Moderna's messenger RNA flu vaccine candidate has shown has shown positive results in a late-stage trial.

Shares of Moderna rose 5.15% in premarket trading.

The biotechnology company said Monday its seasonal influenza vaccine candidate, mRNA-1010, showed superior efficacy in a Phase 3 study that compared it with a licensed standard-dose seasonal flu vaccine in adults aged 50 years and older.

Moderna said mRNA-1010 achieved the most stringent superiority criterion prespecified in the study protocol, with a relative vaccine efficacy of 26.6% in the overall study population.

Subgroup analyses confirmed a consistently strong relative vaccine efficacy point estimate across age groups, risk factors and previous influenza vaccination status, it said. In participants aged 65 years and older, mRNA-1010 demonstrated a relative vaccine efficacy of 27.4%.

"The severity of this past flu season underscores the need for more effective vaccines," Moderna Chief Executive Stephane Bancel said.

"An mRNA-based flu vaccine has the potential advantage to more precisely match circulating strains, support rapid response in a future influenza pandemic, and pave the way for Covid-19 combination vaccines."

The study comes as Moderna faces a much different environment in the U.S. than when it was widely lauded for its development of a Covid-19 vaccine based on its mRNA technology. Scientists and drugmakers have been seeking new uses for the underlying mRNA technology but now find themselves in the crossfire as the Trump administration is changing rules on vaccines and looking critically at the technology.

Moderna plans to present data on mRNA-1010 at an upcoming medical conference and submit for peer-reviewed publication.

The company said it will engage with regulators on filing submissions for mRNA-1010.