Illumina Cambridge Limited v Latvia MGI Tech Sia

In patent appeals, an appellate court should not disturb a specialist judge’s multi-factorial assessment of obviousness absent an error of law or principle. Prior art must be assessed without hindsight. A neighbouring-field disclosure of a chemical intermediate does not make a sequencing use obvious merely because routine tests could be performed, where there is no reasonable prospect of success. Priority requires direct and unambiguous disclosure and enablement. In predictive claims, plausible support may be required, although the universal scope of that requirement was left unresolved. A molecule composed of individually obvious parts is not necessarily a mere collocation where the parts may interact unpredictably and demonstrated non-interference forms part of the technical contribution.

Illumina owned four patents concerning sequencing by synthesis: three modified-nucleotide patents and a patent concerning dye compounds and labelled conjugates. Birss J held the patents in issue valid and infringed, while revoking a fifth patent; his judgment is reported at [2021] EWHC 57 (Pat).

MGI appealed on obviousness over Zavgorodny, entitlement to priority from an earlier application, and whether the dye patent claimed only a collocation of obvious features. The Court of Appeal considered those issues and whether the trial judge’s findings disclosed any legal or principled error.

Arnold LJ gave the leading judgment, with which Nugee LJ and Warby LJ agreed. The appeal was dismissed in relation to both patent groups.

1. Obviousness. The assessment of obviousness is multi-factorial. An appellate court should not intervene without an error of law or principle, particularly where an experienced specialist patents judge has evaluated extensive expert evidence, applying the approach in Actavis Group PTC EHF v ICOS Corp [2019] UKSC 15. The skilled team must approach prior art without hindsight or an assumption that it addresses a problem identified only after the invention. Zavgorodny was concerned with synthetic intermediates, not sequencing by synthesis. Its disclosure of an azidomethyl protecting group did not give the skilled team a reason to use it as a reversible chain terminator. Routine testing did not establish a reasonable prospect of successful incorporation, deblocking, yield and speed. The modified-nucleotide claims were therefore not obvious.
2. Priority. Under the Patents Act 1977 and Article 87(1) EPC, the earlier application had to disclose the same invention directly and unambiguously and by an enabling disclosure. P2 gave materially more technical information than Zavgorodny: it proposed the claimed sequencing use and reported successful incorporation, efficient blocking and removal under neutral aqueous conditions. It was therefore plausible that the claimed compounds had the asserted utility. There was no inconsistency between non-obviousness over Zavgorodny and priority from P2. The Court did not decide whether plausibility is required in every priority case.
3. Collocation. The collocation principle requires the court first to decide whether the claim concerns one invention or several. Independent features performing their own functions separately may be assessed separately for obviousness. Here, however, the dye, linker and nucleotide formed a single molecule and could interact adversely in ways that could not be predicted without testing. The demonstrated absence of adverse interaction was part of the technical contribution. The claimed molecule was therefore a single invention, not a mere collocation, and the 415 Patent remained valid.

• Court of Appeal (Civil Division) dismissed MGI’s appeal and upheld the relevant orders.
• High Court, Patents Court Birss J held four patents valid and infringed, as amended, in [2021] EWHC 57 (Pat). A fifth patent was held invalid, but that decision was not appealed.