The European Patent Office (EPO) has declared an mRNA patent of the US biotech company Moderna invalid in a patent dispute with BioNTech, a German rival. Moderna announced on Tuesday that it plans to appeal the decision, which they disagree with.

BioNTech welcomed the decision and expressed its belief that Moderna’s patents did not meet the requirements for grant and should never have been granted. According to the EPO, a written decision on the matter will be published in coming weeks or months.

Moderna had sued BioNTech and its partner Pfizer because it believed that their Covid-19 vaccine violated patents that were registered before the pandemic. CureVac, a Tübingen rival, also filed a lawsuit against Biontech because he saw his patents infringed by BioNTech’s successful Covid-19 vaccine. However, both companies rejected these allegations and filed a countersuit.