DSM IP Assets BV & Anor v Algal Omega 3 Limited (In Administration) & Anor

In a patent appeal, obviousness is a multi-factorial assessment and appellate intervention is confined to an error of law or principle. The appellate court must avoid hindsight: a post hoc sequence of routine steps leading from prior art to the invention does not establish that the skilled team would have taken that route at the relevant date.

Patent claims receive a purposive, contextual construction. Purpose informs meaning but cannot displace the claim language or deprive a deliberate limitation of effect. A process claim may be defined partly by its result. A limitation referring to ‘the lipid’ may therefore concern the lipid obtained after the process, rather than impose the same requirement at every intermediate stage.

DSM alleged infringement of three patents concerning microbial oils and their production. At trial, Mellor J held EP155 valid, EP740 invalid, and EP801 invalid for obviousness, although certain processes would have infringed EP801 if valid. The appeals arose from the order of 18 June 2025 and the reasons dated 20 March 2025, cited in the judgment as [2025] EWHC 625 (Pat).

Mara appealed the finding that EP155 was valid. DSM appealed the finding that EP801 was obvious and argued that further processes would infringe if the patent were valid. The central issues were whether the judge had erred in assessing obviousness over Bijl and Kobzeff, and whether the limitation concerning less than 5% organic solvent referred to the resulting lipid or to lipid throughout the process. A further pH construction issue was contingent on DSM succeeding on both EP801 grounds.

Arnold LJ gave the principal judgment. Miles and Moylan LJJ agreed.

1. Disposition. Both appeals were dismissed. Mara’s challenge to EP155 validity failed. DSM’s challenge to EP801 obviousness failed. Mara’s respondent’s notice based on Hendrik did not arise once its EP155 appeal failed. The Court abstained from deciding the contingent issue concerning the meaning of pH 8 or above.
2. EP155 and obviousness. Obviousness involves a multi-factorial evaluation. Appellate intervention is permitted only for an error of law or principle, as stated in Actavis Group PTC EHF v ICOS Corp [2019] UKSC 15, Lifestyle Equities CV v Amazon UK Services Ltd [2024] UKSC 8 and Iconix Luxembourg Holdings SARL v Dream Pairs Europe Inc [2025] UKSC 25. The judge was entitled to conclude that claim 1 of EP155 was not obvious over Bijl. Mara’s case used Bijl principally as a hook for the common general knowledge of enzymatic lysis, discarded much of Bijl’s teaching, required selection of an unmentioned Schizochytrium strain, and depended on a hindsight-driven sequence of steps. The evidence did not establish that the skilled team would infer that enzymatic lysis produced an easier-to-break emulsion.
3. EP801 construction. The phrase less than 5% by weight of an organic solvent referred to the lipid resulting from the claimed process. The words ‘the lipid’ referred back to the lipid identified in the opening clause and in step (d). A process claim may be defined partly by its result. Requiring the limitation at every intermediate stage would make little sense in the context of an emulsified cell composition. Purpose was relevant but not conclusive, and the specification distinguished processes from the lipids obtained by them. This followed the purposive, contextual approach under the European Patent Convention and Virgin Atlantic Airways v Premium Aircraft Interiors [2009] EWCA Civ 1062.
4. EP801 obviousness. Even on DSM’s construction, the judge was entitled to hold the claim obvious over Kobzeff. Kobzeff disclosed all relevant elements except the pH of 8 or above, and the finding that this pH would be obvious with a protease enzyme was unchallenged. The judge was entitled to accept the evidence that salt or heating could be used without a polar organic solvent. A sufficient expectation of success was implicit in the judge’s reasoning and common-general-knowledge findings. The assessment was not a hindsight-driven, stepwise reconstruction.

• Court of Appeal (Civil Division): In [2026] EWCA Civ 136, both appeals were dismissed. The contingent pH construction issue was not decided.
• High Court of Justice, Patents Court: Mellor J’s decision, cited in the judgment as [2025] EWHC 625 (Pat), held EP155 valid, EP740 invalid, and EP801 invalid for obviousness, while finding that some processes would have infringed EP801 if valid.