Intellectual Property

Article for Generics Web Feb 2007-02-18


Angiotech, Conor - not so Obvious.
Different approaches to considering inventive step

Angiotech, Conor, the Netherlands, England, paclitaxel coated stents - what happened ?

Another example of disagreement amongst the EPO, and different European countries - who is right?

The stent market is very lucrative, and is dominated by two companies, Johnson & Johnson and Boston Scientific. Stents are used to hold arteries apart, eg following angioplasty. Originally, stents were made of bare metal. Now, stents are often coated with products whose purpose is to restrain the proliferation of tissue which results in Restenosis, arterial blockage caused by scar tissue. Restenosis is a common problem following angioplasty. The Patentee, Vancouver- based Angiotech, developed and patented a stent coated with paclitaxel-containing polymer and licensed it to Boston Scientific, who have sold it under the 'Taxus' brand, very sucessfully, since 2005. Paclitaxel inhibits cell division - hence its utility as a cancer treatment. Conor Medsystems, a Californian company specialising in the development of drug-eluting coronary stents, developed a new kind of cobalt chromium stentwhich is pierced by holes designed to act as resevoirs to hold a polymeric/drug mix, specifically, a ploymer/paclitaxel mix.

Angiotech's European patent, no EPO 706 376, was amended by the European Patent Office, cut down, but, so far, survives. It claims paclitaxel/polymer-coated stents but gave very little description of them. Angiotech admitted that at the time of the application, no work had been done on such stents. That is perfectly acceptable - there is no legal objection to a patentee drafting and applying for a patent without leaving his armchair - but since a patented product or process must be capable of industrial application, it carries with it the risk that the product or process may not be able to be made or used, that the patent may turn out to be insufficient.

In the Netherlands, in two separate actions, Angiotech claimed that another Conor and another company, Sahajahand, were infringing its Dutch patent and applied for a cross-border injunction. Promptly after Angiotech had begun its action against Conor in the Netherlands, Conor applied to revoke Angiotech's English patent. The English case was heard firs in February 2006. Pumphrey J revoked the English patent. Next, in May, came the case against Sahajahand, and Sahajahand were determined to infringee. On Jan 16th 2007, the English Court of Appeal upheld Mr Justice Pumphrey's decision, and the next day, the District Court in The Hague whilst refusing a cross-border injunction against Conor, declined to follow the English decision. It knocked out one claim of the patent but held Conor to infringe and granted an injunction that was limited to the Netherlands. Angiotech has dismissed the English decision saying that 'the English court seldom upholds the rights of a patent holder'. FDA approval for Conor's stent is expected later this year. Let's look at the decisions, or at least the English ones, in more detail.

In England, in February 2006, at first instance, Mr Justice Pumphrey determined that the patent was invalid because the claimed invention was obvious. It was accepted that paclitaxel was well-known for its anti-proliferative qualities, that there was discussion in the art about coating stents with anti-angiogenic substances in order to prevent restenosis, and that the prior art did not specifically mntion paclitaxel. And, the patent merely claimed stents coated with a paclitaxel/polymer mix. It did not claim any particular efficacy for them, or disclose the use of any particular polymer. It merely claimed the idea of using stents coated with a paclitaxel/polymer mix. Pumphrey J said that in these circumstances the test must be whether or not it was obvious to try making (test) a stent coated with a paclitaxel/polymer mix at all. Given that the specification gave no idea of the likelihood of success, no indication of toxicity, it would be wrong to allow considerations of toxicity/lack of success to weigh against obviousness. It was not a valid argumant to say that the man in the art would have been put off using paclitaxel for local use because of its toxicity when no particular suitability for it was claimed. In his view, the patent was obvious, and the commercial success of the product was not, in this case, an indication that it had been inventive. Sometimes, the commercial success of a product (such as Mandy Haberman's famous 'AnyWayUp' cup ) can be used to show that an apparently simple idea was not obvious - - but in this case, the idea of coating stents was in the art, and the choice of paclitaxel for that purpose was not inventive.

On Februaty 16th 2007 the Court of Appeal rejected Angiotech's appeal against Mr Justice Pumphrey's decision. In an appeal against a finding of obviousness, the patentee has to show that the judge made an error of principle - not merely that he was wrong. This is a hurdle. The Court of Appeal did not accept that Pumphrey had made an error. Jacob L.J., giving the leading judgement, said : " All the patentee has sdone differently from [the prior art] is to name taxol as a suitable drug. A skilled reader is invited by [the prior art] to consider "other" anti-replicate drugs. Just to name one "other" anti-replicate drug, which on the information given in the patent is no more and no less likely to work in practise, is not to make an invention….Things would be different if the patentee had disclosed that taxol would be different, or better, or one of only a few that would work. His contribution to human knowledge would then be of value."

And in relation to the Dutch decision against Sahajahand Jacob L.J. said : " the Court took the vew that the patent was in effect a patent by selection - that the patentee had selected one..that would work out of a host of possibles…. That is to read the patent with hindsight knowledge that taxol stents work. This is just what the skilled man would not know, even by reading the patent…."

The day after the Court of Appeal decision, the District Court of the Hague decided that Conor infringed Angiotech's patent. One claim of the patent was declared invalid, but the rest survived. I have not seen the decision, but it seems that the court once again accepted that the patentee had made a valid selection.

Both of the English decisions are curious in the manner in which they characterise obviousness. Pumphrey J looks to the contribution made by the patentee, as well as to that which the skilled man would have known - an approach which is akin to the EPO's 'problem/solution' approach, and Jacob L.J. seems to be flagging to that way in which he thinks obviousness should be considered;

"One can, of course, postulate a different policy under which a [patent] monopoly might make sense. There are old or obvious ideas which take a lot of work, expense and time to develop and turn into something practical and successful. Without the incentive of a monopoly, people may not do that work or spend the time and money. The Fosamax case, Teva v Gentili [2003] EWHC 5 (Patent), [2003] EWCA Civ 1545, is an example of an obvious invention which cost lots to bring to market. But patent law provided no protection for all that investment because the basic invention was obvious. The courts' job is not, however, to uphold any claim to a monopoly for an idea which requires investment and risk to bring to market, only those for ideas which are new, non-obvious and enabled."

It will be interesting to see what the EPO finally decides.

Different standards? The European Patent Litigation Agreement may stop all of this. It is intended to simplify patent litigation by allowing European patents to be enforced in one set of proceedings covering all countries. I shall no doubt write about it in the future. Who do I think got it right? Is it true, as one writer has opined, that English specialised judges are to blame, that 'looked at from the point of view of Einstein, everything is obvious' ? Well, it is a hard balance, it is a political issue, and I do think that Mr Justice Pumphrey and the Court of Appeal got it right. But then I would, wouldn't I ?

Do let me have comments, And, if you think you may infringe a patent, or you want to knock out a patent, if you are considering where and how to take action, ask me !

P.S. On Feb 1, Johnson & Johnson agreed to buy Conor for (reportedly) US $1. 4 Billion.

Anna McKay, February 2007

  • 1  Master Cigars v Christopher Kenyon [2007] EWCA Civ 176
  • 2  (Art 36, Rome Convention)
  • 3  Master Cigars v Christopher Kenyon [2007] EWCA Civ 176 para 13
  • 4  Zino Davidoff -v- A and G Import [2001] ECR I-8691.
  • 5  Glaxo v Dowelhurst and Richard Taylor [2004] EWCA Civ 290
  • For more information on any of the above, contact me at:

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