Napp Pharmaceutical Holdings Ltd v Ratiopharm GmbH

This is the judgment of the court to which all members have contributed.

We have an appeal (argued by Mr Michael Tappin) and cross-appeal (argued by Mr Michael Silverleaf QC) from a judgment of Floyd J of 16^th December 2008. The appeals were expedited because the generic medicine parties, ratiopharm GmbH and Sandoz Limited (collectively “r/S”), are about to receive a marketing authorisation. Determining a case on its full merits quickly generally means that there is no need for any provisional measures or the legal costs and time which would otherwise be devoted to them. That was so here.

The patentees are Napp Pharmaceutical Holdings Ltd. Napp owns the two patents in suit, Nos. EP (UK) 722730 and 1258246. The Judge held both patents valid but not infringed by the tablets which r/S wish to sell, a product made by Cimex AG (now Acino AG). Below it was called “the Cimex product” and we will do the same.

The patents relate to controlled release formulations of a painkiller called oxycodone. Napp sells such a formulation under the trade mark OxyContin. Its importance is shown by its sales figures – of the order of £32 million per annum in the UK alone.

OxyContin is a painkiller used as an alternative to morphine for moderate to severe pain. It has certain advantages as compared with morphine. r/S’s own expert witness, Professor Bennett said, as recorded by the Judge at [258], that “it formed a valuable weapon in the armoury of the pain management clinician working in palliative care or otherwise.”

Even if the decision that the Cimex product does not infringe were upheld it would be necessary to consider validity. Bifurcation of the issues of infringement and validity would serve no useful purpose. This is because Sandoz has another product in the pipeline which it is said infringes some of the claims of the 730 patent. We do not know whether it does or not: there is an infringement action pending.

The two patents have, for practical purposes, the same text because they are “divisionals.” The differences lie in their respective claims, and in variations of the text consequential upon the dividing out process. For present purposes it is common ground, as it was below, that we can work mainly from the text of 730.

We should say a word about “divisionals.” The basic procedure for applying for a patent is laid down in Art. 75 of the EPC. This allows an inventor to apply for a patent by filing his/her application at the EPO (or a national office of an EPC member if the law of that state allows it). The relevant date for the purposes of judging patentability (the “priority date”) will be the date of that application, though an earlier priority date may be claimed if the patentee has made an earlier (but within one year) application in a Paris Convention country. The application can be made to the EPO via the machinery of the Patent Co-Operation Treaty (PCT). That was used to make the application leading to the patents in suit in this case.

However Art 76 of the EPC allows for an elaboration of the basic procedure. It goes by the jargon “divisional”. Art 76 says:

76(1) A European divisional application must be filed directly with the European Patent Office at Munich or its branch at The Hague. It may be filed only in respect of subject-matter which does not extend beyond the content of the earlier application as filed; in so far as this provision is complied with, the divisional application shall be deemed to have been filed on the date of filing of the earlier application and shall have the benefit of any right to priority.

So what a patentee can do, having made an initial application, is to apply for a divisional patent. Provided the subject-matter of this does not extend beyond the content of the earlier application, he can get a free-standing patent for the divisional application. Because the date of filing is deemed to be that of the “parent” as the jargon goes, a patentee cannot extend the period of protection by applying for a divisional.

Sometimes the EPO will say to a patentee that he has got too much in a single application (an application can only cover a single invention or group of inventive concepts, Art.82) and he must divide out or cut down. But a divisional can be sought by a patentee even if the Office does not require it. Then the patentee’s purpose is to break up his/her original application into a cluster of sister patents – each having the same basic disclosure but with different claims. Much the same could be achieved by just adding these claims to the original application, but there are both real and perceived advantages in using divisionals. Firstly each patent will stand or fall on its own merits whereas otherwise there is a risk of the complications of a partially valid patent – complications with potentially different results in different Member States. Secondly a possible infringer can be sued on just the divisional(s) relevant to what he does. Thirdly if the patentee is having trouble with the examination process in respect of part of his invention, he may divide out the portion which the Office accepts is all right so that it gets early grant of that, and meanwhile he can pursue his argument with the Office in respect of the remainder.

It is fair to say that a clutch of divisionals is likely to make the position more difficult to assess for third parties. Here for instance there are no less than nine divisionals stemming from the original application. It is perhaps questionable as to whether the current voluntary aspect of the divisional system should continue to be permitted. That is particularly so since one of its justifications has now gone or is of less significance. A patentee need no longer fear that by having all his claimed eggs in one basket, he will lose his patent if even one egg turns out to be bad: central amendment of a granted patent is now possible pursuant to the provisions of Art.105a of the EPC (introduced by amendment pursuant to the EPC 2000).

One of the features of the divisional system is that each divisional must have claims which are different: the patentee cannot have the same claim in different patents. So filing a divisional involves a dividing up process: what is claimed in the divisional must be excluded from the claims of the patent from which it has been divided out. That dividing out process may, perhaps, itself add subject-matter – it is said to have done so in this case.

The Judge describes this uncontroversially at [8] to [25]. To summarise:

Broadly, the two patents in suit are for a 12-hour controlled release form of oxycodone. The claims alleged to be infringed by the Cimex product are for barrier-type controlled release forms. The barrier-type form specifically described is made by the use of extrusion spheronisation, one of a number of well-known way of making small spherical particles. The description also includes matrix-type forms – no doubt they form the subject of one or more of the divided out patents as well as some claims of the 730 patent.

The Judge describes the 730 patent at [35]-[49], citing a number of passages which are of significance in relation to claim construction. We will come to them at that point in our judgment. For present purposes it is important to note what the inventors say is the real point of their invention. It is effectively contained in two main passages, though there are also others cited by the Judge:

[21] It has now been surprisingly discovered that the presently claimed controlled release oxycodone formulations acceptably control pain over a substantially narrower, approximately four-fold (10 to 40 mg every 12 hours – around the- clock dosing) in approximately 90% of patients. This is in sharp contrast to the approximately eight-fold range required for approximately 90% of patients for opioid analgesics in general.

[23] Morphine, which is considered to be the prototypic opioid analgesic, has been formulated into a 12 hour controlled release formulations (i.e. MS Contin® tablets commercially available from Purdue Pharma, L.P). Despite the fact that both controlled-release oxycodone and controlled release morphine administered every 12 hours around-the-clock possess qualitatively comparable clinical pharmacokinetic characteristics, the oxycodone formulations of the presently claimed invention can be used over approximately 1/2 the dosage range as compared to commercially available controlled release morphine formulations (such as MS Contin®) to control 90% of patients with significant pain.

These two passages along with the other passages are saying two things: that a 12-hour slow release oxycodone is as good at killing pain as morphine and that it needs less titration compared with a slow release morphine because there is less patient-to-patient variation. Although the latter advantage was challenged and the Judge was not satisfied that it is so, the former was not – and as we have said the invention has in fact proved to be a valuable alternative to slow release morphine.

Turning to the claims of the patents it is only necessary to set out those relevant to our decision (the Judge set out rather more claims in an annex). Those claims are:

Because there were a surprisingly large number of issues raised on the appeal, we asked the parties to provide an agreed list of issues in advance of the hearing. This proved to be helpful. We do not set it out here, preferring to set out each issue as we come to it.

And also before coming to the issues of construction, to explain why they are issues, it is helpful to describe the alleged infringing product, the Cimex tablets. We borrow with gratitude the Judge’s description:

[98] The Cimex product which is accused of infringement is a tablet which contains, embedded in excipients, small particles made up of a number of layers. A cross section of a particle showing the layers is shown below.

[99] The Core is bought in by Cimex. It is made from sugar crystals which are built on with liquid glucose and corn starch in a standard coating vessel from which they are taken and dried. The Inner Layer is made up of oxycodone hydrochloride (83 wt%), hydroxypropylmethyl cellulose (HPMC, about 8 wt%) and talc/macrogol (about 9 wt%). It is sprayed onto the cores in a fluid bed processor.

[100] The Polymer Layer contains ethyl cellulose, hydroxypropylcellulose and propylene glycol. It is accepted by ratiopharm/Sandoz that the Polymer Layer controls the release of the oxycodone hydrochloride in the Inner Layer.

[101] The Outer Layer contains about 96 wt% oxycodone hydrochloride and about 4 wt% HPMC. About 20% of the total weight of oxycodone hydrochloride in the dosage form is in the Outer Layer.

In brief, therefore, 20% of the oxycodone is on the outside of the particles and 80% is within. The 20% will be released more or less immediately whereas the 80% will be slow-released through the polymer layer. By contrast (apart from the fact that the particles are made by a different process, involving building them up from non-pareil beads) the key difference from what is specifically described in the patents is that in the latter all the oxycodone is inside a polymer layer and will be control-released. In the course of argument, the difference was likened to ordinary as opposed to chocolate coated Smarties (M&M’s to some readers).

r/S did not admit that the Cimex tablets comprised “spheroids” or a “spheronising agent”. They pleaded that the term “spheroids” denoted spherical granules manufactured by spheronisation and that none of the excipients constituted a “spheronising agent”. The inner and outer layers contain HPMC, about 8 wt% and 4 wt% respectively. They say that the water-soluble HPMC serves as a binder and is not a spheronising agent.

The Judge accepted that there were a number of ways in which spheroids could be made. They included the process of extrusion/spheronisation in which the active ingredient and excipients are passed through an extruder to produce cylindrical pieces of material. In that process, a spheronising agent was a material which gave the mass of material the right degree of plasticity when it was extruded to allow the second stage of the process to take place in an optimum way.

On the meaning of “spheroid” the Judge concluded ([at 80])

“… the skilled reader would have no reason to think that the term ‘granule’ was being used in any particularly limited sense. He would know that a wide range of processes exist for arriving at a spheroidal particle by agglomerating smaller particles. He would have no reason to suppose that the patentee wanted to exclude any of them.”

The Judge recorded the submission on behalf of r/S that (a) the term “spheronising agent” referred to non-water soluble materials (such as microcrystalline cellulose) which were incorporated to give the correct degree of plasticity in an extrusion/spheronisation process; or (b) the term was limited to agents which had assisted in making a sphere out of something that was not a sphere. He concluded that he preferred r/S’s submission, but concentrated on the second way in which they had put the argument, and found that the claim was using the term “spheronising agent” in the sense of an agent which had enabled the excipients to form into a sphere, and that it could not properly be applied to materials which were added once the sphere was formed. Otherwise the claim would extend to a whole host of materials which the skilled person would never dream of calling spheronising agents as they had played no significant role in the formation of the sphere.

r/S challenge, albeit faintly, the Judge’s conclusion that “spheroid” means spherical granule (the latter being an aggregated particle made up of smaller particles) made by any process. They say he “should have held that spheroids mean spheroids produced by a process of spheronisation using a spheronising agent.” This followed, they suggest, from their main submission (accepted by the Judge) about the limited meaning of “spheronising agent”.

Napp appeals against the Judge’s conclusion on “spheronising agent” for the following reasons. First, “spheronising agent” is widely defined in the specification (para [42]). Second, HPMC is known as an agent for producing spheroids in, for example, the rotorgranulation process. Third, it performs that function in the production of the Cimex product by assisting in making the spheroid (and the core is not the spheroid of the claims). Fourth, that conclusion was not affected by the fact that it also functioned as a binder.

Mr Silverleaf supports the Judge’s reasoning by reference to the following matters in particular. First, HPMC is water-soluble and unsuitable for use as a spheronising agent. The specification draws a clear distinction between the spheronising agent and the binder. The former is non-water soluble ([41]) whereas the latter is exemplified by reference to water-soluble polymers ([44]). Second, on Napp’s approach, any additive used in a rotorgranulation process would qualify as a spheronising agent including water. Third, as regards the Cimex product, it defies common sense to characterise the process of building up a particle on a pre-existing spherical core by spray-coating as a process of spheronisation: the reason that the pellets are spherical is because they start with a spherical sugar core, not because of the HPMC or any other element of the Inner Layer.

We set out those paragraphs of the specification which assist in this aspect of claim construction:

[0041] … In particularly preferred embodiments of this aspect of the invention, the present dosage form comprises film coated spheroids containing active ingredient and a non-water soluble spheronising agent …

[0042] The spheronising agent may be any pharmaceutically acceptable material that, together with the active ingredient, can be spheronised to form spheroids. Microcrystalline cellulose is preferred.

[0043] … According to a preferred aspect of the present invention, the film coated spheroids contain between 70% and 99% (by wt), especially between 80% and 95% (by wt), of the spheronising agent, especially microcrystalline cellulose.

[0044] In addition to the active ingredient and spheronising agent, the spheroids may also contain a binder. Suitable binders, such as low viscosity, water soluble polymers, will be well known to those skilled in the pharmaceutical art …

[0051] The present solid, controlled release, oral dosage form may also be prepared, in the form of film coated spheroids, by

(a)

blending a mixture comprising oxycodone or a oxycodone salt and a non-water soluble spheronising agent,

(b)

extruding the blended mixture to give an extrudate,

(c)

spheronising the extrudate until spheroids are formed, and

(d)

coating the spheroids with a film coat.

The Judge was clearly right about the meaning of “spheroid.” There is no purposive reason to limit it as suggested, and every purposive reason to say it means any spheroidal particle made up of smaller particles. They would all work to produce slow release, so why would the patentee have intended a limited meaning to his claims. The real point here is about “spheronising agent.” But the conclusion about “spheroid” is important to the argument about that.

We consider that the Judge was wrong to find that HPMC as used in the Cimex product was not a “spheronising agent” within the meaning of the claims.

The Judge recognised that the process of extrusion/spheronisation was only one of the ways in which a spheroid could be made. Other ways included rotor-granulation, a process which did not involve converting a cylinder into a sphere, but in which the spheroids are formed from a mass of powdered material.

Once the Judge had reached the correct conclusion that “spheroid” was not limited to the process by which the product was made, it was wrong for him to interpret “spheronising agent” narrowly so as to accept the argument of r/S (if indeed he did) that it only referred to non-water soluble materials (such as microcrystalline cellulose) which were incorporated to give the correct degree of plasticity in an extrusion/spheronisation process.

It is true that the specification deals expressly only with the extrusion-spheronisation process (see [43] and [51] quoted above), and that that explains the references to the non-water soluble spheronising agent (especially microcrystalline cellulose). But as the Judge correctly recognised other processes were not being excluded.

We also think he erred in excluding HPMC (as he did) on the alternative basis that the term was limited to agents which had assisted in making a sphere out of something that was not a sphere, and that the HPMC in the method used for the production of the Cimex product (active ingredient together with binder sprayed on to pre-manufactured sugar core) did not have that function.

The evidence was that a water soluble polymer such as HPMC was suitable for four out of the five spheronisation processes known at the priority date for producing spheroids for a controlled release formulation: (1) fluidised-bed granulation; (2) rotor granulation; (3) extended wet granulation; and (4) non-pareil beads (the Cimex process).

Accordingly HPMC fell within the definition in paragraph [42]

“The spheronising agent may be any pharmaceutically acceptable material that, together with the active ingredient, can be spheronised to form spheroids …”

In addition, even in the non-pareil beads method, where there is a pre-existing sphere, the HPMC assists in the formation of the relevant spheroids, i.e. those containing the active ingredient. We accept the submission by Mr Tappin that the core was not the spheroid of the claims. The spheroid is the sphere which comprises oxycodone and a spheronising agent. It is true that paragraph [44] draws a distinction between a spheronising agent and a binder, but in our judgment the fact that HPMC also acts as a binder or matrix does not prevent it from being a spheronising agent as that term is used in the specification and the claims.

So the Cimex product satisfies these aspects of claim 6 of 730 and claim 4 of 246.

The point here is whether, as r/S contend, claim 1 of 246 and claim 6 of 730 do not extend to a form of dosage in which some of the oxycodone is on the outside of the coating. This question arises because the Cimex product has an external layer on its spheroids consisting of about 20% of the drug, which is released immediately, the remaining 80% being within the coating which controls its release.

So far as claim 6 of 730 is concerned, the Judge had little difficulty in concluding that a tablet which otherwise infringed was not taken out of the claim by the addition of oxycodone on the surface of the spheroids. We agree. There is nothing in the language of claim 6 of 730 which excludes a tablet which has all the characteristics it sets out, but with the additional feature of an external application of oxycodone. There is also nothing in the teaching in the patent to suggest that such a tablet was intended to be excluded. Nor is there any commercial or technical reason for thinking that the patentee would have wanted to exclude an otherwise infringing article with such an additional feature.

Mr Silverleaf contended that claim 7, which is based on claim 6, indicates that such an article could not be within the ambit of claim 6, as it could not be within the ambit of claim 7. For the same reasons as apply to our construction of claim 1 of 246, as discussed in the immediately ensuing paragraphs, we do not consider the basis for that contention is well founded. However, even if a tablet with some of the oxycodone on the exterior of the coating were outside the ambit of claim 7, we are unconvinced that this would have resulted in claim 6 being similarly restricted. Claim 7 is, clearly and familiarly, intended to be more limited than claim 6, and it would therefore be unsurprising if its wording resulted in an implied limitation in addition to, indeed as a result of, an express limitation on the terms of claim 6.

That brings us to the question of whether such a tablet infringes claim 1 of 246. The Judge found this point difficult and so do we. However, we have come to the conclusion that claim 1 of 246 is infringed by a tablet which has oxycodone on the outside of the coating, provided that (i) the tablet contains, in addition, oxycodone which satisfies paras (a) to (c) of claim 1, and (ii) the tablet as a whole satisfies the dissolution requirements of para (d) of claim 1.

If claim 1 of 246 stopped at the end of para (c), it appears to us that the issue whether it covered a tablet, which conformed to the terms of paras (a) to (c) but had an additional application of oxycodone on the outside of the coating, would be relatively simple. The fact that such a tablet had an additional feature would no more prevent it infringing claim 1 of 246 than it would prevent it infringing claim 6 of 730. The tablet would be a “controlled release dosage form”, although it would also include dosage for immediate release.

Para (d) of the claim, however, presents two possible difficulties for this conclusion. First, as Mr Silverleaf pointed out, the dissolution rate would not be entirely attributable to the oxycodone described in the preceding three paragraphs: para (d) would be dissociated from paras (a) to (c). Secondly, it would mean that the “oxycodone salt” referred to in para (d) would not be precisely the same as the “oxycodone salt” referred to in paras (a) to (c). While these points are not without force, they do not persuade us that claim 1 of 246 should be restricted as r/S contend.

While it is true that para (d), on this reading, is, as it were, somewhat disconnected from paras (a) to (c) of the claim, such a disconnection is consistent with paras (b) and (c) referring expressly to the “said oxycodone salt”, tying them into para (a) where such a salt is mentioned, whereas para (d) is tied into the opening line of the claim, by virtue of its reference to the “said dosage form”. Accordingly, in the case of a tablet with externally applied oxycodone in addition to oxycodone within the coating, the “dosage form” is all the oxycodone, whereas the “said oxycodone salt” is that within the coating. Further, there is no logical, technical or commercial reason why the dissolution rates in para (d) should not extend to all the oxycodone in the case of a tablet with external oxycodone, as well as oxycodone within the coating.

The four references to “oxycodone salt” in para (d) might well be thought to apply to the oxycodone salt referred to in paras (a) to (c), and, of course, they do, even where there is also oxycodone outside the coating. In a case where there is oxycodone outside the coating, the question is whether they refer back to the oxycodone salt mentioned in para (a) or whether they are not so limited. In our view, they are not so limited. As a matter of ordinary language, there is no reason to construe them in such a limited way. Further, in paras (b) and (c), the references to oxycodone salt are prefixed by the word “said”, which plainly limits the expression to what is referred to in para (a), whereas the prefix is missing in the references in para (d), which therefore tends to suggest no such limitation.

In these circumstances, we think that the conclusion rightly reached by the Judge in relation claim 6 of 730 also applies to claim 1 of 246. In fairness to the Judge, it should be added that the argument before him appears to have proceeded primarily on the basis that, in the case of a tablet with oxycodone on the outside of the coating as well as within the coating, the 10 to 160 mg parameters in para (a) of claim 1 of 246 would apply to the total amount of oxycodone in the tablet, rather than, as we see it, the amount of oxycodone within the coating. This contention was put forward by Mr Tappin as his alternative case on this point; we think that it was rightly rejected by the Judge.

This issue of construction relates to integer 1(d) of claim 1 of 246. It requires the claimed dosage form to have “an in vitro dissolution rate, when measured by the USP Paddle method at 100 rpm in 900 ml aqueous buffer” of specified amounts. What does “measured by the USP Paddle method” mean?

The specification tells the reader at [15]: “USP Paddle Method is the Paddle Method described, e.g. in US Pharmacopoeia XXII (1990)”. One would obviously go to that. What one finds there is a description of a test “provided to determine compliance with the dissolution requirements where stated in the individual monograph for a tablet or capsule dosage form.” It is agreed that the patent, in specifying dissolution requirements, would be treated by the skilled person as the “individual monograph.”

The USP is effectively in two parts. First there is a detailed description of the apparatus to be used. A glass or other transparent vessel of specified dimensions is used with a water bath to keep constant temperature. A motor and a metallic drive shaft are provided. Two alternative stirring elements are described, one a “basket” and the other a “paddle”. It is not necessary to set out the fine detail of the apparatus. It is clear, and common ground, that integer 1(d) is calling for the paddle alternative, as specified in detail in the USP to be used. Moreover it is to be used under the conditions specified in the USP. The second part of the USP describes how the method is to be conducted and how one uses the method to determine drug release requirements.

The Judge accurately and uncontroversially summarised this relevant part of the USP:

[90] Section 711 is headed “Dissolution”. … It is sufficient to note that the reader is directed to place a single tablet in the apparatus, and to extract specimens of the solution at the specified time intervals. He is directed to perform the analysis as directed in the monograph and to repeat the test with “additional dosage forms”. Section 711 has an acceptance table with a series of staged tests, through which the experimenter has to proceed until the tests conform to the criterion. The number of dosage forms tested at each stage is 6.

[91] Section 724 is concerned with drug release requirements, and contains the appropriate alternative acceptance table for controlled release requirements when using the USP apparatus described in 711. Again there are three stages to the acceptance criteria. Level 1 requires the testing of 6 tablets: to pass at this level no individual value may fall outside each of the stated ranges. Level 2 requires a further 6 tablets to be tested and the average of 12 thus tested to be within the stated ranges. In addition, Level 2 imposes further requirements: none is to be more than 10% outside each of the stated ranges. Level 3 tests a further 12 tablets, averages all 24 and imposes further requirements still.

The issue between the parties is this: does the claim call for the whole of the test procedure in the USP, including the acceptance test, to be carried out so that the claim only covers that which passes the acceptance test, or is it sufficient if an individual dosage form passes the test? The point matters because only a modest (7%, nonetheless significant) proportion of the Cimex tablets have dissolution rates within integer 1(d). If the true construction of this feature requires compliance with the USP acceptance requirements there is no infringement, even though a proportion of the tablets, as individual tablets, do comply with the rates set out in the claim.

The Judge held that “measured by the USP paddle method” required only that an individual tablet had to have the specified rates of dissolution. The skilled person would read the claim as directed to the experimental procedure and apparatus specified in the USP. He reached that conclusion because the claim is to a “dosage form” not a whole batch of tablets. On the r/S construction one would have to test at least 6 tablets and possibly up to 24 tablets. And one could then decide whether the batch of tablets from which these were taken satisfy the criteria.

We think the Judge was right: the claim is for a dosage form. “When measured by the USP method” means the apparatus and method of its use described in the USP, not how that method is used to judge acceptance. It is a dosage form which must past the test.

Mr Silverleaf sought to avoid that construction because, necessarily, a single dosage form would be destroyed in testing it for infringement. He suggested it would be more rational to conclude that the skilled reader would be concerned with a batch, which is what the USP acceptance criteria are aimed at. We do not agree. If a single tablet is tested and is shown to be within the claim, it follows that the defendant has infringed. If some of his tablets are outside the claim, experiments can clearly be run to estimate the scale of infringement. Moreover, Mr Silverleaf’s construction also involves destruction of tablets – and perhaps quite a lot of them. So the destruction point is essentially neutral.

We say that not only for the Judge’s reason, but also from the following consideration. If the claim really had in mind passing the acceptance criteria, one would have expected the examples to go into that detail, showing the results for measuring the individual tablets and how the acceptance criteria of the USP were satisfied.

For example at [84] the patent says “Next dissolution studies were conducted on the tablets of Examples 7-12 using the USP basket method as described in US Pharmacopoeia XXII (1990)”. Details of the speed, medium and temperature are specified. In the following table, time and % of oxycodone dissolved are set out for each type of tablet. There is not a hint that the acceptance criteria have come into it. Mr Silverleaf suggests that they were nonetheless used, and that the figures given are averages of the tablets tested. He places some reliance on the fact that the plural “tablets” is used.

We cannot agree. It is quite improbable that the table would have been presented as it is if the patentee was seeking to inform his reader that the USP acceptance criteria were satisfied.

Moreover at [13] the patent speaks of the amount of oxycodone released when measured by the USP Paddle Method. It adds “the amounts released being, in all cases, a mean of at least three experiments.” It would be almost perverse to read that as referring to anything other than an experiment repeated three times over using a tablet at a time. What “three experiments” could be meant if Mr Silverleaf were right? The acceptance criteria test produces a binary conclusion, yes or no. You cannot average three such conclusions.

Mr Silverleaf also placed reliance on the fact that integer 1(d) required testing at a pH between 1.6 and 7.2. The dissolution rate must be satisfied for that range of pH. He said you can only test over a range by testing more than one tablet. So the claim cannot really be to a single tablet. We do not agree. pH independence can be established by testing a number of tablets (and it was) but once you have done that you have established the position for that pH. Moreover Mr Silverleaf’s construction also involves destruction of tablets – just more than are needed on Napp’s construction. So the point is essentially neutral. It is a long way from showing that the claim would be understood by the skilled man as requiring that the acceptance criteria of the USP must be met.

Accordingly we think the Judge was correct on this point and that the Cimex tablets satisfy requirement 1(d) of the claim.

The position as regards the German equivalents of the patents in suit is a little complicated and still provisional. As regards infringement, on 27^th August 2007 Napp were refused an interim injunction by the Landgericht in Dusseldorf (Judges Grabinski, Klepsch and Thelen). An appeal was withdrawn when the Oberlandesgericht indicated it needed an expert. A final decision holding non-infringement was reached by the Landgericht in Mannheim on August 2008 (Judges Kircher, Lehmeyer and Lembach). An appeal from that decision is pending. As regards validity, the German counterpart of 246 is under attack in the Federal Patent Court. 730 is currently under central attack in an EPO opposition. The German version of that patent is not under separate attack in Germany, it being the practice there to wait until an EPO opposition is concluded before allowing such an attack.

We differ from the conclusions reached by the Dusseldorf and Mannheim courts on construction. We should briefly say why.

As regards the Dusseldorf decision it appears to have overlooked the fact that claim 1 of 246 is not limited to the four elements (a) to (d). It opens with the words “comprising”, which does not mean “only consisting of”. It led to the conclusion that the dissolution profile (d) had to be the result of the presence of the three elements, whereas it is the formulation as whole which is to have the prescribed profile. The Dusseldorf court also seems to have taken the view on the facts that controlled release could not be obtained because of the presence of the “outer” oxycodone. But on the findings of fact here, 80% of the oxycodone is slow released.

As regards the Mannheim decision, the claim of 730 is rather different from that we have considered – the Court worked on the claim as allowed by the Opposition Division of the EPO (a decision itself under appeal). That claim refers to the “total dosage” in the “dosage form”. The reasoning is then carried over into construction of 246.

We are not persuaded by either of these decisions, even though we give great respect to the decisions of the German courts.

Mr Silverleaf submits that both patents are invalid in a variety of ways by reason of the objection which goes by the jargon “added matter.”

The fundamental provision is Art 123(2) of the EPC:

(2)

A European patent application or a European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed.

This has been implemented here in the cack-handed way described in more detail in Vector v Glatt [2007] EWCA Civ 805, [2008] RPC 243. Since our provisions mean the same as Art 123(2) there is no point in referring to them.

It was rightly common ground that this rule applies as much to an amendment made as the consequence of the patentee making a divisional application as for any other amendment made to a patent or patent application.

The leading authority in the EPO is that of the Enlarged Board of Appeal in Case G1/93 Advanced Semiconductor Products. In our courts we apply the principles laid down there, which coincide with the principles already laid down here by Aldous J in the Bonzel case. Jacob LJ summarised the position in Vector v Glatt, starting with a citation in [3] from his judgment in Merrell Dow v Norton (unreported):

[3] ……However, there is a more general principle stated by Aldous J in Bonzel v Intervention (No 3) [1991] RPC 553 at 574. He stated the test for examining whether amendment involved the adding of subject matter to be as follows:

(1)

To ascertain through the eyes of the skilled addressee what is disclosed, both explicitly and implicitly in the application.

(2)

To do the same in respect of the patent as granted.

(3)

To compare the two disclosures and decide whether any subject matter relevant to the invention has been added whether by deletion or addition. The comparison is strict in the sense that subject matter will be added unless such matter is clearly and unambiguously disclosed in the application either explicitly or implicitly.”

[4] In Richardson-Vicks’ Patent [1995] RPC 568 at 576 I summarised the rule in a single sentence:

“I think the test of added matter is whether a skilled man would, upon looking at the amended specification, learn anything about the invention which he could not learn from the unamended specification.”

I went on to quote Aldous J in Bonzel. His formulation is helpful and has stood the test of time.

[4] The reason for the rule was explained by the Enlarged Board of Appeal of the EPO in G1/93 ADVANCED SEMICONDUCTOR PRODUCTS/Limiting feature [1995] EPOR 97 at [Reasons 9]:

“With regard to Article 123(2) EPC, the underlying idea is clearly that an applicant shall not be allowed to improve his position by adding subject-matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying upon the content of the original application.”

[6] Mr Richard Arnold QC provided a clear articulation as to how the legal security of third parties would be affected if this were not the rule:

The applicant or patentee could gain an unwarranted advantage in two ways if subject-matter could be added: first, he could circumvent the “first-to-file” rule, namely that the first person to apply to patent an invention is entitled to the resulting patent; and secondly, he could gain a different monopoly to that which the originally filed subject-matter justified.

[7] Kitchin J has recently helpfully elaborated upon the Bonzel formulation in European Central Bank v Document Security Systems [2007] EWHC 600 (Pat), 26^th March 2007:

[97] A number of points emerge from this formulation which have a particular bearing on the present case and merit a little elaboration. First, it requires the court to construe both the original application and specification to determine what they disclose. For this purpose the claims form part of the disclosure (s.130(3) of the Act), though clearly not everything which falls within the scope of the claims is necessarily disclosed.

[98] Second, it is the court which must carry out the exercise and it must do so through the eyes of the skilled addressee. Such a person will approach the documents with the benefit of the common general knowledge.

[99] Third, the two disclosures must be compared to see whether any subject matter relevant to the invention has been added. This comparison is a strict one. Subject matter will be added unless it is clearly and unambiguously disclosed in the application as filed.

[100] Fourth, it is appropriate to consider what has been disclosed both expressly and implicitly. Thus the addition of a reference to that which the skilled person would take for granted does not matter: DSM NV’s Patent [2001] R.P.C. 25 at [195]-[202]. On the other hand, it is to be emphasised that this is not an obviousness test. A patentee is not permitted to add matter by amendment which would have been obvious to the skilled person from the application.

[101] Fifth, the issue is whether subject matter relevant to the invention has been added. In case G1/93, Advanced Semiconductor Products, the Enlarged Board of Appeal of the EPO stated (at paragraph [9] of its reasons) that the idea underlying Art. 123(2) is that that an applicant should not be allowed to improve his position by adding subject matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying on the content of the original application. At paragraph [16] it explained that whether an added feature which limits the scope of protection is contrary to Art 123(2) must be determined from all the circumstances. If it provides a technical contribution to the subject matter of the claimed invention then it would give an unwarranted advantage to the patentee. If, on the other hand, the feature merely excludes protection for part of the subject matter of the claimed invention as covered by the application as filed, the adding of such a feature cannot reasonably be considered to give any unwarranted advantage to the applicant. Nor does it adversely affect the interests of third parties.

[102] Sixth, it is important to avoid hindsight. Care must be taken to consider the disclosure of the application through the eyes of a skilled person who has not seen the amended specification and consequently does not know what he is looking for. This is particularly important where the subject matter is said to be implicitly disclosed in the original specification.

[8] When amendment of a granted patent is being considered, the comparison to be made is between the application for the patent, as opposed to the granted patent, and the proposed amendment (see the definition of “additional matter” in s.76(1)(b)). It follows that by and large the form of the granted patent itself does not come into the comparison. ….

[9] A particular, and sometimes subtle, form of extended subject matter (what our Act calls “additional matter”) is what goes by the jargon term “intermediate generalisation”. Pumfrey J described this in Palmaz’s European Patents [1999] RPC 47, 71 as follows:

“If the specification discloses distinct sub-classes of the overall inventive concept, then it should be possible to amend down to one or other of those sub-classes, whether or not they are presented as inventively distinct in the specification before amendment. The difficulty comes when it is sought to take features which are only disclosed in a particular context and which are not disclosed as having any inventive significance and introduce them into the claim deprived of that context. This is a process sometimes called ‘intermediate generalisation.”

Mr Silverleaf contended that there was a further, special, rule of law where the amendment consisted of what is called “an undisclosed disclaimer.” He submitted this was laid down by the Enlarged Board in Case G1/03 PPG Industries.

We must briefly explain the problem addressed in that case. During the course of prosecution a piece of prior (actual or, in the case of a co-pending application, deemed) art may emerge which destroys the novelty of part of what was sought to be claimed. A basic question arises: can the patentee amend what he claims so as to cut out the anticipatory material? To cut it out he needs to identify it so it can be disclaimed. His original application will have made no reference to it. So by referring to it and disclaiming something he has never referred to before (hence the phrase “undisclosed disclaimer”) the patentee is adding “subject-matter which extends beyond the content of the application as filed.”

If one stands back one can see that by making an undisclosed disclaimer a patentee might be adding subject matter. For instance suppose he originally described and claimed a process to be carried out at a temperature range of from 0⁰ – 100⁰C. He discovers later that it only works at between 75⁰ and 80⁰C. If he were allowed to amend the description and claim to that narrow range (never mentioned before) he would in practice be adding after acquired knowledge to render his patent sufficient.

On the other hand such an amendment would not be adding anything new where the disclaimed range was simply that disclosed in a co-pending application.

G1/03 gave guidance on how the problem of the potential wrongful addition of matter should be dealt with in certain cases. Specifically it considered the cases of deemed prior art in an earlier co-pending application, an accidental anticipation and deletion of matter unpatentable because it was non-technical. It did not consider disclaimers in the context of divisionals, but Mr Silverleaf suggests that its reasoning applies to these too.

The headnote – which is accurate - reads:

I. An amendment to a claim by the introduction of a disclaimer may not be refused under Article 123(2) EPC for the sole reason that neither the disclaimer nor the subject-matter excluded by it from the scope of the claim have a basis in the application as filed.

II. The following criteria are to be applied for assessing the allowability of a disclaimer which is not disclosed in the application as filed:

II.1 A disclaimer may be allowable in order to:

- restore novelty by delimiting a claim against state of the art under Article 54(3) and (4) EPC;

- restore novelty by delimiting a claim against an accidental anticipation under Article 54(2) EPC; an anticipation is accidental if it is so unrelated to and remote from the claimed invention that the person skilled in the art would never have taken it into consideration when making the invention; and

- disclaim subject-matter which, under Articles 52 to 57 EPC, is excluded from patentability for non-technical reasons.

II.2 A disclaimer should not remove more than is necessary either to restore novelty or to disclaim subject-matter excluded from patentability for non-technical reasons.

II.3 A disclaimer which is or becomes relevant for the assessment of inventive step or sufficiency of disclosure adds subject-matter contrary to Article 123(2) EPC.

Mr Silverleaf particularly relied on paragraph 2.6 of G1/03 which is headed “Disclaimers making a technical contribution.” At the heart of his submissions was the suggestion that somehow the Board was constructing an extra rule about disclaimers. We do not accept that. The key to the reasoning is at the end of 2.6.1

Only the approach restricting disclaimers to limitations not contributing to the invention and thereby taking the decisive criterion from Article 123(2) EPC rather than from Article 56 EPC complies with the Convention.

This amounts to saying that the key question in every case is the Art 123(2) question. There is no additional criterion, only a question as to how that is to be applied in the case of disclaimers.

Mr Silverleaf suggested more was somehow implied from an earlier sentence in the same paragraph:

Rather, in the first place, the accidental character of the anticipation has to be ascertained. If this requirement has been accepted, the allowability of the disclaimer may be called into question, if it becomes apparent that the limitation is relevant for assessing inventive step or sufficiency of disclosure.

We do not agree. What the Board was saying here was that if it is the later added disclaimer which renders the patent non-obvious or sufficient, there may be (“called into question”) an added teaching. And so there may – it depends on whether that is so in fact.

The key point is also apparent in the next sentence where the Enlarged Board helpfully used the phrase “mere disclaimer.”

2.6.2

The principle that an undisclosed limitation has to be a mere disclaimer in the above sense to be allowable, also provides the solution in the case where there are two anticipations, one piece of prior art under Article 54(3) as well as another one under Article 54(2) EPC.

The Board goes on to consider undisclosed disclaimers formulated to meet prior art more generally. It is unnecessary here to cite that and we can go to paragraph 2.6.5:

2.6.5

It results from the foregoing that a disclaimer may serve exclusively the purpose for which it is intended and nothing more. In the case of a disclaimer concerning conflicting applications, its purpose is to establish novelty with respect to a prior application in the sense of Article 54(3) EPC. In the case of a disclaimer concerning state of the art under Article 54(2) EPC, its purpose is to establish novelty vis-à-vis an accidental anticipation as defined in this decision. Finally, a disclaimer excluding subject-matter not eligible for patent protection may only serve the purpose of removing such specific legal obstacle. If a disclaimer has effects which go beyond its purpose as stated above, it is or becomes inadmissible.

That G1/03 does not set up any further or more extensive rule than the basic rule that an undisclosed disclaimer is permissible as not adding matter provided it is a “mere disclaimer” is confirmed by a later ruling of an EPO Board of Appeal in T1139/00 Cordis Corpn. The main request of the patentee included a disclaimer. There was argument about the scope of G1/03 The TBA said:

2.3

It follows both from the questions put to the Enlarged Board as well as from the Order of G 1/03 that this decision concerns only the situation where the subject-matter excluded from the scope of a claim did not have a basis in the application as filed. ….

2.5

In the present case, by contrast [to an undisclosed disclaimer], the subject-matter excluded by the disclaimer is supported by the application as filed. …

2.6

Moreover, G 1/03 confined itself to the consideration of those cases where a disclaimer is employed in order to restore novelty in cases where documents under Article 54(3) and 54(4) are revealed after the application date, or to disclaim subject-matter excluded from patentability for non-technical reasons. G 1/03 did not consider the case of conflicting applications having the same applicant and the same application date, e.g. the case of parent and divisional applications. For these reasons the Board is of the opinion that the conclusions of G 1/03 do not apply to the present case.

So this TBA has held that G 1/03 is confined to novelty restoring or exclusion of unpatentable subject-matter disclaimers. It went on, so rightly in our view, to address the real question: was there added subject matter?

3

The present Board has based its decision as to the allowability of the "disclaimers" in the present case on the basis of whether the patent proprietor gains an unwarranted advantage by its use, whether the use of a "disclaimer" could be damaging to the legal security of third parties, and whether it provides a technical contribution to the subject-matter of the claimed invention.

These are important considerations since the present decision must be compatible with G 1/93 (OJ 1994, 541), which is referred to in G 1/03. The latter decision places considerable importance on whether a disclaimer changes the technical content of an application (see Reasons 2. third paragraph, 2.1.3 second paragraph, 2.2.2 last sentence of the last paragraph, and 2.4.1 penultimate sentence), or whether it affects the question of inventive step or sufficiency of the disclosure (points 2.5.2 and 2.5.3 of the Reasons). The same constraints must apply in the present case, even though this does not fall within the scope of G 1/03.

As set out in G 1/93, an applicant may not gain an unwarranted advantage by an amendment, and so damage the legal security of third parties (point 9 of the reasons). G 1/93 considers that the main purpose of Article 123(2) EPC is to create a fair balance between the interests of applicants and patentees, on the one hand, and competitors and third parties, on the other hand (point 8. of the Reasons). It then concludes that

"A feature which has not been disclosed in the application as filed but which has been added to the application during examination and which, without providing a technical contribution to the subject-matter of the claimed invention, merely limits the protection conferred by the patent as granted by excluding protection for part of the subject-matter of the claimed invention as covered by the application as filed, is not to be considered as subject-matter which extends beyond the content of the application as filed within the meaning of Article 123(2) EPC. The ground for opposition under Article 100(c) EPC therefore does not prejudice the maintenance of a European patent which includes such a feature" (point 2. of the Order).

Finally on the facts it concluded:

3.1

The only effect of the introduction of the disclaimers in the present case is to remove one embodiment from the scope of protection without providing any technical contribution to the invention as claimed.

Floyd J was entirely right when he said:

[122] Nevertheless, the test for added subject matter remains that set out in the Convention and the Act. The reason that disclaimers of accidental and deemed anticipations do not offend is that they do not add subject matter relevant to the invention. If a disclaimer introduced by a divisional application does not add subject matter relevant to the invention, but merely excludes subject matter from protection, then it too will not offend against the provision.

What must be shown is that subject-matter relevant to the invention has been added from the application to the patent under attack. The inquiry is as between the application as filed and that patent.

The application as filed was PCT No. WO 93/10765. The differences said to add subject-matter to 730 are essentially in a single passage. We set it out here.

The present matrix may be any matrix that affords in vitro dissolution rates of oxycodone within the narrow ranges required and that releases the oxycodone in a pH independent manner except an acrylic resin matrix being selected so that the formulation provides pH-independent dissolution characteristics. (p.9 of the PCT with strikethrough showing deletion and italics showing addition as in [33] of 730).

Three other differences should be noted. First a passage on p.11 of the application a passage about “one preferred embodiment” which refers to the use of an acrylic resin and a particularly preferred such resin called Eudragit RS PM does not appear in 730. Secondly, again speaking of the preferred dosage form, a reference to “acrylic resin” is deleted.

Thirdly, and importantly, 730 says this at [7]:

Granted EP 0576 643 based on European application no. 92 925 406.8 from which the instant application is a divisional, forms the basis of the disclaimer in the attached independent claim 1.

The disclaimer in claim 1 reads “other than an acrylic resin matrix selected so that the formulation provides pH independent dissolution characteristics”, i.e. it corresponds to the italicised “new” matter in the key passage. And if one goes to ‘643 one finds, as one would expect, that the matter disclaimed in 730 is in its claims all of which include the limitation “said acrylic resin matrix being selected so that the formulation provides pH-independent dissolution characteristics.”

Mr Silverleaf submits that there is indeed added-matter. The process of division has created, he submits, a disclosure of two alternative classes of acrylic resin which can be used to produce an overall pH-independent formulation - an acrylic resin which is itself pH-independent and one which is not. It would be all right to divide out these two classes if they were separately disclosed in the application, but they are not.

Moreover, he submitted, Napp’s expert, Professor Aulton, by implication acknowledged there was added matter. For when the Professor was advancing a point of difference from Oshlack he pointed out that there was “no reason to modify Oshlack’s formulation either to remove the aliphatic alcohol/acrylic combination (…) or to choose pH-dependent behaviour. So, submitted Mr Silverleaf, the “added matter” was relied upon as a point of difference.

He further submitted that the position cannot be saved because the application contains specific examples which do show the use of both pH-dependent and pH-independent resins (judgment at [128]). That would be, he said, an illegitimate intermediate generalisation from the examples to the classes.

There was some debate about precisely what the disclaimed matter in the italics meant – did it mean all acrylic matrices or only those which would produce a pH-independent formulation. We rather think it must be the latter – so the passage is not read as though there were a comma after “acrylic matrix” but in the end it does not matter.

For we do not accept that there is a disclosure in 730 of two classes of pH-independent acrylic resins. Both in the application and the patent the pH-independence is that of the formulation, not the resin as such. The Judge put it concisely and accurately:

[128] In my judgment the skilled person would read 730 as teaching that acrylic resins were suitable materials to use for achieving pH-independent release, but that the combined effect of [0007] and the disclaimer was that these materials were not claimed. I do not think that he would derive from the general disclosure any technical teaching about pH-dependent acrylic resins.

As to the point based on Professor Aulton’s evidence, we do not read that evidence as saying anything about whether there is a new teaching in 730. As an expert witness the Professor is simply saying there is no motive to make the changes from Oshlack to come within the claim. That does not show there is added matter at all.

In the end, although it took some time to argue, this point turned out to be no more than an ingenious attempt to construct additional subject-matter when none was really there. It is noteworthy that no expert suggested he would learn anything new from 730 which he could not learn from the application.

It follows that Napp’s proposal to amend to cure the added matter defect, should there be one, is unnecessary. We say no more about it.

We can deal with this quite shortly. The added subject-matter is said to be contained in claim 6. Mr Silverleaf put it this way:

We say that if that claim covers water soluble spheronising agents, it must also disclose the possibility of using them or it does not actually read on to them at all; because otherwise the teaching of the document is to use water insoluble ones. We say if in fact the claim is wide enough to cover water soluble spheronising agents, there must be added matter.

The trouble with that submission is that claim 6 does not mention – so cannot possibly teach – water soluble spheronising agents. It just specifies “a spheronising agent.” The fallacy in the argument is to equate disclosure of subject matter with scope of claim, a fallacy struck down as long ago as 1991 in AC Edwards v Acme Signs & Displays [1992] RPC 131 (see e.g. per Fox LJ at p.143).

Before the Judge three obviousness attacks were run, obviousness by reason of common general knowledge, obviousness from a prior patent called Oshlack (published in January 1988 – just under 3 years before the priority date of the patents concerned) and obviousness from a patent called Goldie. All three attacks failed. On appeal only the Oshlack attack is pursued. Because the inventive concept of both patents, at the level of generality which both sides accepted was appropriate, the attack is the same for each patent. So they stand or fall together.

In dealing with obviousness the Judge used the well established Windsurfer/Pozzoli structured test which we need not set out again here. Mr Silverleaf does not make any complaint of that. He suggests, as he must, that the Judge made an error of principle – for an appeal court will not “undertake a de novo evaluation of the facts” (per Lord Hoffmann in Biogen v Medeva [1997] RPC 1 at p. 24) and must be “very cautious in differing from the judge’s evaluation” (ibid.).

Before coming to the suggested error, it is important in our judgment to understand how the Judge reached his now unchallenged view that neither patent was invalid over common general knowledge. He found that:

[204] Given that this document post-dates the priority date, I think it is powerful evidence that before the priority date oxycodone was generally perceived as a weak opioid analgesic. Moreover it is strong support for the fact that relatively little was known about it as a single entity oral dosage form in 1991.

[205] I conclude that the majority of those clinicians who had experience of oxycodone would regard it as a co-drug administered with aspirin or paracetamol to give additional analgesia by another mechanism. They would know that it was a potent opioid. I consider that most clinicians would have no practical experience of the use of oxycodone as an opioid alternative to morphine in 1991. Such use did not form part of the common general knowledge.

Moreover he was persuaded by the overall effect of the evidence that his initial provisional view (that it was uninventive to propose a controlled release version of known drug) was wrong. Most importantly he specifically rejected Professor McQuay’s evidence that oxycodone would make a shortlist of known drugs as suitable alternatives for controlled release morphine.

That to our mind is a crucial finding. Coupled with the finding that oxycodone was not known as anything other than a co-drug and was not perceived as an alternative to morphine, the case on common general knowledge had to fail. So can Oshlack make a difference?

The Judge said, in a passage unchallenged on appeal:

[237] Oshlack is a document aimed at a formulator. Its disclosure is concerned far more with the novel controlled release matrix than with the identity of the drugs released by it. In that respect it is different to the patent in suit which includes information about the clinical performance of the drug. I gained the very clear impression that it was not the sort of document which any of the clinicians who gave evidence would be accustomed to reading or which would much influence their thinking. Nor do I think it is a document which would influence the thinking of a pharmacologist.

It is not a particularly promising start for an obviousness attack. For r/S’s own expert witness, Professor Davis, fairly said: “in my view the formulator in November 1991 would regard [Oshlack] as a rather unexciting document”.

What Oshlack is about is the use of a higher aliphatic alcohol (hydrophobic) and an acrylic resin (hydrophilic) for the matrix of a controlled release formulation. Professor Davis was not impressed by the idea:

The idea of making a controlled release matrix using a mixture of a hydrophobic and a hydrophilic polymer would have been part of his common general knowledge. Combining a higher aliphatic alcohol (hydrophobic) and an acrylic resin (hydrophilic) would not have been thought of as a major advance. Both classes of material had long been used in controlled release formulations and the reference to “potentiation” in the context of examples 2 and 3 is not supported by the data. Furthermore, the formulator would know as a matter of his common general knowledge that two of the example drugs in 104A were already on the market in a controlled release dosage form, namely propanolol hydrochloride (example 3, sold under the name Inderal) and morphine sulphate (example 4, sold under the name MST Continus). 104A does not contain any data comparing the performance of these commercial products with the formulations of the invention.

In his “summary of the invention” Oshlack does not mention oxycodone – or any other drug: he presents his invention as a resin for the slow release of any drug. He is not concerned with the particular drug the release of which is to be controlled. His specific examples are to several drugs, aminophylline, oxycodone, propranolol and morphine. It is particularly noteworthy that he does not say that a slow release oxycodone can be a substitute for slow-release morphine, still less that it has advantages over it. All he says about oxycodone is that it is a “narcotic analgesic”, whereas in relation to morphine he says: “the narcotic drug Morphine is very effective for pain relief, and in the care of terminal cancer, a controlled release tablet, releasing the morphine slowly ever many hours is particularly suitable.”

The Judge accurately set out the difference between the disclosure of Oshlack and the inventive concept of the patents in suit as he found it to be (at [160]) namely 12 hourly controlled release formulation of oxycodone:

[235] As compared with the enabled disclosure of Oshlack, the differences with the inventive concepts of the various claims in issue would appear to be that each claim relied on requires at least one of the following features:

i)

the provision at steady state after 12 hourly dosing of maximum and minimum plasma concentrations within ranges;

ii)

a film coated spheroid formulation;

iii)

an in vitro release rate by USP Paddle Method (still releasing after 4 hours);

iv)

a coating controlling release.

The Judge held that a skilled person would have gone as far as trying to carry out the oxycodone example to test Oshlack’s hypothesis that an aliphatic alcohol can be used in place of a polymer. We are not sure ourselves that we would have gone even that far, but we are certainly not prepared to say that conclusion was not open to him.

The Judge went on to hold that the example is not within the claim – not least because the release would be much too fast (4 hours, judgment [230]). However the Judge was not prepared to go any further with r/S’s contentions. He rejected the idea that having tried thus far, and found that 12 hour slow release was not achieved, that the skilled person would have set about modifying Oshlack so as to achieve 12-hour slow release. That seems to us well within the permissible range of value judgments open to him. Unless there was a point in pressing on, why should the skilled person embark on what would be a somewhat troublesome, even if uninventive development programme? The answer is the same as for the case on common general knowledge – there was no point.

Mr Silverleaf submitted that he had an alternative case, one that he put in his reply speech to the Judge but which did not reach specific consideration by the Judge. We are not convinced that it really is an alternative case. This is what it is, as expressed in a post-oral argument submission to us:

“Once one has Oshlack as the starting point in this case, the position is different. Oshlack presents a controlled release formulation of oxycodone. On the figures presented in example 2B it appears suitable for administration at 12 hourly intervals. As a matter of fact, we know that when made up it releases more quickly so that it requires modification to provide a release rate actually so suitable.

Having been presented by Oshlack with the concept of a controlled release formulation of oxycodone, the clinical issue (whether there is any purpose in making up such a formulation) disappears. The problem has ceased to be a clinical one and become purely a formulation issue. In terms of problem and solution, the problem is no longer ‘can you find an alternative to morphine’ (the clinical question) but ‘can you make up a formulation of oxycodone suitable for 12 hourly administration given the teaching of Oshlack’ (a pure formulation question). That is why the clinician’s motivation, crucial to assessing obviousness over common general knowledge, is irrelevant when considering obviousness over Oshlack.

We know that the formulator, if asked the second question, would say “yes” without the need for experimentation because the judge has found in paragraph 242 of his judgment that he could predict with reasonable certainty that he could so. Therefore, in terms of problem and solution, the solution is obvious. The difference from obviousness over common general knowledge is that Oshlack asks the formulator the question and the formulator’s expertise gives you the answer. There is no need for a motivation to make up the formulation because its properties are predictable from the formulator’s general knowledge. Obviousness over common general knowledge requires the clinician to ask the formulator the question and, on the facts, that would not happen so the answer would never be sought. That is why motivation is central to that approach to the case, but irrelevant to the case over Oshlack.”

We do not accept that argument. It makes no sense to say that a formulator would press on and develop a 12-hour release formulation without any apparent clinical point. Motive remains relevant on any view. Moreover, for the reasons identified by Mr Tappin in his response, it is not correct to say that Oshlack example IIB even apparently shows a 12-hour release product.

We should also mention the argument briefly advanced by Mr Silverleaf in his oral submissions. He submitted that this was a case of an “unexpected advantage” of the sort found not to save a patent from an obviousness attack in Hallen v Brabantia [1991] RPC 195. There the prior art disclosed a type of corkscrew to which PTFE (the well-known non-stick plastic) had been applied to make it easier to penetrate the cork. It was obvious that the same advantage would apply to all corkscrews. What was not foreseeable was that there was an extra advantage for a “self-puller” type of corkscrew. But a PTFE coated self-puller was obvious nonetheless.

There is a real difference between that sort of case and this. There it was obvious to put PTFE on any corkscrew and that a worthwhile advantage would be obtained. Here it was not obvious that any advantage would be obtained, for there was no demand for an oral, still less a 12-hour (or any) slow release, formulation of oxycodone. An unexpected advantage only fails to defeat an obviousness attack where there is a real motive to use the idea apart from that advantage. For only then will the skilled man more or less inevitably bump into the unexpected advantage. And even that may not be enough to destroy a patent – for there may be room in some cases (we express no opinion) for an invention by selection.

Given our conclusions, it is unnecessary to discuss Mr Tappin’s fall-back arguments about later claims or the question of amendment of patent.

We dismiss r/S’s appeal concerning validity and allow Napp’s appeal concerning infringement. The patents are valid and infringed. Although we differ from the Judge on just two of the many points argued before him, we would like to pay tribute to his meticulous and careful judgment.