Judgments - Synthon BV (Appellants) v. Smithkline Beecham plc (Respondents)

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    22.  If I may summarise the effect of these two well-known statements, the matter relied upon as prior art must disclose subject-matter which, if performed, would necessarily result in an infringement of the patent. That may be because the prior art discloses the same invention. In that case there will be no question that performance of the earlier invention would infringe and usually it will be apparent to someone who is aware of both the prior art and the patent that it will do so. But patent infringement does not require that one should be aware that one is infringing: "whether or not a person is working [an] ... invention is an objective fact independent of what he knows or thinks about what he is doing": Merrell Dow Pharmaceuticals Inc v H N Norton & Co Ltd [1996] RPC 76, 90. It follows that, whether or not it would be apparent to anyone at the time, whenever subject-matter described in the prior disclosure is capable of being performed and is such that, if performed, it must result in the patent being infringed, the disclosure condition is satisfied. The flag has been planted, even though the author or maker of the prior art was not aware that he was doing so.

    23.  Thus, in Merrell Dow, the ingestion of terfenadine by hay-fever sufferers, which was the subject of prior disclosure, necessarily entailed the making of the patented acid metabolite in their livers. It was therefore an anticipation of the acid metabolite, even though no one was aware that it was being made or even that it existed. But the infringement must be not merely a possible or even likely consequence of performing the invention disclosed by the prior disclosure. It must be necessarily entailed. If there is more than one possible consequence, one cannot say that performing the disclosed invention will infringe. The flag has not been planted on the patented invention, although a person performing the invention disclosed by the prior art may carry it there by accident or (if he is aware of the patented invention) by design. Indeed, it may be obvious to do so. But the prior disclosure must be construed as it would have been understood by the skilled person at the date of the disclosure and not in the light of the subsequent patent. As the Technical Board of Appeal said in T/396/89 UNION CARBIDE/high tear strength polymers [1992] EPOR 312 at para 4.4:

    "It may be easy, given a knowledge of a later invention, to select from the general teachings of a prior art document certain conditions, and apply them to an example in that document, so as to produce an end result having all the features of the later claim. However, success in so doing does not prove that the result was inevitable. All that it demonstrates is that, given knowledge of the later invention, the earlier teaching is capable of being adapted to give the same result. Such an adaptation cannot be used to attack the novelty of a later patent."

    24.  Although it is sometimes said that there are two forms of anticipatory disclosure: a disclosure of the patented invention itself and a disclosure of an invention which, if performed, would necessarily infringe the patented invention (see, for example, Laddie J in Inhale Therapeutic Systems Inc v Quadrant Healthcare Plc [2002] RPC 21 at para 43) they are both aspects of a single principle, namely that anticipation requires prior disclosure of subject-matter which, when performed, must necessarily infringe the patented invention.

    25.  As I have indicated by reference to the quotation from UNION CARBIDE, it is this requirement that performance of an invention disclosed in the prior art must necessarily infringe the patent which distinguishes novelty from obviousness. If performance of an invention disclosed by the prior art would not infringe the patent but the prior art would make it obvious to a skilled person how he might make adaptations which resulted in an infringing invention, then the patent may be invalid for lack of an inventive step but not for lack of novelty. In the present case, the Synthon application is deemed to form part of the state of the art for the purposes of novelty (section 2(3)) but not for the purpose of obviousness (section 3). As Synthon rely solely upon section 2(3) matter as prior art, they do not rely and cannot succeed on obviousness.

    (b)  Enablement

    26.  Enablement means that the ordinary skilled person would have been able to perform the invention which satisfies the requirement of disclosure. This requirement applies whether the disclosure is in matter which forms part of the state of the art by virtue of section 2(2) or, as in this case, section 2(3). The latter point was settled by the decision of this House in Asahi Kasei Kogyo KK's Application [1991] RPC 485.

    27.  Asahi's case was decided on the assumed facts that there had been a prior disclosure of the same invention (a particular polypeptide) but that neither the disclosed information nor common general knowledge would have enabled the skilled man to make it. The House therefore did not have to consider the test for deciding what degree of knowledge, skill and perseverance the skilled man was assumed to have. But the concept of enablement is used in other contexts in the law of patents (see Biogen Inc v Medeva Plc [1997] RPC 1, 47) and in particular as a ground for the revocation of a patent under section 72(1)(c): "the specification of the patent does not disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art". The question of what will satisfy this test has been discussed in a number of cases. For example, in Valensi v British Radio Corporation [1973] RPC 337, 377 Buckley LJ said:

    "The hypothetical addressee is not a person of exceptional skill and knowledge, that he is not to be expected to exercise any invention nor any prolonged research, inquiry or experiment. He must, however, be prepared to display a reasonable degree of skill and common knowledge of the art in making trials and to correct obvious errors in the specification if a means of correcting them can readily be found."

    There is also a valuable and more extended discussion in the judgment of Lloyd LJ in Mentor Corporation v Hollister Incorporated [1993] RPC 7. In the present case the Court of Appeal was reluctant to say that the test of enablement of a prior disclosure for the purpose of anticipation was the same as the test of enablement of the patent itself for the purpose of sufficiency. But I can think of no reason why there should be any difference and the Technical Board of Appeal has more than once held that the tests are the same: see ICI/Pyridine Herbicides [1986] 5 EPOR 232, para 2; COLLABORATIVE/Preprorennin [1990] EPOR 361, para 15. In my opinion, therefore, the authorities on section 72(1)(c) are equally applicable to enablement for the purposes of sections 2(2) and (3). There may however be differences in the application of this test to the facts; for example, because in the case of sufficiency the skilled person is attempting to perform a claimed invention and has that goal in mind, whereas in the case of prior art the subject-matter may have disclosed the invention but not identified it as such. But no such question arises in this case, in which the application plainly identified crystalline PMS as an embodiment of the invention.

    (c)  Keeping the concepts distinct

    28.  It is very important to keep in mind that disclosure and enablement are distinct concepts, each of which has to be satisfied and each of which has its own rules. As Laddie J said in relation to sufficiency in University of Southampton's Applications [2005] RPC 220, 236:

    "In my view, devising an invention and providing enabling disclosure are two quite different things. Although both may be necessary to secure valid protection, as section 14 of the Act shows, they relate to different aspects of the law of patents. It is very possible to make a good invention but to lose one's patent for failure to make an enabling disclosure. The requirement to include an enabling disclosure is concerned with teaching the public how the invention works, not with devising the invention in the first place".

    29.  For a similar point, see Jacob J in Beloit Technologies Inc v Valmet Paper Machinery Inc [1995] RPC 705, 739. Of course the same disclosure may satisfy both requirements. The prior art description may be sufficient in itself to enable the ordinary skilled man, armed with common general knowledge of the art, to perform the subject-matter of the invention. Indeed, when the prior art is a product, the product itself, though dumb, may be enabling if it is "available to the public" and a person skilled in the art can discover its composition or internal structure and reproduce it without undue burden: see the decision of the Enlarged Board of Appeal in Availability to the Public [1993] EPOR 241, para 1.4.

    30.  Nevertheless, in deciding whether there has been anticipation, there is a serious risk of confusion if the two requirements are not kept distinct. For example, I have explained that for the purpose of disclosure, the prior art must disclose an invention which, if performed, would necessarily infringe the patent. It is not enough to say that, given the prior art, the person skilled in the art would without undue burden be able to come up with an invention which infringed the patent. But once the very subject-matter of the invention has been disclosed by the prior art and the question is whether it was enabled, the person skilled in the art is assumed to be willing to make trial and error experiments to get it to work. If, therefore, one asks whether some degree of experimentation is to be assumed, it is very important to know whether one is talking about disclosure or about enablement.

    31.  An example of laying oneself open to misunderstanding in this way is the famous statement by Lord Westbury LC in Hill v Evans (1862) 31 LJ(NS) 457, 463, which I have quoted above. Lord Westbury said that the person skilled in the art must be able practically to apply the discovery "without the necessity of making further experiments and gaining further information before the invention can be made useful". Was he referring to disclosure or enablement? I rather think he meant disclosure and was saying the same as the Court of Appeal did later in General Tire when it said that the prior disclosure must have planted the flag on the invention. On the other hand, by speaking of the man skilled in the art being "able practically to apply the discovery" he certainly gave the impression that he was talking about enablement, and was so understood by Lord Reid in C Van der Lely NV v Bamfords Ltd [1963] RPC 61,71, when he said, correctly in relation to enablement:

    "Lord Westbury must have meant experiments with a view to discovering something not disclosed. He cannot have meant to refer to the ordinary methods of trial and error which involve no inventive step and are generally necessary in applying any discovery to produce a practical result."

    32.  Likewise, the role of the person skilled in the art is different in relation to disclosure and enablement. In the case of disclosure, when the matter relied upon as prior art consists (as in this case) of a written description, the skilled person is taken to be trying to understand what the author of the description meant. His common general knowledge forms the background to an exercise in construction of the kind recently discussed by this House in Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2005] RPC 9. And of course the patent itself must be construed on similar principles. But once the meanings of the prior disclosure and the patent have been determined, the disclosure is either of an invention which, if performed, would infringe the patent, or it is not. The person skilled in the art has no further part to play. For the purpose of enablement, however, the question is no longer what the skilled person would think the disclosure meant but whether he would be able to work the invention which the court has held it to disclose.

    33.  There is also a danger of confusion in a case like Merrell Dow Pharmaceuticals Inc v H N Norton & Co Ltd [1996] RPC 76, in which the subject-matter disclosed in the prior art is not the same as the claimed invention but will, if performed, necessarily infringe. To satisfy the requirement of disclosure, it must be shown that there will necessarily be infringement of the patented invention. But the invention which must be enabled is the one disclosed by the prior art. It makes no sense to inquire as to whether the prior disclosure enables the skilled person to perform the patented invention, since ex hypothesi in such a case the skilled person will not even realise that he is doing so. Thus in Merrell Dow the question of enablement turned on whether the disclosure enabled the skilled man to make terfenadine and feed it to hay-fever sufferers, not on whether it enabled him to make the acid metabolite.

Applying the law to the facts

    (a)  Disclosure

    34.  Did the Synthon application disclose an invention which, if performed, would infringe the SB patent? Because it covered a class of chemicals defined by reference to a formula, it disclosed a myriad of compounds, each of which may be regarded as an invention. But that does not matter if one of those inventions was the crystalline PMS claimed in the patent.

    35.  There seems to me no doubt that the application disclosed the existence of PMS crystals of 98% purity and claimed that they could be made. Whether in fact they could be made is the question of enablement which I shall come to in a moment. But their existence and their advantages for pharmaceutical use were clearly disclosed in the application. And on the basis of the judge's finding of monomorphism, a PMS crystal of 98% purity must necessarily have all the characteristics of the crystals claimed in the patent, including the IR and XRD spectra.

    36.  Does it matter that the disclosure attributed to PMS crystals an IR spectrum which, on the judge's findings, was wrong? In my opinion it does not. Of course if the crystals were polymorphic, it would be necessary to specify an IR spectrum or some other way of distinguishing between them. The skilled person, having made his crystals, might find that they infringed the patent or they did not, depending upon which kind he had made. If there had been more than one polymorph, he would not have infringed if he had made the one disclosed by the application. But when the crystals are monomorphic, the IR spectrum is a superfluous part of the description. It may be that the skilled person, having successfully made what the application describes, namely PMS crystals of 98% purity, would be puzzled, perhaps even disconcerted, to find that their IR spectrum turned out to be different from what he had been led to believe. But he would have made the crystals and they would necessarily infringe the patent.

    37.  In some contexts one might say that the IR spectrum in the application was a falsa demonstratio which did not prevent the described compound, upon the true construction of the application, from being simply pure crystalline PMS, in the way one might conclude, from various details and circumstantial evidence that a witness was describing a particular motor car, even though his reading of the number plate was inaccurate. That is a perfectly legitimate way of approaching the question. But it is, I think, more easily answered if one remembers the general principle that anticipation requires a prior disclosure which, if performed, would infringe the patent. The subject-matter described was crystalline PMS and a skilled person who performed that invention, though he might, if he had read the patent, think that he was not going to infringe it, would inevitably do so.

    (b)  Enablement

    38.  Once one has decided that the disclosure in the application was crystalline PMS and that the IR spectrum was superfluous and irrelevant, the question of enablement is whether the skilled person would have been able to make crystalline PMS. If he did, he would necessarily have made the product claimed in the patent. There is no dispute that the disclosure enabled him to make PMS. The issue is whether he would have been able to get it to crystallise. That is a question of fact, involving the application of the standards laid down in cases like Mentor Corporation v Hollister Incorporated [1993] RPC 7 to the evidence of the nature of the problem, the assistance provided by the disclosure itself and the extent of common general knowledge. Synthon, as I have said, got off to a bad start by specifying, in their main example, a solvent which proved unsuitable for crystallisation. Nevertheless, the judge found that the skilled man would have tried some other solvent from the range mentioned in the application or forming part of his common general knowledge and would have been able to make PMS crystals within a reasonable time. This is a finding of fact by a very experienced judge with which an appellate court should be reluctant to interfere: compare Biogen Inc v Medeva Plc [1997] RPC 1, 45.

    The Court of Appeal

    39.  The Court of Appeal (Aldous, Sedley and Rix LJJ), in a judgment given by Aldous LJ, reversed the judge's decision. As will appear, I have not found it easy to understand the judgment; I shall have to look at some passages in detail, but the main source of my difficulty is that, with great respect to Aldous LJ, who is an acknowledged master of patent law, the questions of disclosure and enablement are so intermingled that it is often difficult to say which of them he is talking about.

    40.  After referring to some of the authorities, Aldous LJ said:

    "The dispute between the parties essentially involves a dispute of fact, namely what is explicitly and implicitly disclosed in the application. Thereafter, the court has to decide whether that disclosure is sufficient to make the invention of the patent available."

    41.  If that means that there are two questions: first, did the application disclose, explicitly or implicitly, an invention which would, if performed, infringe the patent and secondly, was that invention enabled, then of course I would agree. After setting out the arguments of the parties and saying that clear guidance could be obtained from the General Tire and UNION CARBIDE cases (to which I have referred above) the judge went on:

    "There are no clear and unmistakeable directions to make PMS as claimed in claim 1 of the patent as required by the General Tire case. The general teaching of the application does not mention PMS. It is one of a number of compounds described by reference to formulae. The only specific reference is in example 1. That describes a different form. It follows that the skilled person would not expect to produce the PMS claimed in claim 1 by carrying out the general teaching of the application. If he attempted to carry out example 1, he would fail to obtain crystalline PMS. He would therefore not know that there was only one form of crystalline PMS and that was not the form described in the application."

    42.  I find this passage particularly confusing. What are the "clear and unmistakeable directions to make PMS as claimed in claim 1"? Is this disclosure (ie identifying crystalline PMS as a desirable compound) or does it refer to enablement? If it refers to enablement, does it mean that the disclosure itself must enable? That cannot be right because, as I have said, the disclosure may consist entirely of putting a compound on the market and enablement may be found in the ordinary skilled man's ability to analyse and reproduce it. Likewise, if the problem is crystallisation, the enablement may be found in the armoury of the ordinary skilled man with little, if any, assistance from the disclosure. Then, why does it matter that it is one of a number of compounds identified in the invention and that it is mentioned at a certain point in the application? The question is whether it is disclosed. To say that the application discloses a different form begs the question because there is no different form. Disclosure of crystalline PMS was disclosure of the patented product. The fact that the skilled man, surveying the result of his labours, would have thought he had made a product different from that described in the application seems to me irrelevant.

    43.  The judge next said:

    "Further the teaching is not such that skilled persons would at once perceive, understand and be able practically to apply the invention claimed in claim 1 of the patent without the necessity of doing further experiments. If they sought to produce PMS they would believe that the application led to a different form."

    44.  Again, it seems to me that what they would have believed they were doing when they sought to produce crystalline PMS is as irrelevant as what the takers of terfenadine thought was happening in their livers. Making crystalline PMS would have resulted in the form described in the patent. The judge then went on:

    "If they sought to carry out the specific directions of production, they would fail … The general statements in the application relied on did not disclose any particular method of production of any particular product. To suggest that they did when the specific method did not work is, I believe, fanciful. "

    45.  These sentences appear to be about enablement. But the judge then immediately went on to cite the passage in the UNION CARBIDE case (quoted above) about it being necessary that the prior disclosure should be of an invention which, if performed, will inevitably result in infringement of the patent. But that principle is, as I have explained, concerned with the scope of the disclosure in the prior art; whether it has planted the flag. It is not concerned with the question of enablement.

    46.  The judge later said:

    "The suggestion that the disclosure in the application was equivalent to that in the patent is not correct. As one would expect both contain general statements on production, but they are different. Perhaps with knowledge of the patent, it would be possible to extract the idea to make crystalline PMS and a process to do it other than that in example 1."

    47.  There was in my opinion no need to have knowledge of the patent or anything else to "extract the idea to make crystalline PMS". The idea of making crystalline PMS and its advantages in terms of purity, stability and so forth were plainly disclosed in the application. Whether the skilled person would have been enabled to make it is a separate point.

    48.  Finally, the judge contrasted the two disclosures:

    "The patent is directed at PMS, whereas the application is directed at a large number of compounds both in the general statements and in the preferred form. Secondly, the general statements as to how PMS can be obtained differ from those relating to the compounds in the application. Thirdly, the examples in the patent give detailed instructions as to how crystalline PMS can be made, whereas the equivalent example in the application does not work. Fourthly, the patent claims a different crystalline form of PMS to that described in the application."

    49.  Of these four points, the second and third are relevant to enablement but the first and fourth are, for the reasons I have explained, irrelevant.

    50.  I am therefore left in some uncertainty as to whether or not the Court of Appeal thought that Synthon had failed on the requirement of disclosure, that is, whether they had failed to plant the flag on crystalline PMS as described in the patent. If that was the finding, I think it was wrong.

    51.  I turn therefore to the question of enablement. As I have said, Jacob J relied in part upon his general findings that the processes by which crystallisation is initiated are "far from precisely understood" and "something of an art - part of the skills of an organic chemist". He found support in the attitude taken by the SB patent itself and the evidence of Mr Ward, from whom he quoted the following passage:

    "Q.  If you were looking at [the application] and considering making paroxetine mesylate, you would certainly start with the examples. That is right, is it not?

    A.  Yes, yes, I certainly would.

    Q.  But you certainly would not feel bound by them, would you? You would expect to make paroxetine mesylate using a variety of other reactions and conditions?

    A.  Yes, I think I would.

    Q.  And crystallise it successfully?

    A.  That is perhaps another matter. I think I might be inclined to say 'Once I have actually got some sort of crystals, then I might investigate a better way of making crystalline material'. In order to get your seeds, then it might be sensible to do what is in the document rather than go shooting off and doing your own thing.

    Q.  I think we agree you would start with the examples. You start with the examples. Let us suppose that you perform [the example in the application] and it does not work. What do you do next?

    A.  I think I would do the sort of thing I have mentioned in my expert report. I would look at the chemistry that I was trying to carry out and say 'Well, maybe I need to make some changes'. I think I have suggested the sort of changes I would make. I might well readjust the stoichiometry, the molar equivalents.

    Q.  And you might get a hint that that might be a good idea from looking at [the example], would you not?

    A.  You might and you might not. I am not necessarily convinced by that. In my experience of making salts of bases, it is sometimes actually advantageous to make the first sample with an excess of acid. This is frequently done with things like hydrochloride salts. I am not necessarily convinced that you would necessarily always go down in molarity.

    Q.  You might go up?

    A.  You might go up, yes. You might change the concentration; you might change the solvent.

    Q.  But these would all be straightforward changes, and you would expect, fairly quickly, to succeed, based on what is in this document?

    A.  I would certainly have an expectation of success, yes."

    52.  Having quoted this evidence, Aldous LJ said that it —

    "does not establish that the application contains the clear and unmistakeable directions to make the claimed form of PMS".

    Again I find it difficult to say whether the judge is concerned with disclosure or enablement. The reference to "the claimed form of PMS" suggests that he is still preoccupied with the difference in IR readings, which is a matter of disclosure and is, as I have said, irrelevant. The judge went on to say that Mr Ward was one of the inventors of the patent and had "more knowledge of making PMS than the skilled person would have had". That is true, but Jacob J was well aware of the dangers of reasoning from what a highly skilled person would do (he said of the evidence of Sir Jack Baldwin: "one is concerned with the ordinary skilled man or team, not world champions") and the fact that Mr Ward discovered the properties of PMS does not mean that he could not give evidence of what would be conventional practice in dealing with problems of crystallisation. He agreed that the kind of experimentation being put to him consisted of "straightforward changes".

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