Moderna’s stock rose after the Board of Appeal of the European Patent Office revoked a patent held by Arbutus Biopharma. Moderna (MRNA) shares added approximately 4% in premarket trading following the news, while Arbutus Biopharma (ABUS) shares fell significantly.

The revoked patent was central to an ongoing legal dispute concerning Moderna’s COVID-19 vaccine technology.

The ruling is expected to impact related patent infringement cases. Arbutus and its partner, Genevant Sciences, brought these suits against Moderna in Switzerland and the Unified Patent Court.