Arbutus Biopharma and Genevant Sciences have filed a complaint in federal court charging Moderna with infringing on patents related to their messenger-RNA (mRNA) delivery technology used in Moderna’s COVID-19 vaccine.

In their suit filed Monday in the U.S. District Court for the District of Delaware, Arbutus and Genevant said they are not seeking to “impede the sale, manufacture or distribution” of Moderna’s mRNA-based shot, but are just seeking damages.

In December, a federal appeals court paved the way for Arbutus and Genevant to file a lawsuit by striking down Moderna’s challenge of their lipid nanoparticle technology allegedly used in the production of Moderna’s COVID-19 shot.

The Cambridge, Mass., drugmaker earned $18.5 billion in total revenue for 2021, almost all of which was from sales of its coronavirus vaccine.