Akebia Therapeutics Inc v Fibrogen, Inc & Astellas [2020] EWHC 866 (Pat)
A multi-patent action concerning the use of an enzyme inhibitor to treat anaemia and related conditions. The patents in issue fell into two families – Family A & Family B – and included claims to classes of compounds and to single compounds.
Akebia sought revocation of the patents to clear the way for launch of its pharmaceutical product. The grounds for revocation included insufficiency and obviousness.
Fibrogen was the patentee and Astellas its exclusive licensee. Astellas counter-sued for infringement, alleging both literal infringement and infringement by equivalents.
Arnold LJ, who came down from the Court of Appeal to hear the case at first instance, held that the Family A patents involved inventive step but, to the extent that they covered classes of compounds, were insufficient. The Family B patents were obvious. He further held that certain claims of the Family A patents were infringed on a literal basis, but dismissed the infringement claim based on equivalence to the single compound. There was insufficient threat of infringement of the Family B patents.
Permission to appeal has been granted in respect of the findings of invalidity.
Points of interest include the Judge’s comments on the utility of primers, the instruction and cross examination of expert witnesses, infringement by equivalence and how to assess a threat of infringement based on the likelihood of future ‘off label’ prescribing
Iain Purvis QC, Piers Acland QC and Anna Edwards-Stuart represented Akebia. Kathryn Pickard represented Astellas