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