Moderna Inc said on Friday its formula used in developing a Covid-19 vaccine was not covered under patents owned by Arbutus Biopharma.
An administrative court run by the US Patent and Trademark Office on Thursday rejected Moderna's arguments to invalidate a US patent owned by Arbutus, sparking worries over its efforts to develop next-generation vaccines, including a coronavirus vaccine.
Moderna said the court's ruling relates to actions it took in response to "longstanding aggressive posture" taken by Arbutus against developers of nucleic acid-based therapeutics and began well before the development of mRNA-1273, its Covid-19 vaccine candidate.
Moderna shares were up slightly in extended trading, while Arbutus shares closed down 20% on Friday.