The heart of the matter: one patent, two views

This guest blogpost comes courtesy of Katfriend and occasional contributor Suleman Ali (Holly IP), a patent attorney whose interest lies mainly in the biotech and medical fields --an interest that is quite germane to the case he writes about here about a patent for a collapsible device for filling holes in the heart and how a trial judge and an EPO Opposition Division could reach quite different conclusions when confronted with essentially the same evidence:

AGA Medical Corporation v Occlutech (UK) Limited [2014] EWHC 2506 (Pat) is a decision by Mr Justice Roth in the Patents Court, England and Wales. AGA Medical claimed that Occlutech had infringed its patent EP (UK) No. 0,957,773 to a medical device for occluding defects in the atrial septum of the heart. Occlutech responded that the patent was invalid on the basis of a prior disclosure in a clinical trial and on other grounds. An EPO Opposition Division had revoked the same patent last year, and is in appeal from that decision. 

Issues of Interest 

 This judgment has the following interesting points:

* a discussion of the case law on confidentiality.

* a finding that a clinical trial did constitute novelty-destroying disclosure. The EPO Opposition Division found the same clinical trial to be confidential and thus not novelty-destroying.

* a discussion of when an ‘intermediate generalisation’ adds matter, in particular where features which are not presented as ‘inventively distinct’ and are disclosed in a particular context are used as the basis of amendment. In the present case Mr Justice Roth held that the amendments did not add matter, but the EPO opposition division held that they did. 

The technology 

The patent concerns a device which can be used to fill a ‘hole in the heart’, i.e. a hole in the wall (the septum) between the two parts of the heart. The device is collapsible and in its collapsed form can be passed to the heart through a blood vessel using a catheter, thus avoiding the need for open heart surgery. The device is shown in the adjoining figure in the form it adopts to seal the hole in the septum. It is formed of two discs joined by a thinner cylindrical waist and is made of woven strands of a ‘memory metal’ which resumes its shape after being compressed. When inserted into the hole the discs occupy a position on either side of the wall keeping it in place. At least one of the discs is ‘cupped’ (rather than flat) which means only the perimeter of the disc contacts the septum, and this allows a tight join. 

Claim 1 of the patent as presented in the decision is as follows:

"A collapsible medical device, comprising
(1) a plurality of metal strands forming a tubular braided metal fabric having an expanded preset configuration,
(2) the ends of the strands of the tubular braid being secured in order to prevent the strands from unravelling,
(3) wherein said medical device is shaped to create an occlusion of an abnormal opening in a cardiac septal wall,
(4) whereby said expanded preset configuration is deformable to a lesser cross-sectional dimension for delivery through a channel in a patient's body,
(5) the woven metal fabric having a memory property such that the medical device tends to return to said expanded preset configuration when unconstrained,
(6) the expanded preset configuration comprising first and second expanded diameter portions respectively at distal and proximal ends of the device and a reduced diameter portion disposed between the two expanded diameter portions, said reduced diameter portion having a length dimension which approximates a thickness of the septal wall at the abnormal opening,
(7) wherein at least one of said first and second expanded diameter portions is cupped towards the other of the expanded diameter portions causing, in use, the perimeter edge of the cupped expanded diameter portion to fully engage the sidewall of the septum,
(8) the collapsible medical device further including an occluding fiber retained within said tubular woven fabric."

Other Proceedings 

The parties have been in litigation before in the UK over an earlier patent (see Occlutech GmbH v AGA Medical Corporation [2009] EWHC 2013(Ch), upheld on appeal [2010] EWCA Civ 702, reported by the IPKat [see here and here]. The IPKat has also previously reported litigation between the parties in Sweden [see guest post by Peter Kenamets, here]. In the case of the present patent there is ongoing litigation between the parties in a number of jurisdictions, including the Netherlands. As mentioned above, the patent is in appeal at the EPO from a decision of the Opposition Division. 

Prior Use In A Clinical Trial 

Before the priority date a clinical trial was carried out using AGA devices in three children in the Bratislava Children’s University Hospital. Two important issues arose from this:

* did the devices that were used have at least one or two ‘cupped’ discs (rather than flat discs)?
* was the trial confidential?

The doctors that had taken part in the trial gave evidence. Dr Gougen’s evidence indicated none of the devices was cupped, though he admitted this was something he might not have noticed. Professor Masura's recollection was clearer: he said that two of the devices had cupped discs. Mr Justice Roth found him to be ‘a very clear witness’ and ‘found his evidence convincing’. Dr Gavora said all three of the devices had cupped discs. However his evidence was less convincing and it was noted that he had previously given contradictory answers on the same issue before a Dutch Court. Clearly there were significant discrepancies between the evidence of the witnesses, but Mr Justice Roth came the conclusion that ‘at least some of the three devices’ used in the trial had cupped discs. 

The Opposition Division was much more critical of the evidence given by the same witnesses and decided that it was ‘not convinced’ that any of the devices used in the clinical trial had a cupped disc. 

Were the Trials Confidential? 

Mr Justice Roth gave emphasis to the following paragraph from Coco v AN Clark (Engineers) Ltd [1969] RPC 41 on the circumstances in which confidentiality is imposed:

"It seems to me that if the circumstances are such that any reasonable man standing in the shoes of the recipient of the information would have realised that upon reasonable grounds the information was being given to him in confidence, then this should suffice to impose upon him the equitable obligation of confidence. In particular, where information of commercial or industrial value is given on a business-like basis and with some avowed common object in mind, such as a joint venture or the manufacture of articles by one party for the other, I would regard the recipient as carrying a heavy burden if he seeks to repel a contention that he was bound by an obligation of confidence"

He noted that none of the doctors involved in the clinical trial had been asked to sign a confidentiality or non-disclosure agreement. They gave evidence that they had never been given the impression that the devices were confidential. In addition he felt that ‘there is no presumption of confidentiality simply because this was a clinical trial. Everything depends on the facts’. Professor Masura had spoken about the devices in briefing sessions to other doctors at the hospital and had described the device and clinical trials at a presentation at a conference. He had acted in a way that he did not seem to perceive himself to be under a duty of confidence. It was also clear that the doctors were not embarking on a commercial venture, so the disclosure of the devices was not done in a ‘business-like’ way that may have led to an assumption of confidentiality. 

Mr Justice Roth also considered Carflow Products (UK) Ltd v Linwood Securities (B’ham) Ltd [1996] FSR 447 as to the circumstances in which an equitable obligation of confidence arose. In that case Jacob had said that, on an objective basis, an obligation of confidence is not imposed merely because a prototype is being offered for sale. 

Mr Justice Roth concluded the clinical trial had not been confidential and that it therefore destroyed the novelty of the patent. However he added that the EPO's Opposition Division had reached the opposite conclusion: the fact it was a clinical trial gave rise to a prima facie assumption of confidentiality which had not been rebutted. The Opposition Division had based its view on decisions T906/01, T152/03 and T229/06. However, I believe there are EPO decisions that would have supported Mr Justice Roth’s position on whether a clinical trial per se is confidential, such as T158/96 and T7/07.

Obviousness Over an Earlier Prototype 

Dr Gu of AGA had disclosed an earlier prototype of the device in a presentation at a medical congress before the priority date. That device had two flat discs, i.e. no cupped discs. In the present case the obviousness analysis was essentially to determine whether a device with one or two cupped discs was obvious from the disclosure of the earlier prototype by Gu. On this question Mr Justice Roth accepted the view of one of the expert witnesses, Professor Gewillig, that the skilled person presented with the earlier prototype would know that a flat disc device would lead to a serious risk of clotting due to thrombus formation in areas where the flat disc did not fully contact the septum. The skilled person would seek ways to avoid this risk, and adapting the earlier prototype to introduce cupped discs was an obvious modification that could be derived from prior art devices. One of AGA’s expert witnesses had argued that the alternative solution of shortening the waist would be adopted instead. In response Mr Justice Roth pointed out that the fact there may be a number of other obvious modifications did not mean the modification at issue (introducing cupped discs) was not obvious. 

Insufficiency 

Occlutech’s argument on insufficiency was based on the fact that claim 1 required the disc edge to ‘fully engage with the sidewall of the septum’. They submitted this meant there could be no gaps all the way round the disc edge. That was difficult to achieve and impossible to measure. Mr Justice Roth said the skilled person would not read this feature literally, realising that the septum is not completely flat and there will be points of no contact. Thus ‘full engagement’ does not require ‘perfect engagement’ and any gaps would be ‘insignificant and unintentional’. Construing the feature in this way led to the insufficiency attack failing. 

Added Matter 

Two of the four added matter attacks are discussed here. The first attack alleged that claim 1 added matter because the requirement of each end being ‘contained by means for securing each end’ had been deleted from the claim as filed. The arguments were lengthy and complex on this point, but ultimately Mr Justice Roth found the amendment did not add matter because the application taught a method which could be used to produce a device a device according to claim 1 where one end was not secured. 

The EPO Opposition Division had taken the opposite view. It applied the 3-part test described in the Guidelines at Part H, Chapter V-3.1: 

‘The replacement or removal of a feature from a claim does not violate Art. 123(2) if the skilled person would directly and unambiguously recognise that: 

(i) the feature was not explained as essential in the disclosure; (ii) the feature is not, as such, indispensable for the function of the invention in the light of the technical problem the invention serves to solve; and (iii) the replacement or removal requires no real modification of other features to compensate for the change.’

The EPO found the amendment to fall foul of all 3 limbs of the test and therefore to add matter. 

The second added matter attack of interest was based on introduction of the feature of one or both discs being ‘cupped’. While this feature became important in determination of novelty and inventive step it was not in the claims of the application as filed and is essentially only disclosed as part of specific embodiments shown in the Figures. 

Adding the feature to claim 1 was an ‘intermediate generalisation’. Mr Justice Roth noted from Palmaz’s European Patents (UK) [1999] RPC 47 that:

"If the specification discloses distinct sub-classes of the overall inventive concept, then it should be possible to amend down to one or other of those sub-classes, whether or not they are presented as inventively distinct in the specification before amendment. The difficulty comes when it is sought to take features which are only disclosed in a particular context and which are not disclosed as having any inventive significance and introduce them into the claim deprived of that context. This is a process sometimes called 'intermediate generalisation'."

The application did have some discussion of the cupped feature, describing how it ensured complete contact with the septum and the fact that this would reduce the chance of bacterial endocarditis. Mr Justice Roth felt this made it clear to the skilled person that the feature was not tied to other features of the specific embodiments, and so could be added to claim 1 without adding matter. 

Again the EPO Opposition Division had taken the opposite view, holding that the feature of the discs being cupped was tied to the feature of the discs being of different sizes, and therefore generalising the feature to the device of claim 1 added matter. 

Infringement 

It was decided that, if the patent were valid, Occlutech’s devices would have infringed. 

Occultech had also asked for a declaration of non-infringement for a specific device which did not have fabric within the hollows of the disc. Mr Justice Roth indicated that such a declaration would have been given if the patent had been found to be valid. 

Conclusions

It is striking that Mr Justice Roth and an EPO Opposition Division managed to reach such different conclusions on every point that was being decided on this case, though they had substantially the same evidence in front of them. It is not unexpected that the Opposition Division was stricter on evidence relating to a prior use disclosure and on added matter. However it does lead one to question whether more could be done to achieve harmony between national courts and the EPO.

Thanks so much, Suleman! Readers: could more have been done to achieve harmony between national courts and the EPO?