Patents - Edwards Lifesciences v Meril

 

Jane Lambert

Patents Court (MrJustice Birss) Edwards Lifesciences Corporation and another v Meril GmbH and another [2020] EWHC 2562 (Pat) (29 Sept 2020)

This was an action for the infringement of EP (UK) 1 267 753 ("753") and EP (UK) 3 494 929 ("929") and a counterclaim for revocation of both patents on the grounds of obviousness, insufficiency and added matter.  The action and counterclaim came on for trial before Mr Justice Birss between 20 and 24 July and on 28 and 29 July 2020. His lordship handed down judgment on 29 Sept 2020. 

The Parties

The claimants are members of the Edwards Lifesciences Group.  Edwards Lifesciences Corporation held the patents and Edwards Lifesciences Limited. was its exclusive licensee.  The patents protect a range of prosthetic aortic valves that the claimants manufacture called "Sapien".  Those valves are implanted into a patient's heart by a catheter.  The technique is known as transcatheter aortic valve implantation ("TAVI").  The defendants are members of an India-based, global medical device group called Meril.  They also manufacture a transcatheter aortic valve which they call "Myval" and a catheter delivery system known as the "Navigator".

753

The invention for which 753 was granted is called a minimally invasive heart valve. No abstract is available for the European patent, but the abstract for the corresponding US patent is as follows:

"Expandable heart valves for minimally invasive valve replacement surgeries are disclosed. In a first embodiment, an expandable pre-assembled heart valve includes a plastically-expandable annular base having plurality of upstanding commissure posts. A tubular flexible member including a prosthetic section and a fabric section is provided, with the prosthetic section being connected to the commissure posts and defining leaflets therebetween, and the fabric section being attached to the annular base. In a second embodiment, an expandable heart valve includes an annular tissue-engaging base and a subassembly having an elastic wireform and a plurality of leaflets connected thereto. The annular base and subassembly are separately stored and connected just prior to delivery to the host annulus. Preferably, the leaflet subassembly is stored in its relaxed configuration to avoid deformation of the leaflets. The expandable heart valves may be implanted using a balloon catheter. Preferably, the leaflets of the heart valves are secured to the commissure regions of the expandable stents using a clamping arrangement to reduce stress."

929

This patent was granted for a low profile delivery system for transcatheter heart valve.  This is described in the following abstract by reference to the following drawing.

"A heart valve delivery apparatus (10) includes a valve carrying member. A prosthetic valve (12) is crimped onto the valve carrying member at a location that is distal or proximal to the balloon member (28), thereby providing a smaller profile delivery apparatus."

The Contentions

Edwards complained that Meril's Myval infringed claim 1 of 753 and that the Navigator infringed claims 1, 3, 4, 5, 6, 8, 9, 12 and 13 of  929.  Meril denied infringement and asserted that  753 was invalid for obviousness, insufficiency and added matter and that  929 also lacked an inventive step and was bad for added matter.

Claim 1 of 753

At paragraph [11] of his judgment, Mr Justice Birss divided claim 1 of 753 into the following integers:

"An A prosthetic heart valve, comprising:
B a support stent including a tubular base along an inflow end and a plurality of generally axially-extending commissure posts disposed evenly around the tubular base on an outflow end thereof,
C wherein the base is expandable from a first size adapted for minimally invasive delivery, to a second, functional size that fits within a heart valve annulus; and
D a flexible tubular member having a prosthetic section attached to the commissure posts so as to define a plurality of prosthetic valve leaflets between the posts;
characterised in that
E the tubular member further comprises a fabric section connected to the tubular base and only the fabric section contacts the tubular base."

Construction of Claim 1 of 753

The judge summarized the invention as follows at paragraph [86]:

"Claim 1 has been set out above. Broadly, it can be understood as a claim to a device - a prosthetic heart valve. The device has two parts - a support stent and a flexible tubular member. The support stent includes a tubular base which is expandable (feature C) and commissure posts. The flexible tubular member has a prosthetic section attached to the commissure posts (feature D in part). The characterising feature (E) is that the tubular member further comprises a fabric section connected to the tubular base and then crucially 'only the fabric section contacts the tubular base'”.

There were two disputes on construction.

The specification disclosed two embodiments of the invention. Meril argued that claim 1 covered only the first embodiment "in that the leaflet material is actually made from a single continuous tube and the valve leaflets only take shape as a result of the geometry of the attachment of the tube material to the metal structure."  Meril contended that a device like the second embodiment, in which the leaflets were formed from three distinct pieces, was not within claim 1. Edwards argued that Meril's contention was wrong reading the document as a whole. It argued that in the assembled structure there is a flexible tubular structure regardless of whether the leaflets are composed of a single tube or of distinct pieces. Edwards also submitted that the language of feature D (“defining”) is apt to cover both arrangements and does not exclude leaflets made of distinct pieces.

The judge agreed with Edwards because "the skilled reader would understand the patent as a whole to be written on the basis that both embodiments are embodiments of the invention, that is to say the invention claimed in claim 1."  However, he acknowledged that the first embodiment fitted claim 2 more easily than the second.

The other argument was whether the lower rows had greater radial strength than the top row,  His lordship found that the lower two rows had smaller cells in order to have higher radial strength while the upper rows are more open so as to avoid occlusion.

Whether the Myval fell within  Claim 1

This is a photo of the Myval valve:

The judge described it as follows in paragraph [101]:

"The structure is built from a single nickel cobalt alloy cage formed of hexagonal cells. The cells in the upper row are larger than the cells in the lower two rows. There are three preformed leaflets made of bovine pericardium stitched at their lower edge to a fabric skirt. The fabric skirt is attached to a frame. The fabric skirt is made of an inner skirt and an outer skirt. The commissures of the leaflets attach to slots in vertical struts which are part of the cage."

He added at [107]:

"In terms of claim 1 the lower two rows of cells of the Myval amount to a tubular base while the three relevant struts are commissure posts extending axially and disposed around the tubular base."

He concluded that the Myval fell within claim 1.

Invalidity of Claim 1 of 753 on Grounds of Obviousness

The judge turned to the counterclaim for revocation under s.72 (1) (a) of the Patents Act 1977. Meril argued that the invention was not patentable because it lacked an inventive step.  It will be recalled that s.3 provides that 

"An invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art by virtue only of section 2 (2) above (and disregarding section 2 (3) above)."

Meril contended that claim 1 was obvious in the light of published application WO 98/29057 (“Cribier”)  when read in conjunction with US Patent 5,411,552 (“Andersen”) which was cross-referred to and discussed in Cribier.  It was common ground that the person skilled in the art would be a team consisting of at least an interventional cardiologist and a biomedical engineer. Meril had argued that a cardiac surgeon would also be needed but the judge held that common general knowledge that such surgeon could contribute would already be known by the other members.   The judge described the common general knowledge of that team between paragraph [25] and paragraph [47] pf his judgment.  Although his lordship did not refer expressly to the Windsurfing/Pozzoli test as approved by the Supreme Court in Actavis Group PTC EHF and Others v ICOS Corporation and another [2019] Bus LR 1318, [2019] UKSC 15, it is clear that he applied it,   He concluded at [155] that claim  1 of 753 lacked an inventive step:

"One of the obvious ways forward for a skilled team given Cribier in 2000 would be to construct an implantable valve with a metal frame and commissure posts, a valvular structure based on pericardial leaflets and an internal cover made of fabric based on any of figures 6a-d with the leaflet material connected to the fabric and not the metal base part."

Insufficiency of 735

Referring briefly to Regeneron Pharmaceuticals Inc v Kymab Ltd [2020] Bus LR 1394, [2020] UKSC 27 Mr Justice Birss found that a skilled team would have no difficulty in constructing either of the embodiments in claim 1 from the patent.

Added Matter in Relation to 735

Meril had argued that integer E was only disclosed in the first embodiment and not in the second.   The judge rejected that argument at [160]:

"The reader of the application as a whole would understand that how the leaflets are attached is an important part of the teaching. The summary of the invention as set out in the application as filed at p2 ln25-p3 ln6 describes the invention as a product in which, amongst other things, the leaflets are attached to the commissure posts (and the cusp edge). Notably it does not say that the leaflets are attached to the tissue engaging base and the reader would not think that that was what was being suggested. When the document does refer to attachment to the base, the leaflets are not directly attached to the base, they are attached to the fabric section, which is itself attached to the base. It is true that the explanation of why one would attach the leaflet to the fabric section this way is given in relation to the first embodiment (p11 ln21-26) but the skilled reader would understand that to be generally applicable. Therefore there is no intermediate generalisation and no added matter."

Conclusion on 735

The Myval would have infringed claim 1 had it been valid but as the claim was bad for obviousness the claim for infringement of 735 failed.

Claim 1 of 929

The judge broke claim 1 into the following integers at paragraph [14]:

"A.   A delivery system for delivering a prosthetic aortic heart valve to a patient’s native aortic valve, comprising:
B a balloon catheter comprising an elongated shaft and an inflatable balloon mounted at a distal end of the elongated shaft, and
C a flex indicating device comprising:
D a guide catheter comprising a handle portion and an elongated guide tube extending distally from the handle portion,
E the elongated shaft of the balloon catheter extending coaxially through the elongated guide tube;
F at least one pull wire connected to a distal end portion of the elongated guide tube;
G wherein the handle portion comprises a flex activating member, the flex activating member being coupled to the at least one pull wire such that manual adjustment of the flex activating member causes the distal end portion of the elongated guide tube to flex;
H the flex indicating device further comprising a flex indicating member,
I wherein manual adjustment of the flex activating member causes the flex indicating member to move relative to the handle portion to indicate an amount of flex of the distal end portion of the elongated guide tube,
J wherein the flex indicating device further includes indicia indicating the amount of flex of the distal end portion of the elongated guide tube, the indicia being provided at the handle portion,
K and wherein the handle portion comprises a slot for receiving at least a portion of the flex indicating member."

Construction of Claim 1 of 929

His lordship analysed the patent between paragraph [161] and [177] and considered claim 1 between [178] and [203].

Whether the Navigator infringed Claim 1 of 929

The following is an overview of the Navigator delivery system for the Myval device.

Edwards argued that the Navigator infringed claim 1 on a literal construction:

• a balloon catheter was made up of the inner shaft and the inner liner (as well as the soft tip and the balloon)
• the fluid used to inflate the balloon passed in the space between the inner shaft and the inner liner'
• the guide catheter was the proximal handle and the outer shaft, excluding the inner liner and it was that part of the outer shaft which extended to and included the metal ring;
• the elongated guide tube of the guide catheter was the outer layer and the mesh layer; and 
• the inner layer and the inner shaft extended coaxially through that elongated guide tube so defined. 

Edwards submitted that there were two catheters, both physically and functionally distinct and so the claim was satisfied.

The learned judge disagreed.   The simple answer in his view was that the skilled person would regard the outer shaft of the Navigator as a single composite structure. No reader of the patent would think it made sense to divide up such a single composite structure in that way to try and make it fit within the claim.   His lordship held that on a literal construction the Navigator did not fall within claim 1 of 929.

However, that was not quite the end of the story because art 2 of the Protocol on the Interpretation of art 69 EPC required the trial judge to take account of any element that was equivalent to an element specified in the claims.   At paragraph [221] Mr Justice Birss referred to the "Improver questions" re-formulated by the Supreme Court in Eli Lilly v Actavis UK Ltd and others [2017] RPC 21, [2017] Bus LR 1731, [2017] UKSC 48 to determine whether an element was equivalent to an element in a claim:

"Question 1: does the variant achieve substantially the same result in substantially the same way as the invention?
Question 2: Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention?
Question 3: Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?"

He also recalled Lord Justice Kitchin's amplification in  Icescape Ltd v Ice-World International BV and Others  [2018] EWCA Civ 2219:

"The first Improver question, whether the variant has a material effect on the way the invention works, was addressed by Lord Neuberger at [60]. He thought this was generally satisfactory but the court must focus on "the problem underlying the invention", "the inventive core", or the "inventive concept". In effect the question is whether the variant achieves the same result in substantially the same way as the invention".

At [223] Mr Justice Birss interpreted that to mean:

"In other words one should examine what is the problem underlying the invention and how does the patent solve that problem."

The judge asked those questions between paragraphs [285] and [290] of his judgment and found that the Navigator would infringe claim 1 under the doctrine of equivalents if that claim was valid.

Infringement of other Claims

It will be recalled that Edwards claimed that the Navigator infringed 8 of the claims of 929 in addition to claim 1.  It also alleged that claims 1, 2, 4, 5, 7, 8, 9, 11, 12 and 13 were independently valid.   His lordship protested at paragraph [15] that far too many claims had been maintained as independently relevant, Had he spotted that at the pre-trial review, he would have restricted that number drastically. Nevertheless, he considered whether claims 3, 4, 5, 6, 8, 9, 12 and 13 had been infringed between paragraph [229] and [241].   He found that the Navigator had infringed them all.

Whether 929 was Obvious

Meril claimed that 929 was obvious in the light of US patent application US 2008/0065011 A1 (“Marchand”), application WO 2004/039273 (“Falwell”) and two of Edwards’ products called Retroflex I and Retroflex II respectively. The skilled addressees were the same as for 735 and their common general knowledge included the matter between paragraphs [48] and [62] as well as the matter relating to 735.  Again it appears that the judge applied the Windsurfing/Pozzol test even though he did not refer to the test by name.

He concluded at [253] that claim 1 was obvious over Marchand.    As claim 2 was dependent on claim 1 he decided at [256] that claim 2 fell with claim 1.   Claims 4 and 5 were distinct from Marchand and a knob, as opposed to a rotatable lever, would not have been obvious.   He held that claim 7 would not fall with claim 1.   Claims 8 and 9 were not obvious and as claims 11, 12 and 13 were dependent on claims 8 and 9 those claims would not fall either. 

Comparing 929 to the Retroflex he decided that claim 1 was not obvious over that product.   As the features of claims 7, 8, 9, 11, 12 and 13 were in Retroflex, those claims stood or fell with claim 1 and claims 4 and 5 were independently inventive.

Finally, the judge considered and rejected the case based on Farwell at paragraph [280].

Added Matter in Relation to 929

The judge could find no basis for that argument.

Conclusion on 929

His lordship found that the Navigator infringed claims 4, 5, 8, 9, 12 and 13 and would have infringed claims 1 and 2 had they been valid.

Further Information

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