Balloons and oxymorons -- the Lords' decision

Further to this morning's earlier posts (see immediately below), the IPKat can now say a bit about the approach taken by the House of Lords to the proper test of inventive step in Conor Medsystems Inc v Angiotech Pharmaceuticals Inc. The facts, taken from the judgment of the trial judge, were as follows. Angiotech owned a European patent designating the UK for a stent used in coronary angioplasty. the basic idea of a stent is that, when it is inserted into a diseased artery in the course of angioplasty, a little balloon can be inflated which keeps the artery open.

Right: the humble balloon was part of the prior art -- they work best with taxol, though

Angiotech's patent claimed a stent coated with a polymer which was loaded with the drug taxol: this inhibited the development of tissue that might result in the gradual closure of the artery (a condition known as restenosis). Angiotech licensed the patent to Boston Scientific, which made stents. Conor, a competitor of Boston Scientific, sought to revoke the patent, claiming that it was obvious in the light of the prior art.

Pumfrey J allowed the application and revoked the patent. The mere fact that no-one had used stents like this before might make them new, but it didn't make them non-obvious. Given the state of the art, it was obvious to anyone who needed a stent of this nature that he would have to use taxol. Accordingly, in his view, the patent was invalid for obviousness. The Court of Appeal, for whom Lord Justice Jacob delivered the judgment, dismissed Angiotech's appeal.

Today the House of Lords took a different view, allowing the appeal and affirming the validity of Angiotech's patent. The opinion of their Lordships is contained in the speech of Lord Hoffmann, to whose words Lord Walker of Gestinthorpe could add nothing useful. Lord Hoffmann said as follows:

"2. Since the decision of the Court of Appeal, Angiotech and Conor have reached a settlement. Conor does not oppose Angiotech’s appeal. But a patent confers proprietary rights in rem and the validity of a patent cannot be established simply by a judgment in default of opposition. Your Lordships therefore invited the Comptroller General of Patents to assist the court in presenting what appeared to him to be the arguments against the validity of the patent. ...

3. There is still no European Patent Court. A European patent takes effect as a bundle of national patents over which the national courts have jurisdiction. It is therefore inevitable that they will occasionally give inconsistent decisions about the same patent. ... Sometimes one is dealing with questions of degree over which judges may legitimately differ. ... In this case ... there is a question of principle at stake. It is about how you identify the concept embodied in the invention which may constitute the “inventive step” for the purposes of article 56 of the EPC and section 1(1)(b) of the Patents Act 1977. ...

12. The Angiotech stent has been a great commercial success. It has the largest share of the market in drug eluting stents, which have very considerably reduced the incidence of restenosis.

17. ... It is the claimed invention which has to involve an inventive step. The invention means prima facie that specified in the claim: .... In the present case, the invention specified in claim 12 was a stent coated with taxol. There was no dispute that this was a new product. The question should therefore simply have been whether it involved an inventive step. As in the case of many product claims, there was nothing inventive in discovering how to make the product. The alleged inventiveness lay in the claim that the product would have a particular property, namely, to prevent or treat restenosis. ... So the question of obviousness was whether it was obvious to use a taxol-coated stent for this purpose. And this, as I have said, was the question to which the experts addressed themselves.

18. [Counsel for Conor] sought to avoid this question by watering down the claimed invention by reference to what he said were inadequacies in the specification. It did not contain information about human or animal tests which showed that it would work or provide enough information about doses and so forth to enable the skilled person to work it. It was therefore nothing more than an idea that taxol might work and any skilled person would have known that.

19. In my opinion, ... the invention is the product specified in a claim and the patentee is entitled to have the question of obviousness determined by reference to his claim and not to some vague paraphrase based upon the extent of his disclosure in the description. ...

28. The question was whether that was obvious and not whether it was obvious that taxol (among many other products) might have this effect. It is hard to see how the notion that something is worth trying or might have some effect can be described as an invention in respect of which anyone would be entitled to a monopoly.

Left: is this truly an oxymoron--or is it merely two individual contradictory statements?

It is therefore perhaps not surprising that the test for obviousness which Pumfrey J devised for such an “invention” was whether it was obvious to try it without any expectation of success. This oxymoronic concept has, so far as I know, no precedent in the law of patents. ...

37. The Court of Appeal upheld the judgment of Pumfrey J on the ground that the patent contained no “disclosure” saying that taxol was specially suitable for preventing restenosis. .... But there is in my opinion no reason as a matter of principle why, if a specification passes the threshold test of disclosing enough to make the invention plausible, the question of obviousness should be subject to a different test according to the amount of evidence which the patentee presents to justify a conclusion that his patent will work. ...

40. In the event, ... neither the judge nor the Court of Appeal answered what I consider to have been the correct question, namely, whether it was obvious to use a taxol-coated stent to prevent restenosis. ...

42. In the Court of Appeal, Jacob LJ dealt comprehensively with the question of when an invention could be considered obvious on the ground that it was obvious to try. ...

43. But Jacob LJ rejected this approach ... because “the patent has not in any way demonstrated that taxol actually works to prevent restenosis.” I agree with the Dutch court that patent law does not require such a demonstration. It was not a sufficient reason for not applying the ordinary principles of obviousness to the claimed invention. I would therefore allow the appeal".

It seems to the IPKat that Lord Hoffmann has sought to claw back the test of inventive step from the jaws of analytical oversophistication and to bring it back to basics. "Obvious to try" is a valuable tool for enabling patent lawyers to gauge the degree (if any) of inventive step in a patented invention, but it is only a means -- and not even an exclusive means, at that -- of assisting the court to reach a conclusion.

Right: this is how arteries get furred up ...

He also speculates whether his Lordship's comment at para. 12, relating to the patented product's great commercial success, throws a significant ray of light on Lord Hoffmann's thought-processes; in its day, "commercial success" was often a carefully deployed argument in favour of a patent's non-obvious nature. But the reality is that the test of inventive step is one that applies to the invention as patented, as embodied in its claims, not by the success or failure in the marketplace of any manufactured product which incorporates its functions. Merpel says, is that the sound of Champagne corks I hear from the celebrating Angiotech -- or is it the popping of stents?
Balloons and oxymorons -- the Lords' decision Balloons and oxymorons  -- the Lords' decision Reviewed by Jeremy on Wednesday, July 09, 2008 Rating: 5


  1. Interesting judgment. Maybe I'm being dumb, but surely Para 19 begs the question: if "invention" is as wide or narrower than the "inventive concept" (which it must be in view of s.14(5)) and you therefore can't paraphrase the claim and/or the description to construe the inventive concept, is the inventive concept not ultimately the claim as worded in its entirety read in the context of the supporting description and diagram, ie step 3 of the reformulated 5 stage Windsurfing test becomes irrelevant...?

  2. Well, at least the chemists are happy. They can go on filing their new apps as soon as they have a "plausible" story of selection to tell. The evidence can come later. Pumfrey was a physicist, so presumably was looking for a purposive selection of taxol, from Wolff's class "anti-angiogenics". Seems to me that inventor Hunter just took the a-a of the moment, taxol, and his patent attorney put his exptal results into the app. Did Hunter say "taxol works better than the rest"? No. Did he make a purposive patentable selection? I remain unconvinced. But then, I'm not a chemist either.

  3. Max, I'm no physicist, but a chemist, so maybe I am just "happy", but surely the patent DID say Taxol works better than the rest? Example 2, quoted by Lord Hoffman seems pretty black and white to me. Now it is true that there is a whole lot of chaff there too as Lord Walker points out not o do with stents, etc. But I don't see how you can say that example 2 dosn't say Taxol was best. To quote: "Taxol-treated avascular zones also revealed an abundance of cells arrested in mitosis in all three germ layers of the CAM; this was unique to taxol"; and further "It has been found that the avascular zone formed by heparin and angiostatic steroids became revascularized 60 hours after application. In our study, taxol-treated avascular zones did not revascularize for at least 7 days after application implying a more potent long-term effect".

    In other words, taxol worked better than the rest. Considerably better.

    Cheers, Luke

  4. Thanks Luke. That's pretty conclusive. You must find Example 2 difficult to reconcile with the Pumfrey view that the reader of Angiotech gets nothing more than the reader of Wolff. I had supposed, from the Pumfrey decision, Angiotech's Example 2 to be just confirmation of the Wolff-predicted mitosis arrest, and that skilled readers of Angiotech as filed were being lead to believe that other members of Wolff's class, if tested, would have performed just as well as taxol. Still, Hunter did actually test taxol, and report on it, as you say, and that's how to get a valid chemical patent.

  5. MaxDrei, by "purposive selection" do you mean to refer to selection inventions? If so, then it would appear that this was not relevant in the case. Selection inventions give novelty. The invention was clearly already new - what was at issue here was inventive step.

    In Angiotech's defence, the patent did disclose data showing that taxol worked better than anything else tested (the CAM test, paras 9 and 21). This was an in vitro test for angiogenesis, not prevention of restenosis as such. But their Lordships considered that a skilled person reading the patent would have understood that in principle taxol would work to prevent restenosis. See the last 3 sentences of paragraph 39 ("...the teaching of the patent was to use an anti-angiogenic factor on a stent to prevent or treat restenosis...the CAM assay taught that taxol was the best anti-angiogenic"). This was enough to give plausibility to the claimed invention.

    It's an issue that everyone working in biotech, pharma and chemistry grapples with - how much work you need to have done (and how much data to disclose) before you file. Your client is never going to have made and tested everything from bench to bedside, and then be in a position to file. No one can build a business on this model. It's a comfort to know that their Lordships recognise this, too.

  6. The HOL's judgment seems like a missed opportunity. Their Lordships had the chance to clear up the issue inventive step under English law, by either endorsing Windsurfing / Pozzoli (the subtraction exercise that is loaded with hindsight) or endorsing the EPO approach (lets patentees get away with obvious developments as long as they can find an appropriate technical effect). They have done neither. (There were some efforts in Ranbaxy v Warner Lambert at first instance a few years back to crowbar in the EPO approach into English law but they came to nothing). Their Lordships appear to have left us in a bit of a no-mans land. There is a hint that motivation to take a step away from the prior art to arrive at the claimed invention is now a relevant consideration when considering inventive step, but I don't think there is enough in this judgment to for a Patents Court Judge a Court of Appeal judge to say that Windsurfing / Pozzoli is now in the bin. Shame.

  7. Chong Yee Khoo: doesn't a "selection" have to both novel and non-obvious to be patentable? Are there not selections that are novel, yet obvious? Didn't Wolff already propose to coat stents with something anti-angiogenic? Anonymous: consider Angiotech from the EPO point of view, nanmely, what is the "objective technical problem"(imperative to exclude hindsight). Hoffmann agreed with the Dutch court and disagreed with Pumfrey. For PSA, definition of the OTP is key, and so where the heat of argument between the parties is at its most intense. If you lose that battle, you lose the war. I don't accept that PSA, properly executed, lets obvious stuff through to issue. I too think it's a shame that its merits continue to be unrecognised by the English courts. Mind you, no other national courts get it either. Not invented here syndrome, perhaps.

  8. And yet Hoffmann says "So the question of obviousness was whether it was obvious to use a taxol-coated stent for this purpose". Surely that isn't the question? The claim referred to the product not to its use and use is a different category (a method). Isn't his first question wrong? The product can even be not new while its use or uses may all be new and not obvious!

  9. For pharma and biotech the message should be "guess without hard data, but guess right". If post-published data agree with your guess (with your formulation of the technical problem), everything is fine. If not, you have a problem with sufficiency.

    However, if like in T 1329/04 , your guess of possible function is so broad to be all over the place, later confirmation of part of that guess is not acceptable.

  10. Some Americans disparage "First to File" with the logic that it works against the public interest, by forcing filings before the invention has been properly made. One has the feeling that Nick Pumfrey might have been susceptible to such criticisms, while Lord Hoffmann today has more reason to be confident that the EPO will be filtering out the premature filings with Art 83 and 84 EPC. Could it be that both are right? The EPO's resolve to refuse is stiffer these days, no? BTW readers, any theories why nobody attacked the validity of this patent in Germany?

  11. MaxDrei,
    I suspect the reason is that by the time the opposition proceedings had finally terminated, the parties had resolved the issues and therefore no need to file a revocation action.


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