Moderna Inc said there was a possibility it was not the first company to make breakthroughs claimed in its patent applications, including those for its experimental coronavirus vaccine, according to a recent regulatory filing.

The statement by the US drug developer was made in a quarterly filing on Aug. 6 under mandatory disclosures of risks to its business.

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Moderna’s prior quarterly filings with US regulators did not have the disclosure.

“For this and other reasons, we may be unable to secure desired patent rights, thereby losing exclusivity,” the company said.

The company has received funding from the US government to develop its coronavirus vaccine, and in July lost a bid to invalidate a US patent owned by Arbutus Biopharma Corp that poses a potential obstacle to Moderna’s efforts to develop next-generation vaccines.

“We cannot be certain that we were the first to make the inventions claimed in our patents or pending patent applications, or that we were the first to file for patent protection of such inventions, including mRNA-1273,” the company said.