Sometimes patent law is about procedures and not inventions. The appeal in T 1168/24 related to the lipid nanoparticle (LNP) technology behind the COVID-19 vaccines, opposed by Merck and Moderna. After two rounds of opposition and two appeals, the patent was revoked for added matter. Whilst the global litigation surrounding LNPs is interesting in its own right, this case also raises some interesting legal issues surrounding the principle by which an appellant should not be put in a worse position by their own appeal ( reformatio in peius ). The Board of Appeal found that this principle continues to bind a Patentee who withdraws their appeal, even in cases where an opposition division (OD) decision is set aside for a violation of the right to be heard. The Patentee was left defending a narrow claim with an added matter problem which it could not then fix with a broadening amendment. Vaccine formulations The commercial stakes were high in this case. The patent ( EP 2279254 ) was one...