, enumerating any and all putative functions of a given compound is not the same as providing technical evidence as regard a specific one…[T]here is not enough evidence in the application to make at least plausible that a solution was found to the problem which was purportedly solved.”

35.  The Board then went on to consider whether this deficiency could be remedied by evidence coming into existence after the application:

“12.  The appellant filed post-published evidence… establishing that GDF-9 was indeed a growth differentiation factor. This cannot be regarded as supportive of an evidence which would have been given in the application as filed since there was not any. The said post-published documents are indeed the first disclosures going beyond speculation. For this reason, the post-published evidence may not be considered at all. Indeed, to do otherwise would imply that the recognition of a claimed subject-matter as a solution to a particular problem could vary as time went by. Here, for example, had the issue been examined before the publication date of the earliest relevant post-published document, GDF-9 would not have been seen as a plausible solution to the problem…and inventive step would have had to be denied whereas, when examined thereafter, GDF-9 would have to be acknowledged as one such member. This approach would be in contradiction with the principle that inventive step, as all other criteria for patentability, must be ascertained as from the effective date of the patent. The definition of an invention as being a contribution to the art, i.e. as solving a technical problem and not merely putting forward one, requires that it is at least made plausible by the disclosure in the application that its teaching solves indeed the problem it purports to solve. Therefore, even if supplementary post-published evidence may in the proper circumstances also be taken into consideration, it may not serve as the sole basis to establish that the application solves indeed the problem it purports to solve.”

36.  These cases are in my opinion far from the facts of this case. The specification did claim that a taxol coated stent would prevent restenosis and Conor did not suggest that this claim was not plausible. That would have been inconsistent with the evidence of its experts that taxol was just the thing to try. It is therefore not surprising that implausibility was neither pleaded nor argued. The same was true of the proceedings in the Netherlands (see paragraph 4.17 of the judgment).

37.  The Court of Appeal upheld the judgment of Pumfrey J on the ground that the patent contained no “disclosure” saying that taxol was specially suitable for preventing restenosis. Again, I agree that the description, though offering a theory (its anti-angiogenic properties) as to why taxol would prevent restenosis, did not offer any evidence that this would turn out to be true. If it had not turned out to be true, the patent would have been insufficient. But there is in my opinion no reason as a matter of principle why, if a specification passes the threshold test of disclosing enough to make the invention plausible, the question of obviousness should be subject to a different test according to the amount of evidence which the patentee presents to justify a conclusion that his patent will work.

38.  The issue in the Court of Appeal appears to have been whether the teaching of the patent was that a taxol-coated stent would prevent or treat restenosis. Jacob LJ disagreed with the view of the Dutch court, which I have already quoted, that that was precisely what the patent said. He said that the Dutch court had formed its view “with the hindsight knowledge that taxol stents work". I do not think that this is a fair criticism. The Dutch court was not addressing itself to whether taxol worked, or whether the specification proved that it would work, but to whether the specification taught that it should be used. And it did so by reference to the disclosure of the success of taxol in the CAM assay and the specific references to taxol in the claims. Jacob LJ considered that there was nothing in these points. After reading part of the passage about the CAM assay which I have quoted above, he said:

“But this is miles away from indicating that taxol is a particularly suitable anti-angiogenic for a drug eluting vascular stent or that the CAM assay is a test for a drug which will actually work to prevent restenosis in a drug eluting vascular stent.”

39.  If, by using the word “indicating", Jacob LJ meant “proving", then of course I agree. The specification did not prove that taxol would work. If, however, he meant that it did not claim that taxol would work, then I would regard it as a very narrow approach to the meaning of the patent, more suitable to old-fashioned statutory construction than to what the skilled practitioner in cardio-vascular intervention would have understood. It was, as appears from Mr Thorley’s question to Professor Cumberland, common ground that that the teaching of the patent was to use an anti-angiogenic factor on a stent to prevent or treat restenosis. The disclosure of the results of the CAM assay taught that taxol was the best anti-angiogenic. I do not understand what more the patentee could have said.

40.  In the event, therefore, neither the judge nor the Court of Appeal answered what I consider to have been the correct question, namely, whether it was obvious to use a taxol-coated stent to prevent restenosis. One can however, deduce the answer which Pumfrey J would have given to this question from the way in which he formulated the issue which he had to decide. It was, at the end of the passage I have quoted:

“is the patent vulnerable only if it can be shown that the skilled person would have an expectation of success sufficient to induce him to incorporate taxol in a drug-eluting stent, or is it sufficient that without any expectation of success he would test or screen taxol?”

41.  The judge answered this question in the second sense, from which I think it can be inferred that he would have rejected the attack on the patent if he had answered it in the first and in my opinion correct sense. That, in my view would have been inevitable. Of the three cited items of prior art, both Wolff and Kopia are concerned with methods of delivery. In the case of Wolff, it is by a drug eluting stent and in the case of Kopia it is by chemical means. But neither of them identifies taxol as particularly suitable. Wolff does not mention it except by implication in a generic reference to anti-proliferatives and although Kopia does mention it, it is one of an undifferentiated number of drugs which could be tried. The disclosures leave one in no better position than a reader of the Holy Grail article, namely, with the knowledge that the solution may lie somewhere in the large number of drugs which could be tried. Katsuda, the last item of prior art, discloses in vitro work which showed that taxol prevented mitogenic proliferation (ie growth by cell division) of smooth muscle cells. That also seems to me insufficient to make it obvious that taxol would prevent restenosis.

42.  In the Court of Appeal, Jacob LJ dealt comprehensively with the question of when an invention could be considered obvious on the ground that it was obvious to try. He correctly summarised the authorities, starting with the judgment of Diplock LJ in Johns-Manville Corporation’s Patent [1967] RPC 479, by saying that the notion of something being obvious to try was useful only in a case in which there was a fair expectation of success. How much of an expectation would be needed depended upon the particular facts of the case. As Kitchin J said in Generics (UK) Ltd v H Lundbeck A/S [2007] RPC 32, para 72:

“The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success.”

43.  But Jacob LJ rejected this approach (at paragraph 48) on the grounds that “this is not an ‘obvious to try’ case of the Johns-Manville type” because “the patent has not in any way demonstrated that taxol actually works to prevent restenosis.” I agree with the Dutch court that patent law does not require such a demonstration. It was not a sufficient reason for not applying the ordinary principles of obviousness to the claimed invention. I would therefore allow the appeal.


My Lords,

44.  I have had the advantage of reading a draft of the opinion of my noble and learned friend Lord Hoffmann. I am in agreement with it and for the reasons he gives I too would allow the appeal.


My Lords,

45.  I have had the privilege of reading in draft the opinion of my noble and learned friend Lord Hoffmann. I am in full agreement with his opinion, and for the reasons that he gives I would allow this appeal. I am doubtful whether I can usefully add anything. But I venture to add a few remarks on the notion of “obvious to try,” and its relevance to this appeal.

46.  Its origin was in the judgment of Diplock LJ in Johns-Manville Corporation’s Patent [1967] RPC 479, a case about a method for production of asbestos cement. After referring to two items of prior art Diplock LJ said at p 495:

“It is enough that the person versed in the art would assess the likelihood of success as sufficient to warrant actual trial. . . . The Superintending Examiner and the Patents Appeal Tribunal were both of opinion that, filtration processes being common to many industries, these documents, although addressed primarily to the mining and paper industries respectively, were likely to be read by those concerned with the asbestos cement industry, and that such readers would have realised that here was a newly-introduced flocculating agent which it was well worth trying out in their own filtration process. I can see no grounds which would justify this court in reversing this concurrent finding by two expert tribunals.”

Diplock LJ was not here expounding a technical doctrine. On the contrary, he was at pains to stress the need to avoid generalisation. A little earlier in his judgment he had said (at pp 494-495):

“I have endeavoured to refrain from coining a definition of ‘obviousness’ which counsel may be tempted to cite in subsequent cases relating to different types of claims. Patent law can too easily be bedevilled by linguistics, and the citation of a plethora of cases about other inventions of different kinds. 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. I doubt whether there is any verbal formula which is appropriate to all classes of claims.”

47.  Johns-Manville was decided over forty years ago, and was concerned with a fairly low-tech process. During the last forty years the volume of high-tech research has increased enormously, especially in the fields of pharmaceuticals and biotechnology. The resources committed to research are enormous, because the potential rewards in world-wide markets are so great. Competition is fierce. In this climate “obvious to try” has tended to take on a life of its own as an important weapon in the armoury of those challenging the validity of a patent.

48.  The process has been vividly described in observations made out of court by Sir Hugh Laddie, Patents - what’s invention got to do with it? (Chapter 6 in Intellectual Property in the New Millenium, p.93):

“When patents and patent applications succumb to invalidity attacks, obviousness is the most common cause. This inevitably generates friction between the community of patentees and applicants on the one hand and patent offices and national courts on the other. A company which has spent millions of dollars on research and has produced a valuable new drug will be understandably irritated when, say, a court declares the patent invalid for obviousness, thereby opening up the market to competitors who are free to copy. That irritation is likely to be particularly acute when the raison d'être of the patent system is said to be the economic encouragement of research and development.

The problems can be approached by considering first the concept of ‘obvious to try'. The classic statement of this principle is set out in the judgment of the Court of Appeal in Johns-Manville Corporation’s Patent. It was said that a development should be treated as obvious if ‘the person versed in the art would assess the likelihood of success as sufficient to warrant actual trial'. Statements to similar effect have been made by the EPO.

On its face, this produces an unworkable or irrational test. If the reward for finding a solution to a problem and securing a monopoly for that solution is very high, then it may well be worthwhile for large players to examine all potential avenues to see if one gives the right result, even though the prospects of any one of them succeeding are much less than 50/50. What makes something worth trying is the outcome of a simple risk to reward calculation. Yet, if the reward is very large, the avenues worth trying will be expanded accordingly. So, the more commercially attractive the solution and the more pressing the public clamour for it, the harder it will be to avoid an obviousness attack. In those circumstances a solution which is quite low down a list of alternatives, all of which are more or less worth trying, will fail for obviousness; a consequence which is consistent with the decision in Brugger v Medic-Aid.”

Sir Hugh goes on to suggest that as technology advances rapidly, this is a serious and growing problem.

49.  In the Court of Appeal in this case Jacob LJ (paras 39-45) made some comments to the same general effect, with a useful anthology of citations from different jurisdictions.

50.  This background helps to explain the question which the judge asked himself (at the end of para 61 of his judgment), including the reference to testing a product “without any expectation of success” (which Lord Hoffmann refers to as an “oxymoronic concept”). The judge sought to answer the question (para 62) by assessing the contribution to the art made by the specification, and decided (para 64) that the only real contribution was a proposal for testing (and no more). In this way arguments that would normally be regarded as relevant to insufficiency crept into a challenge on the ground of obviousness.

51.  Your Lordships all concur, as I do, in Lord Hoffmann’s view that the judge and the Court of Appeal took too narrow a view of the specification of the patent in suit, probably because they attached insufficient weight to the CAM assay. What that assay demonstrated fell far short of what might have been demonstrated (and was in due course demonstrated) by clinical trials in treating restenosis after angioplasty. The CAM assay was not a last-minute last-ditch point taken in reply in the Court of Appeal. It had not been much discussed in the judge’s judgment because it was not then regarded as a contentious issue.

52.  So the patent has finally been upheld in your Lordships’ House. I have to say that in my view the inventors and those who drafted the specification have to some extent brought the tribulations of this litigation on themselves. As the judge said (para 12):

“The patent is a very long document, containing some 37 pages of description and 34 pages of figures. Very little of it is about restenosis and stents.”

That is putting it quite mildly. The inventors were carrying on research work with various substances which held out the prospect of exciting medical advances, not only in preventing restenosis but also in the treatment of cancer. They understandably wished to cover as much ground as possible in the specification. But in doing so they risked making it so unfocused as to end up with nothing capable of resisting a challenge to its validity.

53.  The European Patent Office focuses on the need for an invention to solve a particular technical problem: see for instance AGREVO, Case-T0939/92, paras 2.4 to 2.4.2. So far as the focus was on stents, there was a particular technical problem, clearly highlighted in the “Holy Grail” paper published in 1993. The specification, fairly construed, did put forward a taxol-eluting stent as the answer to this problem. But that teaching had to be disentangled from so much extraneous matter that it nearly got lost.


My Lords,

54.  For the reasons given by my noble and learned friend, Lord Hoffmann, with which I agree, I too would allow this appeal.


My Lords,

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