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Scottish Polymorphs
Arrow, Norton, and Organon
On September 15th, Lord Glennie gave judgment in a case before the Scottish Court of Sessions relating to patents concerning tibolone[1]. Arrow and Norton sought to revoke patents relating to high crystalline purity and high chemical purity of a single polymorph form of tibolone. The first point to note was that this action took place in Scotland. It may surprise some of you, perhaps especially those who are not British, that Scotland represents a separate jurisdiction for patent matters (and indeed for other matters) and that different legal systems apply in Scotland and England. The 1977 Patents Act of course applies, in the same way that it does in the rest of the UK, but the Scottish courts which determine whether there is validity or infringement have their own distinct legal origins and procedures.
In recent years, a few IP cases have been instigated before the Scottish courts, and this has tactical and strategic implications. Very simply put, some litigants have concluded that the Scottish courts, having less experience of IP cases, and fewer specialist lawyers, might be a “softer touch” than the Patents’ Court with its specialized judges. And, in some cases, the more convoluted procedures of the Scottish courts can work to the advantage of wealthier, stronger parties. One advantage for the party initiating litigation, is that, because of the small size of the Scottish bar, it can effectively almost monopolise counsel through retaining those with most experience before the other party has any idea that it is to be involved in Scottish proceedings. Some generic companies have considered not launching their products in Scotland at least initially, lest they become the subject of litigation in an unfamiliar jurisdiction.
The jurisdictional issues highlighted by this case are all the more interesting in the light of an earlier judgment of the English Patents Court relating to another tibolone polymorph patent, IVAX v Akzo , and given challenges to tibolone patents before the EPO. Whatever the experience of Scottish courts, this latest judgement is comprehensive, and in favour of the generic companies, and may contradict the idea that Scottish courts are more likely to determine matters in favour of the R & D industry.
Norton sought to revoke Akzo’s patent no 1121375, claiming tibolone of high chemical purity, which was licensed to Organon. Arrow joined the proceedings, also seeking to revoke patent number 0389035, claiming tibolone of high crystalline purity. Arrow and Norton sought revocation of certain claims in both patents on the basis that these were not novel (anticipated), obvious, and insufficient.
‘035
035 claimed a pure crystalline form of tibolone. Tibolone had been known since the 1960s, and sold under the trademark “Livial” since the 1980s. The ‘035 patent related to a single polymorph, Form 1, the monoclinic P21 Form and claimed products containing less than 10% of the triclinic Form 2. Form 1 of Tibolone is more stable, has a better shelf life and is more reproducible and the patent discusses the crystallization process, and the differentiation between Forms I and II and the advantages of Form I.
It was accepted that a paper by Declercq and van Meersche (‘Declercq’) disclosed the monoclinic form. Akzo argued that at the time of the Declercq paper the polymorphism of tibolone had not been discovered, and that the Form disclosed by the Declercq paper could not therefore be called Form I, just as the first Queen Elizabeth could not be called Elizabeth I until there was a second queen, also called Elizabeth. The judge said not – the first Queen Elizabeth was still Elizabeth I, before the existence of the second Queen with the same name. The claims which Arrow and Norton sought to invoke were product claims, and it did not matter that the Declercq paper did not show their method of manufacture, nor that the product which was the subject of the Declercq paper may well have contained the Form II polymorph as well. It was sufficient that the single crystal disclosed was that of Form 1. This satisfied the criteria established in Merrell Dow and an attack based on anticipation succeeded – the product had been disclosed even if that method of manufacture given by Declercq did not inevitably or even usually lead to the production of Form 1.
In relation to obviousness, the judge stated that the man in the art, whilst unimaginative, is not uninterested in accomplishing results. The judge accepted that the existence of polymorphs was well known to process research chemists in pharmaceuticals in the late 1980s – he would have known that most steroids had polymorphs, with different melting points, different stability, etc., but the judge felt that the acknowledgment of polymorphism did not point to the discovery of the polymorph in this particular case – without knowing that a polymorph of tibolone existed it was not obvious to develop it. I would have liked this aspect of the judgement spelt out more – if the existence of polymorphs, each with their own particular qualities was well-known, why was it not obvious to identify and choose the preferred polymorph in this particular case?
‘375
‘375 relates to a product of high chemical purity. The object of the invention was stated to be to enhance shelf-life, and the discovery underlying the invention was the reduction in the level of a certain impurity if crystals were allowed to age. Claims 1-3 of ‘375 were worded as product claims relating to product of a particular purity. Claim 4-6 related to the crystal ageing step and the production of a purer product where there was delay before drying. It was argued that claims 4-6 represented a new step in the process of making an old product and the fact that a new step existed should not stop the use of other methods. There were other known ways of preparing pure tibolone – recrystallization is basic chemistry, and there was no basis for the product claims per se. The product claims did not refer to the aging process as a specific feature, and if this had been intended, then the claims were insufficient. Whilst the patent might have been directed at the production of bulk product, claims 1-3 did not need to be read that way – the purity claimed was achievable by conventional methods within common general knowledge and it was an accepted argument that a document disclosing a compound and its manufacture makes it available to the public in all grades of purity that are achievable by conventional methods. This is the teaching of European patent office decisions and should be followed.
What useful conclusions can we draw from this case? The finding of fact that the existence of polymorphs was within the public domain in the 1980s seems convincing to me, (and accords with the views of the Patents Court in IVAX v Akzo) as does the argument that if the existence of a product and its method of manufacture are disclosed, then the disclosure will encompass all grades of purity that are achievable by conventional methods. It seems reasonable to me that product claims for polymorphs of known products in patents of this generation should be regarded as obvious, but there still is scope for process claims on polymorphs – not all methods of manufacture will necessarily include an enabling disclosure of the method of manufacture of the particular polymorph. I am intrigued by the reference to the Scottish court. Perhaps the decision by Lord Glennie will lead to fewer referrals to Scottish courts in future. I would love to hear of your experiences.
If you would like to know more about this case, more about the validity of patents on polymorphs, or any of the matters referred to, or would like advice on novelty, obviousness or insufficiency, please contact me.
Footnotes:
[1] Arrow Generics Ltd Petitioners 2006 CSOH 146
[2] [2006] EWHC 1089 (CH)
[3] Merrell Dow v Norton [1996] RPC 76
Anna McKay
December 2005
anna@annamckay.com
+44 (0)20 8347 8734
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