(Reuters) – Shares of Moderna (NASDAQ:) fell 4% on Wednesday after a U.S. judge issued an order that strengthened Arbutus’ arguments in a patent infringement lawsuit related to Moderna’s blockbuster COVID-19 vaccines.

In a so-called “claim construction order”, U.S. District Judge Mitchell Goldberg interpreted parts of the patents in ways that strengthened Arbutus’ case, rejecting Moderna’s proposed definitions.

The order is relevant in determining whether Moderna’s vaccines are covered by Arbutus’ patented technology.

Shares of Moderna fell 4.6% to $98.81, while Arbutus shares rose more than 15% to $2.91 in afternoon trading.

The lawsuit, which was filed in 2022, has Arbutus seeking damages for infringement of U.S. patents related to Moderna’s COVID-19 vaccine.

Arbutus said it developed the so-called lipid nanoparticles (LNP) that enclose the vaccine’s mRNA payload, the patents related to which were licensed to Genevant Sciences, a joint venture between Arbutus and Roivant Sciences (NASDAQ:) Ltd.

The technology is used to deliver RNA to target cells without being attacked by the body’s immune system.

A trial in the case is currently set to begin next April.