Abbott Diabetes Care Inc & Ors v Dexcom Inc & Ors

For novelty under the Patents Act 1977, a prior-art document must disclose the claimed invention in a way that is enabling. Where disclosure is implicit, the claimed invention must necessarily follow; it is insufficient that the document makes the invention merely possible or obvious.

Patent claims must be construed purposively through the eyes of the skilled person, read as a whole and in context. Broad language should not be artificially narrowed, and specific exhaustive language should not be expanded. A claim requiring indications arising during a routine requires the indications to be caused by something distinct from that routine. Expert evidence assists construction but cannot replace the court’s legal judgment.

Abbott appealed from the High Court’s decision that four patents concerning continuous glucose monitoring technology were invalid. The appeal concerned only the revocation of EP 627 and EP 223 for lack of novelty. The respondents did not oppose the appeal after the wider dispute had settled, and the Comptroller-General assisted the court.

EP 627 concerned notifications generated during a predetermined routine. EP 223 concerned checks on a safety-critical application operating on an uncontrolled data processing device. The central questions were whether the prior art disclosed the claimed features, including implicitly, and whether the trial judge had applied the correct standard for anticipation.

Appeal allowed in part. The Chancellor delivered the judgment, with Stuart-Smith LJ and Miles LJ agreeing.

1. Under section 125(1) of the Patents Act 1977, claims are construed through the eyes of the skilled person, using the description and drawings. The approach is purposive, contextual and directed to the language used, while reading the patent as a whole. General non-exhaustive language should not be artificially read down, and specific exhaustive language should not be read up. The court applied Actavis v Eli Lilly [2017] UKSC 48, Saab Seaeye v Atlas Elektronik [2017] EWCA Civ 2175, Nokia v IPCom [2009] EWHC 3482 (Pat) and Fisher and Paykel Healthcare Ltd v Flexicare Medical Ltd [2020] EWHC 3282 (Pat).
2. Under sections 1(1) and 2 of the Patents Act 1977, anticipation requires an enabling disclosure. Disclosure requires clear and unmistakeable directions to do something within the claim, and enablement requires that the skilled person could perform the invention using the disclosed matter and common general knowledge. For implicit disclosure, the invention must necessarily follow. Possibility or obviousness is insufficient for novelty, although it may be relevant to inventive step under section 3.
3. For EP 627, the three-day sensor-expiry countdown was not a predetermined routine within the claim. The claim presupposed that the indications were caused by something distinct from the routine and capable of interrupting it. The process interfacing with the user interface under integer 1.9 also had to be distinct from the indications required by integers 1.3 and 1.4. The STS Guide therefore did not anticipate the claim.
4. The two STS Guide notifications also related to distinct conditions: the 30-minute notification concerned the time remaining before expiry, whereas the 0-hour notification concerned actual expiry. They were not indications associated with the same predefined alarm condition.
5. For EP 223, the expression safety critical application was broadly drawn. It contained no requirement of direct causation of harm, exclusive reliance by the user, or use in isolation. A healthcare database could therefore fall within the expression. The Gejdos database integrity check was capable of satisfying both the installation and functional checking requirements, and the claim did not require direct checking of every aspect or component.
6. Gejdos did not, however, establish selective enablement. Its express disclosure was only an error message. The expert evidence that the skilled person would understand this to include disabling database-related functions did not demonstrate that the claimed selective enablement necessarily followed. The finding of anticipation on that ground could not stand.
7. The appellate court ordinarily defers to factual or evaluative findings unless there is a clear error of approach or the conclusion is rationally insupportable. The exceptional delay in producing the High Court judgment required the findings to be reviewed with special care.

The appeal was allowed on EP 627 grounds 1(a) and 1(b), and on EP 223 ground 3. It was dismissed on EP 223 grounds 1 and 2.

1. Court of Appeal (Civil Division): [2025] EWCA Civ 1687. Appeal allowed in part.
2. High Court of Justice, Patents Court: After a six-day trial in November and December 2022, Mellor J delivered judgment on 15 January 2024 holding all four patents invalid. A consequential order followed on 13 January 2025. Permission to appeal in relation to EP 627 and EP 223 was granted by Arnold LJ on 25 March 2025.