The peril of perindropil patent litigation

For those who like patents but don't want to spend their time reading all that law, here's a case that is pretty well all facts and arguments, with no analysis of statutes or earlier precedents at all. It's Les Laboratoires Servier and another v Apotex Inc and others [2007] EWHC 1538 (Pat), a Patents Court (England and Wales) decision handed down yesterday by Mr - soon to be Lord - Justice Pumfrey.

The two claimants (Servier) were the owner and exclusive licensee of a patent. The defendants (Apotex) belonged to a group of Canadian generic pharma companies. The patent was for "a new α crystalline form of perindopril tert-butylamine salt, a process for its preparation and pharmaceutical compositions containing it" (perindopril being an ACE inhibitor used in the treatment of hypertension). The patent in dispute claimed priority from a 2000 French application, but the original perindopril compound was patented in the early 1980s and another earlier patent for the compound patent 341) for "the industrial synthesis of perindopril" dated back to the late 1980s.

The patent was a lucrative one: Servier's turnover in the UK alone was £70 million and Apotex had sold £4 million worth of perindopril in the short period before Servier, alleging infringement, secured interim injunctive relief. Apotex then challenged the validity of the patent, while Servier sought leave to amend it. The problem, as Pumfrey J neatly summarised it, was not so much a matter of interpreting it, but rather that there was what he called "a lack of specification". In this hearing the principal issues were (i) whether the patent was anticipated and/or obvious in the light of patent 341 and (ii) if so, could Servier amend it?

Pumfrey J dismissed Servier's application to amend the patent, which he revoked. On the evidence, the patent's claims had been anticipated by, and lacked any inventive step because of, patent 341. Since the proposed amendments couldn't remedy this deficiency the patent was dead in the water.

The IPKat says, Pumfrey J made this observation in para.34 of his judgment in the context of the role of experiments in patent disputes:
"... the criteria for sufficiency of description on the one hand and the enablement of an inevitable result on the other are not the same. For the purpose of anticipation, the prior documents must enable something which inevitably falls within the claim. Where the prior art does not describe the end to be achieved, it is illegitimate to employ a refinement of technique or whatever to cause the desired result to be achieved. Where the sufficiency of a disclosure of a method is under discussion, ... the skilled person is entitled to do such preliminary work and carry out such uninventive refinements, without undue effort, with a view to producing a product falling within the claim".
Hypertension here, here and here
Hypertension in cats here
The peril of perindropil patent litigation The peril of perindropil patent litigation Reviewed by Jeremy on Thursday, July 12, 2007 Rating: 5


  1. Could someone please elaborate on "sufficiency of description on the one hand" and "the enablement of an inevitable result on the other". Thank you.

  2. It is explained in the rest of the quote. You just have to know that the standard for anticpation is the enablement of an inevitable result.

    He then compares that with what is needed for a sufficient description in a patent specification - which is more generous.

    Where the sufficiency of a disclosure of a method is under discussion, of course the skilled person is entitled to do such preliminary work and carry out such uninventive refinements, without undue effort, with a view to producing a product falling within the claim.

    The Ipkat only ellipsised out the of course in the quote.

    I wish the judge had interested himself more in where the inventive contribution in this patent might have been.

  3. Perhaps an example will help. Suppose the description of a patent says that, to achieve result X, you have to carry out steps A, B and C. If fact, to get result X you also have to carry out steps D and E - the patent doesn't actually mention these, but we'll assume that the person skilled in the art would realise that you have to do them to get result X. Or at least, the person skilled in the art would regard them as reasonable things to try to get the result. Is the patent insufficient? Probably not - the skilled reader can work out how to practise the invention.

    Now, suppose an earlier document is found. It tells the reader to do steps A, B and C, but it doesn't mention steps D and E or result X. Is this an anticipation? Probably not, as it doesn't tell you to carry out the necessary steps so following the instructions doesn't get you result X. Does it render the invention obvious? Again, probably not, as, if you don't know that you are trying to get result X, you have no particular reason to do steps D and E.

    So we have the strange situation in which a document telling you about steps A, B abd C may be a sufficient description but does not anticipate. The difference is that the patentee has said, in addition to describing steps A, B and C, that you want to get result X, and this is the new thing that he/she has provided.


  4. I guess people should also look at the Ramipril [Altace {R}] litigation in the US. The company extended its product life by claiming that the second patent covered substantially pure forms of the drug, while this was not adequately supported in the disclosure.
    But hey, its the US.. the company got to keep the life of the second patent.

  5. Refering to the example above, it has to be mentioned that the steps that were not explicitly stated in the 341 patent, are exactly what an expert would have done. It still freaks me out that the EPO came to a different conclusion but I am delighted to read that J. Pumfrey found a way to revoke the patent.

    BTW: Could anybody provide me with a copy of the judgment:



All comments must be moderated by a member of the IPKat team before they appear on the blog. Comments will not be allowed if the contravene the IPKat policy that readers' comments should not be obscene or defamatory; they should not consist of ad hominem attacks on members of the blog team or other comment-posters and they should make a constructive contribution to the discussion of the post on which they purport to comment.

It is also the IPKat policy that comments should not be made completely anonymously, and users should use a consistent name or pseudonym (which should not itself be defamatory or obscene, or that of another real person), either in the "identity" field, or at the beginning of the comment. Current practice is to, however, allow a limited number of comments that contravene this policy, provided that the comment has a high degree of relevance and the comment chain does not become too difficult to follow.

Learn more here:

Powered by Blogger.