Abbott Diabetes v Dexcom [2023] EWHC 2591 (Ch)

18 October 2023

Daniel Alexander KC, James Whyte and Jennifer Dixon appeared for the claimant (“Abbott”) against the defendant (“Dexcom”), in the third trial in a series of patent infringement trials concerning continuous glucose monitoring (“CGM”) systems. Dexcom sought to revoke Abbott’s patent (the “Patent”) on grounds of: (i) added matter; (ii) insufficiency; (iii) anticipation; and (iv) obviousness.

The Patent was for an ‘inserter’: a device used for inserting a sensor under a CGM system user’s skin. The sensor would then be capable of being attached to electronic apparatus so the user, typically with diabetes, could monitor their blood glucose. The allegedly infringing device was Dexcom’s rival inserter (the “G7 Applicator”).

Richards J found that the G7 Applicator did not infringe the Patent. This followed his findings in ten disputed points of construction, relating to claim 1 of the Patent, with points decided in each party’s favour.

On added matter, the judge held that whilst the Patent claim in issue was written in more general terms than Abbott’s earlier PCT application, this did not amount to new teaching and was therefore not an intermediate generalisation. Dexcom’s insufficiency argument was also rejected: the aspects of the claim which were broader than the disclosure in the Patent were a simple application of the common general knowledge.

Dexcom decided to advance its arguments on prior art (anticipation and obviousness) as ‘squeeze’ arguments, thereby accepting (in UK proceedings) that if the G7 Applicator was found not to infringe, then the Patent would not be invalid in light of the prior art. Therefore, in light of his previous findings, Richards J upheld the validity of the Patent.

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