Moderna’s Omicron-containing Bivalent Booster Candidate, mRNA-1273.214, Demonstrates Significantly Higher Neutralizing Antibody Response Against Omicron Subvariants BA.4/5 Compared to Currently Authorized Booster

Moderna, Inc., (NASDAQ:MRNA) a biotechnology company pioneering messenger RNA (mRNA) therapeutics and vaccines, today announced new clinical data on its bivalent Omicron (BA.1) booster candidate, mRNA-1273.214. One month after administration in previously vaccinated and boosted participants, a 50 µg booster dose of mRNA-1273.214 elicited significantly higher neutralizing antibody responses against the Omicron subvariants BA.4 and BA.5 compared to the currently authorized booster (mRNA-1273) regardless of prior infection status or age (adults over 18, greater or less than 65 years old).

Among participants without prior infection, bivalent mRNA-1273.214 resulted in significantly higher neutralizing titers against BA.4/5 compared to the currently authorized booster, with a geometric mean ratio of 1.69 (95% CI: 1.51-1.90)¹. One month after booster, BA.4/5 neutralizing titers were 776 (95% CI: 719, 838) for mRNA-1273.214 and 458 (95% CI: 421, 499) for the currently authorized booster. The BA.4/5 geometric mean fold rise (GMFR) from pre-booster levels was 6.3-fold (95% CI: 5.7, 6.9) for mRNA-1273.214 recipients, and 3.5-fold (95% CI: 3.2, 3.9) for mRNA-1273 recipients. Consistent results were demonstrated across subgroups, including in those age 65 and older. The complete data has been submitted for peer reviewed publication and shared with regulators.

“We are very pleased that our bivalent platform continues to demonstrate better performance than the current booster. Today’s update extends the remarkable performance of mRNA-1273.214, demonstrating significantly higher titers against all tested variants, including the BA.4/5 and BA.1 Omicron subvariants, and adds to the largest body of data confirming the superiority of a bivalent approach. This superior breadth and durability of immune response following a bivalent booster has now been shown in multiple Phase 2/3 studies involving thousands of participants,” said Stephane Bancel, Chief Executive Officer of Moderna. “We are working with regulators to advance two bivalent vaccine candidates, mRNA-1273.214 and mRNA-1273.222, based on different market preferences for Omicron subvariants, clinical data requirements, and urgency of starting fall booster campaigns for vulnerable populations.”

Today’s data add to results shared last month from the Company’s ongoing Phase 2/3 study in approximately 800 participants. Previous results showed a 50 µg booster dose of mRNA-1273.214 met all pre-specified primary endpoints and was generally well tolerated, with a reactogenicity and safety profile that was consistent with the currently authorized booster.

Moderna is advancing two bivalent candidates for the fall based on different market preferences for Omicron subvariants. The mRNA-1273.214 bivalent booster is the only candidate expected to have demonstrated significantly higher titers against the BA.4/5 strain in a clinical trial before the fall booster season, when compared to the currently authorized booster. The second bivalent booster candidate, mRNA 1273.222, is based on the BA.4/5 strain and is being developed consistent with recent FDA advice. Both bivalent candidates contain 25 µg of the currently authorized booster (mRNA-1273) and 25 µg of an Omicron subvariant.