The case was reported in The Times 27 October, 1995. The following commentary is, however, based on a transcript of the case supplied by the Judicial Office of the House of Lords.

Facts

Proceedings

Novelty under the Patents Act 1977

Judgment

The Significance of the European Patent Convention

Anticipation by use

Anticipation by disclosure

The MOBIL Case

Analysis
General Principles

The European Patent Convention and the 1977 Act

The MOBIL Case and the Rejection of a Doctrine of Inherency

The MOBIL Case and a New Use for an Old Product

Bibliography

Facts

Subsequent to the granting of the patent for terfenadine, Merrell Dow conducted research into the mechanism underlying its effects in humans. They discovered that terfenadine, once ingested, was rapidly and almost completely metabolised in the liver, to produce a complex acid. It was this resulting acid metabolite that was almost exclusively responsible for the anti-histamine effects displayed following the ingestion of terfenadine. This acid metabolite had not been previously identified, and was patented as claim 24 of a patent granted to Merrell Dow in 1980 (Patent number 2042258). The acid metabolite patent was due to expire in the year 2000.

In January 1982 a symposium was held at which Merrell Dow made public the results of their research into terfenadine and its effects.

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Proceedings

Subject to the following provisions of this section, a person (other than the proprietor of the patent) also infringes a patent for an invention if, while the patent is in force and without the consent of the proprietor, he supplies or offers to supply in the United Kingdom a person other than a licensee or other person entitled to work the invention with any of the means, relating to an essential element of the invention, for putting the invention into effect when he knows, or it is obvious to a reasonable person in the circumstances, that those means are suitable for putting, and are intended to put, the invention into effect in the United Kingdom.

Merrell Dow commenced two actions for infringement against other pharmaceutical companies supplying terfenadine. The respondents contended that the patent was invalid and counterclaimed that the patent should be revoked under the Patents Act 1977 s 72. Several grounds for invalidity were initially put forward, however their Lordships addressed only the contention that, so far as the claim to the acid metabolite included its manufacture by the metabolising of terfenadine in the human body, the patent was invalid for lack of novelty. It was on this ground that the action was initially dismissed by Aldous J, (Merrell Dow Pharmaceuticals Inc and Another v H N Norton & Co Ltd [1994] RPC 1), this decision being subsequently affirmed by the Court of Appeal (Merrell Dow Pharmaceuticals Inc and Another v H N Norton & Co Ltd [1995] RPC 233, CA). For commentaries on these decisions see Karet 1993 and Karet 1994 respectively.

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Novelty under the Patents Act 1977

(1) An invention shall be taken to be new if it does not form part of the state of the art.

(2) The state of the art in the case of an invention shall be taken to comprise all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way.

The appellants (Merrell Dow) argued that the 1977 Act had overturned previous principles of UK law. They contended that under the 1977 Act, the definition of "state of the art" in s 2(2) requires not that something had been done before, but that information about what had been done should have been made available to the public. In this particular case it was argued that no information about the acid metabolite had been available to the public before the priority date of its patent.

On the other hand, the respondents argued that the acid metabolite was not new within the meaning of s 2(2) for two reasons. First, it had been used before the priority date (adopting traditional English terminology, this argument may be referred to as anticipation by use). This argument was founded on the assumption that the acid metabolite had been made in the livers of volunteers during clinical tests of terfenadine in 1977/78. Secondly, it was argued that the invention had been disclosed in the specification of the terfenadine patent. This specification detailed the manufacture of terfenadine and that it should be taken for its anti- histamine effects. The inevitable result of following the instructions contained in the specification would be to make the acid metabolite. This argument may be referred to as anticipation by disclosure.

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Judgment

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The Significance of the European Patent Convention

(1) An invention shall be considered to be new if it does not form part of the state of the art.

(2) The state of the art shall be held to comprise 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.

For the purpose of construing the provisions of the Patents Act 1977 s 2, Lord Hoffmann considered that regard must therefore be taken of the decisions of the European Patent Office [hereinafter the EPO] on the construction of the EPC. He acknowledged that while these decisions were not technically binding upon UK courts, they were of great persuasive authority for the following reasons:

"[F]irst because they are decisions of expert courts (the Boards of Appeal and Enlarged Board of Appeal of the EPO) involved daily in the administration of the EPC and secondly, because it would be highly undesirable for the provisions of the EPC to be construed differently in the EPO from the way they are interpreted in the national courts of a Contracting State."

His Lordship then proceeded to address the arguments in respect of anticipation by use and anticipation by disclosure separately.

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Anticipation by use

However, his Lordship felt that Bristol-Myers could no longer be considered good law. If regard is had to Article 54 of the EPC it becomes clear that to be part of the state of the art, the invention must have been made available to the public. He continued:

"An invention is a piece of information. Making matter available to the public within the meaning of section 2(2) therefore requires the communication of information. The use of a product makes the invention part of the state of the art only so far as that use makes available the necessary information."

Lord Hoffmann found support for this construction of s 2(2) in the judgment of Aldous J in PLG Research Ltd and another v Ardon International Ltd and others [1993] FSR 197 where it was said (at 225):

"Mr Thorley submitted that if a product had been made available to the public, it was not possible thereafter to patent the product whether claimed as a product claim or a product-by-process claim. That submission is too broad. Under the 1977 Act, patents may be granted for an invention covering a product that has been put on the market provided the product does not provide an enabling disclosure of the invention claimed. In most cases, prior sale of the product will make available information as to its contents and its method of manufacture, but it is possible to imagine circumstances where that will not happen. In such cases a subsequent patent may be obtained and the only safeguard given to the public is section 64 of the Act."

Support was also to be found in Decision G02/88 MOBIL/Friction reducing additive [1990] EPOR 73 where the Enlarged Board of Appeal of the EPO stated (at 88):

"[T]he Enlarged Board would emphasise that under Article 54(2) EPC the question to be decided is what has been ‘made available’ to the public: the question is not what may have been ‘inherent’ in what was made available (by prior written description, or in what has previously been used (prior use), for example). Under the EPC, a hidden or secret use, because it has not been made available to the public, is not a ground of objection to [the] validity of a European patent. In this respect, the provisions of the EPC may differ from the previous national laws of some Contracting States, and even from the current national laws of some non-Contracting States. Thus, the question of ‘inherency’ does not arise as such under Article 54. Any vested right derived from prior use of an invention is a matter for national law...."

It was therefore concluded by his Lordship that Merrell Dow's claim could not be dismissed simply on the ground that making the acid metabolite was something which had been done before.

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Anticipation by disclosure

Merrell Dow's research revealed that ingestion of terfenadine led to something being produced in the liver which could be given a chemical description. However Lord Hoffmann noted that the same thing may be known under one description and not known under another and further that there was an infinite variety of descriptions under which the same thing may be known. Supporting his argument with examples, he observed that there are descriptions under which something may be known without anyone being aware of its chemical composition. His Lordship continued:

"Section 2(2) does not purport to confine the state of the art about products to knowledge of their chemical composition. It is the invention which must be new and which must therefore not be part of the state of the art. It is therefore part of the state of the art if the information which has been disclosed enables the public to know the product under a description sufficient to work the invention."

It was acknowledged by his Lordship that for most of the purposes of a product claim, knowledge of its chemical composition would be necessary to enable the public to work the invention. The appellants had sought to rely on Decision GO1/92 Availability to the Public [1993] EPOR 241 in which the Enlarged Board of Appeal held that the composition or internal structure of a product became part of the state of the art if it was possible for a skilled person to discover it and reproduce it without undue burden. However, Lord Hoffmann observed that the Board in this case addressed the circumstances in which the chemical composition of a product became part of the state of the art. What the Board had not considered were the circumstances in which knowing the chemical composition was necessary for the purpose of treating a product as part of the state of the art. Thus, he concluded, this decision could not, as was suggested by the appellants, be used as authority for the proposition that in no context can a product be part of the state of the art unless its chemical composition is known.

Rather, Lord Hoffmann continues, other decisions of the EPO indicate that, at least for some purposes, products need not be known under their chemical description in order to be part of the state of the art. Support for this conclusion could be found in the decision of the Technical Board of Appeal in Decision T12/81 BAYER/Diastereomers [1979-85] EPOR Vol B 308, where the Board said (at 312):

"[T]he concept of novelty must not be given such a narrow interpretation that only what has already been described in the same terms is prejudicial to it. The purpose of Art. 54(1) EPC is to prevent the state of the art being patented again. Art 54(2) EPC defines the state of the art as comprising everything made available to the public before the date of filing in any way, including by written description. There are many ways of describing a substance in chemistry and this is usually done by giving its precise scientific designation. But the latter is not always available at the date of filing. . . [It] is the practice of a number of patent offices to accept the process parameter, in the form of a product-by-process claim, for closer characterisation of inventions relating to chemical substances. To the Board's knowledge this is also the practice at the European Patent Office. If inventions relating to chemical substances defined by claims of this kind are patented, it necessarily follows that the resulting patent documents, once they enter the state of the art, will be prejudicial to the novelty of applications claiming the same substance although in a different and perhaps more closely defined form."

Lord Hoffmann concluded that "if the recipe which inevitably produces the substance is part of the state of the art, so is the substance as made by that recipe". He also referred to the Technical Board's finding in Decision T303/86 CPC/Flavour Concentrates [1989] 2 EPOR 95 (which involved an application to patent a process for making flavour concentrates which was challenged on the basis that certain cook-book recipes disclosed, in non-technical terms, processes having the same effect). In CPC/Flavour Concentrates, the Technical Board stated (at 98):

"It is sufficient to destroy the novelty of the claimed process that this process and the known process are identical with respect to starting material and reaction conditions since processes identical in these features must inevitably yield identical products."

Lord Hoffmann observed that the Board in this case proceeded on the basis that, for the purpose of being part of the state of the art, a process for making flavour concentrates was sufficiently described by a recipe for cooking which did not expressly refer to the flavour concentrates, but nevertheless, would inevitably have the effect of making them.

Applying these principles derived from the decisions of the EPO, it was concluded by Lord Hoffmann that the description contained in the terfenadine specification made available to the public knowledge sufficient to work the invention by making the acid metabolite in their bodies:

"[K]nowledge of the acid metabolite was in my view made available to the public by the terfenadine specification under the description ‘a part of the chemical reaction in the human body produced by the ingestion of terfenadine and having an anti-histamine effect.’ Was this description sufficient to make the product part of the state of the art? For many purposes, obviously not. It would not enable anyone to work the invention in the form of isolating or synthesising the acid metabolite. But for the purpose of working the invention by making the acid metabolite in the body by ingesting terfenadine, I think it plainly was. It enabled the public to work the invention by making the acid metabolite in their livers. The fact that they would not have been able to describe the chemical reaction in these terms does not mean that they were not working the invention. Whether or not a person is working a product invention is an objective fact independent of what he knows or thinks about what he is doing."

However, his Lordship went on to qualify the conclusion that "whether or not a person is working a product invention is an objective fact." Referring to the decision of the Enlarged Board of Appeal in the MOBIL case, he noted that the position may be different when the invention is a use for a product and that in such a case a person may only be working the invention when he is using it for the patented purpose. Lord Hoffmann then went on to discuss the MOBIL case in some detail.

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The MOBIL Case

Instead, Lord Hoffmann noted that Merrell Dow had sought to rely on MOBIL only in respect of that part of the decision in which the Enlarged Board of Appeal rejected a "doctrine of inherency" (see above under the heading "anticipation by use"). Lord Hoffmann fully accepted this principle, and had applied it in rejecting the respondent's claim based on anticipation by use. However:

"[T]he argument in this appeal for anticipation by disclosure involves no ‘doctrine of inherency.’ It does not claim that the acid metabolite must be deemed to have been made available by the teachings of the terfenadine patent even though all information about it remained hidden. It claims instead that the acid metabolite was sufficiently disclosed under the description ‘an anti-histamine chemical reaction in the human body which occurs after taking terfenadine.’ The respondents say that for the purposes of the particular invention in issue, the specification contained sufficient information about the acid metabolite to make it part of the state of the art. For the reasons I have given, I think it did."

Lord Hoffman therefore dismissed the appeal.

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Analysis

General Principles

What is essentially the same general rule is sometimes slightly differently expressed as the rule that a patent cannot be used to stop someone doing what he had done before. Thus, Oliver LJ, in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59, CA states (at 77): "the notion behind anticipation is...that it would be wrong to enable the patentee to prevent a man from doing what he has lawfully done before" and in Bayer/Diastereomers, the Board of Appeal observed (at 312) that the purpose of Article 54 of the EPC is "to prevent the state of the art being patented again".

These two formulations may be referred to as the "post-infringement" and "right to work" tests respectively (adopting the terminology used by White 1990).

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The European Patent Convention and the 1977 Act

Their Lordships make it clear that as regards the interpretation of those sections of the Patents Act 1977 intended to have the same effect as the corresponding provisions of the EPC (listed in s 130(7)), UK courts must go beyond a mere examination of the EPC and must consider the construction given to the relevant provisions by the EPO. Their Lordships add that such decisions must be considered to be of great persuasive authority.

The traditional national philosophies underlying patent protection differ among the Member States of the Convention (as noted by the Enlarged Board of Appeal of the EPO in MOBIL, ([1990] EPOR 73, at 78)). Given these differences, there is a genuine danger that national courts, if they chose not to refer to the decisions of the EPO, could reach different conclusions on the proper construction of the EPC. Placing reliance on the decisions of the EPO will tend to counteract this potential divergence and as such is a sensible approach. If adopted by the national courts of all Member States, this approach will facilitate a convergence of jurisprudence throughout these States. Furthermore, since the grant of a European patent provides an alternative to a national patent application, it is desirable that the national system is essentially the same as the European system. To achieve such consistency, UK courts, in interpreting the 1977 Act, should follow as closely as possible the interpretation of the EPC adopted by the EPO. It may be noted that in their reasoning in the instant case, their Lordships relied almost exclusively on decisions of the EPO.

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The MOBIL Case and the Rejection of a Doctrine of Inherency

An approach to interpretation which aims to avoid differences of approach between the laws of the various Member States of the EPC, logically requires an acknowledgement that, in principle at least, the 1977 Act may have changed some long-standing and fundamental principles of UK patent law. Their Lordships have embraced such a notion. Thus, in commenting on the new law as it applies to an uninformative use before the priority date, Lord Hoffmann notes that:

"The 1977 Act...introduced a substantial qualification into the old principle that a patent cannot be used to stop someone doing what he had done before. If the previous use was secret or uninformative, then subject to section 64, it can. Likewise, a gap has opened between the tests for infringement and anticipation. Acts done secretly or without knowledge of the relevant facts, which would amount to infringements after the grant of the patent, will not count as anticipations before."(3)

It is hard to see how their Lordships could have interpreted s 2 otherwise given the emphasis they place on the duty to examine the corresponding provisions of the EPC and given the decision by the Enlarged Board of Appeal in MOBIL, that under Article 54(2) EPC the question to be decided is what has been made available to the public, not what may have been inherent in what was made available. It may be noted however that at first instance Aldous J considered that the MOBIL case had no direct relevance since the Board in making that decision had in mind a "use claim" and not a claim to a product per se. Furthermore, in the Court of Appeal, the Vice Chancellor observed that the instant case differed from MOBIL in a crucial respect. In MOBIL the claim (for a new use of an old compound) would not have prevented others from using the compound as before, for its known purposes. In the instant case however, the acid metabolite patent would prevent others from using terfenadine as before, for its known purpose. Accordingly, in rejecting the inherency argument, the Board did not have in mind this different situation.

Article 54(2) EPC does not differentiate between matter made available by use or description, and thus the same test of novelty should apply to both. This was made clear by the Enlarged Board of Appeal in MOBIL where they stated (at 87-88 ):

"Article 54(2) EPC defines the state of the art as comprising ‘everything made available to the public by means of a written or oral description, by use, or in any other way’. Thus, whatever the physical means by which information is made available to the public (eg written description, oral description, use, pictorial description on a film or in a photograph etc, or a combination of such means), the question of what has been made available to the public is one of fact in each case."

"The word 'available' carries with it the idea that, for lack of novelty to be found, all the technical features of the claimed invention in combination must have been communicated to the public or laid open for inspection."

Thus, in accepting that there can be no doctrine of inherency in the case of anticipation by use, this principle must be equally applicable in the case of anticipation by disclosure. Their Lordships concluded however, that although the principle was applicable in both cases, the argument raised in the instant case for anticipation by disclosure involved no doctrine of inherency. Their Lordships highlighted, in the following terms, the distinction between the case for anticipation by use, which was rejected, and the case for anticipation by disclosure, which was accepted:

"In both cases no one was aware that the acid metabolite was being made. In the case of anticipation by use, however, the acts relied upon conveyed no information which would have enabled anyone to work the invention, ie to make the acid metabolite. The anticipation in this form relies solely upon the fact that the acid metabolite was made. . . It disavows any reliance upon extraneous information, such as the formula for making terfenadine and the instructions to take it for its anti-histamine effect. Anticipation by disclosure, on the other hand, relies upon the communication to the public of information which enables it to do an act having the inevitable consequence of making the acid metabolite. The terfenadine specification teaches that the ingestion of terfenadine will produce a chemical reaction in the body and for the purposes of working the invention in this form, this is a sufficient description of the making of the acid metabolite. Under that description the acid metabolite was part of the state of the art."

As noted above, the "right to work" and "post-infringement" tests serve to protect against the law treating alleged infringers unfairly. However, the qualification of these tests, in circumstances where the previous use was secret or uninformative, is not without benefit. In particular this approach is similar to that under US patent law, where the "right to work" test is subordinated to the public policy that inventors have to be encouraged to seek patent protection for their discoveries (White 1990, p 319).

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The MOBIL Case and a New Use for an Old Product

In the MOBIL case, Mobil had attempted to patent an additive to lubricating oil that functioned to reduce friction between moving parts of engines. The opponent showed that this additive was already known and used for inhibiting rust formation. This information ended the possibility of a successful product claim, however Mobil applied to amend their claim to the use of the substance for reducing friction, saying that the additive's usefulness for reducing friction was not previously appreciated. The Technical Board of Appeal referred the following question, amongst others, to the Enlarged Board ([1990] EPOR 73, at 75):

"Is a claim to the use of a compound for a particular non-medical purpose novel for the purpose of Article 54 EPC, having regard to a prior publication which discloses the use of that compound for a different non-medical purpose, so that the only novel feature in the claim is the purpose for which the compound is used?"

In reply, the Enlarged Board of Appeal gave the following answer (at 89):

"With respect to a claim to a new use of a known compound, such new use may reflect a newly discovered technical effect described in the patent. The attaining of such a technical effect should then be considered as a functional technical feature of the claim (for example, the achievement in a particular context of that technical effect). If that technical feature has not been previously made available to the public by any of the means as set out in Article 54(2) EPC, then the claimed invention is novel, even though such technical effect may have inherently taken place in the course of carrying out what has previously been made available to the public."

Thus even though the public had enjoyed the benefit of the friction reducing effect whenever the prior disclosure had been worked, the Enlarged Board deemed that this benefit had not been previously made available to them. It is this feature of the Enlarged Board's decision that has led to the criticism in respect of the difficulties it creates in the application of the traditional UK doctrine of infringement (for examples see Vitoria et al 1995, p 1105 and White 1990, p 320). In such cases, the continued application of absolute liability for infringement destroys the "right to work" and "post-infringement" tests with a consequent potential for unfairness. For example, the seller of an old composition, albeit unwittingly, selling a composition with a friction-reducing additive becomes an infringer. On the other hand, it may be argued that, preserving the principle that the tests for anticipation and infringement are coextensive, if the test for anticipation before the priority date is subjective, then infringement must also be subjectively assessed. This approach also creates problems. An example given by Vitoria (Vitoria et al 1995, p 1105) is the situation in which the trader sells his composition without any indication of the friction-reducing property, but his customers (to his knowledge) buy it for this purpose. It may be noted that in MOBIL, the Enlarged Board did not address the question of infringement.

Lord Hoffmann recognised the problems created by this aspect of the MOBIL decision and noted that under UK law liability for infringement is absolute, depending solely upon whether the act in question falls within the claim. The state of mind of the infringer is thus irrelevant. In the case of a patent for the use of a known substance in a known way for a new purpose Lord Hoffmann considered that applying this doctrine of infringement may be difficult: "[h]ow does one tell whether the person putting the additive into his engine is legitimately using it to inhibit rust or infringing by using it to reduce friction?"

The MOBIL decision raises the question of whether a test for novelty should be objective or subjective. In respect of claims for products per se, their Lordships, relying on the decisions of the EPO in Bayer/Diastereomers and CPC/Flavour Concentrates conclude that the correct test is objective. Whether a person is working an invention is simply a question of fact. Although their Lordship's reasoning is based on the case law of the EPO, the conclusion is in accord with traditional UK principles. However, their Lordships concede that the situation may be different where the claim is a use for a product. In such cases, following the MOBIL decision, a person may only be working the invention when he is using it for the patented purpose and thus the appropriate test becomes subjective. However, their Lordships suggest that even in such cases, such a subjective test would be difficult, if not impossible to apply.

Thus, while acknowledging the desirability for a convergence of European and national jurisprudence, and to this end, accepting that certain fundamental national principles may need to be reconsidered, their Lordships nevertheless consider that future national and European systems must be founded on sound and workable principles.

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Karet, (1993) 'Prior Written Disclosure and Prior Use under English Law. Merrell Dow v Norton' 15 (11) European Intellectual Property Review 416.

Karet, (1994) 'Novelty under English Law. Appeal in Merrell Dow v Norton' 16(5) European Intellectual Property Review 204.

Vitoria, M; Jacob, R; Cornish, W; Clark, F; Alexander, D and Tappin, M, (1995) Encyclopaedia of United Kingdom and European Patent Law (Release 38) (London: Sweet and Maxwell).

White, (1987) 'The Novelty-Destroying Disclosure: Some Recent Decisions' 9 European Intellectual Property Review 315

Footnotes

(1) Officially the Convention on the Grant of European Patents (European Patent Convention). Signed in Munich on 5 October 1973, the UK instrument of ratification was deposited on 3 March 1977 and the Convention entered into force on 7 October 1977. Back to text

(2) For example, European patents must be accorded a term of twenty years from the date of filing of its application (Articles 63 and 167(1)(c) EPC); they may only be revoked on the grounds specified in the Convention (Articles 138 and 139 EPC) and they must be treated as giving rise to rights specified in the Convention (Articles 64-70 EPC). Back to text

(3) As noted by their Lordships, these conclusions, that a prior secret or uninformative use will not anticipate a claim are qualified by the provisions of s 64. However the scope of this section is somewhat limited. Section 64(1) essentially provides that where a patent is granted for an invention, a person who before the priority date of the invention, does in good faith an act which would constitute an infringement of the patent if it were in force, has the right to continue to do the act. It is important to note that s 64 protects only that which was done in good faith before the priority date. Thus s 64 cannot be relied upon if acts carried out before the priority date are subsequently modified or developed. Back to text