Court of Appeal for England and Wales Issues Important Ruling on Disgorgement of Profits

The decision, which I just became aware of today though it was released on July 27, is Lufthansa Technik AG v. Astronics Advanced Electronic Systems, [2026] EWCA Civ 964.  The principal opinion is by Lord Justice Arnold, in which Lord Justices Lewison and Nugee concur.  Lord Justice Lewison also writes a separate opinion, in which Lord Justice Nugee concurs, and Lord Justice adds a very short separate opinion of his own.  The decision is long (92 pages altogether, with 353 paragraphs), and while the principal topic is the principles applicable to awards of infringers’ profits (including the relevance of noninfringing alternatives, but-for and proximate causation, and apportionment), the case also presents issues relating to double recovery and prejudgment interest.  Lord Justice Arnold’s opinion cites some of my work, as well as work by Professor Norman Siebrasse and a chapter I coauthored (with Siebrasse, Chris Seaman, Brian Love, and Masabumi Suzuki) that was published in the edited volume Patent Remedies and Complex Products (Cambridge Univ. Press 2019). Rather than rush to get something out, I want to do justice to this important and thoughtful decision, and I suspect that doing so may require two or three separate, rather detailed, blog posts.  For today, then, I’m simply providing the link to the decision (above) for readers who have not read it yet but are interested in the relevant topics, and will summarize what I view as the three most important holdings, all pertaining to disgorgement of profits.  The first is that “there are some cases in which it is possible to say that all of the profits in issue are derived from the infringement” (para. 159).  The second is that a “differential profits analysis”—under which the profits attributable to the infringement are measured by the difference between the profits the infringer actually earned and the amount if would have earned in the counterfactual world in which it deployed the next-best available noninfringing alternative to the patented invention—can in some cases be “a useful tool to identify the profits derived from the infringement” (para. 160), but that there are numerous difficulties concerning its use in the real world (see paras. 150-58).  The third is that “there is a well-established alternative to differential profit analysis, which is for the court to make a fair apportionment of the profits in issue,” and that “[t]his approach is to be adopted when the case does not fall into either of the [preceding] two categories . . . that is to say, it is not a case where all of the profits are derived from the infringement or where a differential profit analysis can readily be undertaken” (para. 161; see also para. 111, describing apportionment as "normally the appropriate approach").  The opinion then goes on (starting at paragraph 191) to discuss some principles relating to how apportionment may be carried out.

Again, this is a very important decision on one of the most practically and intellectually challenging topics in all of IP remedies law.  My plan is to return with a detailed, probably multipart, analysis, probably starting the week after next (I will be away for one more little summer jaunt next week).