Massachusetts-based Moderna has published interim data from the Phase I study of its Covid-19 vaccine, mRNA-1273. The Phase I trial is being coordinated by the US NIAID and involves three dosing groups: 25 µg, 100 µg and 250 µg - the first two groups were dosed twice, while the third was only dosed once.
All participants across the three doses seroconverted by day 15 after a single dose. At day 43 two weeks after the second dose, 25 µg group's levels of binding antibodies were the same as those seen in blood samples of recovered Covid-19 patient,s while the 100 µg group's levels of binding antibodies significantly exceeded those found in recovered patients.
mRNA-1273 was found to be generally well tolerated and safe; this is particularly important as vaccines are administered to healthy people.
Moderna chief medical officer Tal Zaks commented: “These interim Phase I data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response of the magnitude caused by natural infection starting with a dose as low as 25 µg.
"These data substantiate our belief that mRNA-1273 has the potential to prevent COVID-19 disease and advance our ability to select a dose for pivotal trials.”
The company's CEO Stéphane Bancel added: “With today’s positive interim Phase I data and the positive data in the mouse challenge model, the Moderna team continues to focus on moving as fast as safely possible to start our pivotal Phase III study in July and, if successful, file a BLA."
Moderna's Phase II study design was approved by the FDA in early May.