Patents - Edwards Lifesciences v Meril
Patents Court (MrJustice Birss) Edwards Lifesciences Corporation and another v Meril GmbH and another  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 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".
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."
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.
"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."
"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'”.
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.
This is a photo of the Myval valve:
The judge described it as follows in paragraph :
"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 :
"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.
"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."
Conclusion on 735
"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."
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.
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  Mr Justice Birss referred to the "Improver questions" re-formulated by the Supreme Court in Eli Lilly v Actavis UK Ltd and others  RPC 21,  Bus LR 1731,  UKSC 48 to determine whether an element was equivalent to an element in a claim:
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?"
Finally, the judge considered and rejected the case based on Farwell at paragraph .