Edwards Lifesciences LLC v Boston Scientific Scimed, Inc. & Ors

In assessing patent validity, the skilled team and common general knowledge must be identified by reference to practical experience in the relevant field. Patent claims receive a purposive construction. Knowledge that a patent is divisional may explain differences between claims and examples, but does not impose rigid assumptions on the skilled reader.

Anticipation requires disclosure and enablement. An undisclosed feature may be inferred only where it is an inevitable consequence of performing the prior art. Obviousness depends on the prior art and the skilled person’s common general knowledge, with secondary evidence serving only as an aid. A claim introduces added matter only if it gives the skilled person new technical information.

Edwards sought revocation of Boston’s European patents 2 749 254 and 2 926 766, both concerning repositionable transcatheter heart valves. Boston counterclaimed for infringement by Edwards’ Sapien 3 valve.

The issues included construction of claims concerning a fabric seal, bunching and sacs; infringement; novelty and inventive step over four items of prior art; insufficiency; and added matter. The central questions were whether the claimed sealing arrangements were disclosed or suggested by the prior art, and whether the Sapien 3 fell within the claims.

1. Skilled team and common general knowledge. The skilled team comprised an interventional cardiologist and a biomedical engineer. A cardiac surgeon was not included because cardiac surgeons with practical TAVI experience were not shown to form part of the relevant skilled team at the priority date. Paravalvular leakage was known as a problem, although not generally regarded as a likely significant cause of mortality.
2. Construction. The claims were construed purposively. In the context of divisional patents, the skilled reader would recognise that embodiments might combine more than one invention. Knowledge of the divisional origin did not create rigid assumptions or hidden limitations. “Bunched up” required excess fabric capable of forming folds and providing a significant sealing effect. A sac comprised a cavity and its fabric walls; its inner wall could be inside or outside the anchor provided the sac functioned as a seal.
3. Infringement. The Sapien 3 had a bunched-up fabric seal and at least one sac within the meanings of the claims. It infringed claim 1 and certain dependent claims of the 254 Patent, and claim 1 of the 766 Patent. It did not infringe claim 3 of the 254 Patent.
4. Novelty. Prior art must disclose the invention and enable the skilled person to perform it. An integer may be disclosed by inference, but only where the inference is inevitable. Neither Cribier nor Bessler inevitably disclosed the claimed bunched-up sealing arrangement, and neither disclosed the sac required by the 766 Patent.
5. Inventive step. The 254 Patent was obvious over Thornton. The skilled team would have regarded Thornton’s flange seal as a related and promising teaching, with a reasonable expectation that it would reduce paravalvular leakage. The 254 Patent was not obvious over Cribier or Bessler. The 766 Patent was not obvious over Cribier, Bessler, Thornton or Seguin because the additional two-walled sac was not suggested.
6. Other validity attacks. Neither insufficiency nor added matter was established. A broader claim does not add matter merely because the application describes a narrower embodiment, provided the broader claim gives no new technical information.
7. Disposition. The 254 Patent was invalid for lack of inventive step, but would have been infringed. The 766 Patent was valid and infringed.

First-instance decision in the Patents Court. No appellate history was stated in the judgment.