UK – Cook Biotech v. Edwards Lifesciences / Appeal

Posted: June 28th, 2010

Cook Biotech Incorporated v. Edwards Lifesciences AG, High Court of Justice, Court of Appeal, London, UK, 28 June 2010, [2010] EWCA Civ 718

The Court of Appeal has dismissed an appeal against the decision of Kitchin J at first instance, finding the European Patent (UK) 1 255 510 (“the Patent”) invalid.


The Court of Appeal held that the first instance judge had been correct to hold the Patent invalid for obviousness:


i) the argument that the Patent was directed to an interventional cardiologist, and so should be read with the limited knowledge, functions and expectations of such a person, was fundamentally flawed. The Patent and the Andersen prior art patent were notionally addressed at the relevant time not just to an interventional cardiologist but to a team which included or would have consulted a cardiac surgeon and someone familiar with the design of implantable surgical heart valves.  They would have pooled their joint knowledge and experience when interpreting the Patent and Andersen;

ii) it is artificial, and counter-intuitive, to seek to make a clear division between the stent and the valve within it on the basis of functionality;

iii) Andersen reinforces the concept of a single stent, without meaningful differentiation according to the different functions it was performing;

iv) the appellant was wrong on the evidence to argue that part of the device had a function for which the interventional cardiologist was not responsible;

v) the minimum 1mm requirement in claims 15 and 22 was arbitrary, and merely there as a reflection of the obvious general need to secure and strengthen the edges of the valve and to prevent tearing.




Further on the facts


The Patent, called “stent valves”, is for an artificial heart valve within a radially expandable stent which can be delivered through a catheter. The appeal focused on the judge of first instance’s finding that claim 1, and claims 15 and 22 were obvious in light of the prior art patent called “Andersen” and the common general knowledge. The common general knowledge at the priority date was that replacement of heart valves was performed by a surgeon, requiring a major operation. However, treating problems within the heart and associated vessels (such as opening up narrowed heart valves) could be done percutaneously by interventional cardiology, performed by physicians, using a catheter to access the site in the heart and a balloon and stent to force open a particular vessel and keep it open. Andersen discloses a replacement heart valve comprising a heart valve from a slaughtered pig attached to an expandable frame constructed from two surgical steel wires, designed for implantation using a catheter.


The appeal against the Judge’s ruling that the Patent was obvious over Andersen turned on whether the Judge interpreted incorrectly the expression “radially expandable stent” in claim 1 of the Patent and the word “stent” in the Patent and in Andersen.  It was argued by the appellant that he failed to draw a proper distinction between the prior art function of a radially expandable stent, as known and used by interventional cardiologists at the priority date of the Patent, and the disclosure by the Patent of the adaptation of such stents to carry a valve. The appellant’s case on claims 15 and 22 was that the requirement that the valve slit should terminate at least 1mm from the stent perimeter to strengthen the edges of the valve was inventive.


Read the decision (in English) here.

Head note: Paul England

Leave a Reply