Moderna reported this week that its investigational influenza vaccine, mRNA-1010, demonstrated an acceptable safety and tolerability profile across all clinical trials to date, including 3 phase 3 trials (P301, P302, P303).
The company also said that enrollment is now complete for its phase 3 safety and immunogenicity trial for the updated formulation of mRNA-1010 (P303). In an interim analysis of the P303 study, the vaccine met all coprimary endpoints across all 4 A and B strains, including, A/H1N1, A/H3N2, influenza B/Yamagata, B/Victoria.
Higher HAI geometric mean titers and seroconversion rates were observed for all four strains compared to a licensed comparator (Fluarix).
In terms of safety, Moderna reported local and systemic solicited adverse reactions were similar to those reported in previous mRNA-1010 studies. Independent data and safety monitoring boards have raised no safety concerns.
Improved immunogenicity was observed across age groups. mRNA-1010 also elicited higher HAI titers against A/H1N1, A/H3N2, B/Victoria, and comparable titers to B/Yamagata compared to Fluzone HD in a separate phase 1/2 head-to-head study.
The company noted that the previous P302 phase 3 efficacy study has not accrued its target case numbers by the end of the most recent season and that enrolling a second season would be required to do so. According to the statement, the news that the P303 trial met all its primary endpoints has precluded any further enrollment in the P302 study.
Highlighting the announcements made on September 13th, the Moderna annual R &D day, is the company’s plan to continue development of influenza vaccine candidates that include additional HA antigens for broader coverage of circulating influenza A strains (mRNA-1011 and mRNA-1012) and candidates that incorporate both HA and neuraminidase (NA) antigens to target multiple proteins involved in the influenza virus lifecycle to reduce the potential of viral antigenic escape (mRNA-1020 and mRNA-1030).
The company also provided an update on many of their other later stage vaccine products.
"Our mRNA platform is working. With today's positive phase 3 flu results, along with previous results in COVID and RSV, we are now 3 for 3 on advancing respiratory disease programs to positive phase 3 data," Moderna CEO Stéphane Bancel, said in statement.
In the spring, the company reported data on the 1010 vaccine, and it showed the mRNA flu vaccine was not statistically noninferior against 2 influenza B strains. Moderna noted at that time its preliminary analyses proved the vaccine generated robust immune responses, but investigators could not determine whether the candidate was statistically noninferior to existing approved vaccines.
“With mRNA-1010, our first investigational vaccine against seasonal flu, we are encouraged by the consistently strong immunogenicity results against influenza A, and titers consistent with noninferiority against influenza B strains in the most recent phase 3 trial,” stated Bancel at that time.
However, with today’s findings, the vaccine appears ready for an FDA submission. In fact, consultations with regulators on a potential licensing package are currently ongoing based on these data. The company expects an April 2024 PDUFA date, which would make it possibly available for next year’s influenza season.