The long and winding journey of Moderna’s mRNA flu vaccine toward regulators has come one step closer with a phase 3 win over an approved competitor shot.
Moderna said its own vaccine, dubbed mRNA-1010, had achieved a relative vaccine efficacy (rVE) of 26.6% over a “licensed standard-dose seasonal influenza vaccine” in the study of 40,805 adults aged 50 years and older spread across 11 countries.
Strong efficacy was observed for each influenza strain contained in the vaccine, including A/H1N1, A/H3N2 and the B/Victoria lineages, which demonstrated rVE of 29.6%, 22.2% and 29.1%, respectively.
Moderna’s original version of the vaccine had struggled against B strains of the virus—a common problem for the first generation of mRNA vaccines that entered the clinic—but updates to the candidate had already allowed it to prove its worth against these strains in a separate phase 3 victory over GSK's Fluarix back in 2023.
The safety and tolerability of mRNA-1010 in this morning’s trial were consistent with the results from the 2023 study, Moderna explained in a June 30 release. Most of the solicited adverse reactions (SARs) were mild, according to the company, with injection site pain being the most common localized SAR, while fatigue, headache and myalgia were the most common systemic SARs reported.
The latest phase 3 win is a boost for Moderna’s attempts to create a flu/COVID combination vaccine. The company withdrew a filing for FDA approval for its combo candidate last month while it waited for the mRNA-1010 readout.
“Today's strong phase 3 efficacy results are a significant milestone in our effort to reduce the burden of influenza in older adults,” Moderna CEO Stéphane Bancel said in the release.
“The severity of this past flu season underscores the need for more effective vaccines,” Bancel added. “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.”
Following the phase 3 win back in 2023, Bancel told Fierce that Moderna could potentially launch mRNA-1010 as soon as 2024. But, in this morning’s release, the company didn’t set out a revised timeline for approval, only saying it will “engage with regulators on filing submissions.”
The FDA is implementing “radical” changes to how it signs off on new vaccines, with new vaccines now expected to undergo safety testing in placebo-controlled trials prior to licensure. However, on an earnings call last month, President Stephen Hoge, M.D., said it had been “business as usual” in terms of Moderna’s interactions with the agency, adding that the company continues to have “productive exchanges” across all of its ongoing file reviews.
Moderna was up nearly 5% in premarket trading early Monday morning before levelling out at around 3%.