The parties disputed the validity of K’s patented mouse. R said that the specification was insufficient to allow reproduction, and that it was therefore incomplete.
Held: The specification was insufficient, and the patents invalid. The issue of construction which divided the parties is the meaning of ‘in situ replacement’
Henry Carr J considered the rival arguments on construction before concluding: ‘In my judgment, in situ replacement means replacing ‘in the position of’. The phrase is apt to describe a positional replacement and this is how it is used in context. The human sequences are to be inserted in the original position of the mouse segments juxtaposed with the mouse constant regions. The skilled person would appreciate that the patentee is using this language to distinguish targeted replacement from random insertion into the genome. This includes the case where the relevant murine sequence is deleted, and also the case where it is moved to a different location and inactivated.
The word ‘replacement’ is used in the specification to describe both deletion and displacement/inactivation. The invention is concerned with the use of LTVECs and the MOA assay to enable the targeted insertion and detection of human variable V, D and J gene segments, in place of mouse variable V, D and J gene segments, whilst retaining the mouse constant segments. Given that inactivation was a well-known alternative to deletion at the priority date, I do not consider that it would make technical sense for the patentee to have excluded embodiments where the murine sequence had been moved to a different location and rendered inactive.’
Henry Carr J
 EWHC 87 (Pat)
England and Wales
Appeal from – Regeneron Pharmaceuticals, Inc v Kymab Ltd and Another CA 28-Mar-2018
The claimant R now appealed from a finding that its two patents involving transgenic mice were invalid. The ‘in situ replacement’ failed to comply.
Held: The appeal succeeded. . .
At PatC – Regeneron Pharmaceuticals, Inc v Kymab Ltd and Another CA 23-May-2018
Leave to appeal to Supreme Court refused. Other post judgment issues – form of order. . .
At PatC – Regeneron Pharmaceuticals Inc v Kymab Ltd SC 24-Jun-2020
SC Kymab Ltd (‘Kymab’) alleges that the relevant patents are invalid for insufficiency because they did not enable the ordinary skilled person to work the claimed invention across the breadth of the claims. The . .
These lists may be incomplete.
Updated: 20 May 2021; Ref: scu.566275