Moderna announced that it has completed enrollment of 30,000 participants in the phase 3 COVE study of its investigational coronavirus vaccine mRNA-1273. More than 25,650 participants have so far received their second dose, and Moderna said it will decide whether to seek emergency-use authorization based on an assessment of the vaccine’s benefit-risk profile, which will be conducted once it has accrued 2 months of median safety follow-up data.
CEO Stéphane Bancel recently indicated that the US could authorize emergency use of mRNA-1273 in December, having previously suggested Moderna would likely be able to determine by next month whether the vaccine candidate works. The company said a formal efficacy analysis of the COVE study will be triggered at 151 cases of SARS-CoV-2 infection, although two earlier interim analyses will done as well, after 53 and 106 cases.
“Completing enrollment of the phase 3 COVE study is an important milestone for the clinical development of mRNA-1273,” commented Bancel, adding the drugmaker “will continue to work in collaboration with regulators to advance mRNA-1273.”
The randomized study, conducted in partnership with the US National Institute of Allergy and Infectious Diseases, is testing mRNA-1273 at the 100-mcg dose level against placebo, and is designed to evaluate Americans at the highest risk of severe COVID-19 disease, according to Moderna. The company noted that so far, the trial includes more than 7000 volunteers over the age of 65. It also has more than 5000 participants under 65 with chronic diseases that put them at greater risk for severe COVID-19, such as diabetes, severe obesity and cardiac disease. These medically high-risk groups represent 42% of the COVE study population. Moderna also highlighted that the trial’s make-up is “similar to the diversity of the US at large,” and includes more than 6000 Hispanic participants and over 3000 African Americans.
Early phase 1 data published in the NEJM in July demonstrated that a two-dose vaccination schedule of mRNA-1273 induced anti–SARS-CoV-2 immune responses in all 45 healthy volunteers, who ranged in age from 18 to 55 years. More recent findings, also reported in the NEJM, showed that the vaccine was well tolerated and generated strong immune responses in older adult and elderly participants as well.