Moderna Will File for Emergency Approval if COVID Vaccine is 70 Percent Effective

Moderna has said its COVID-19 vaccine must be at least 70 percent effective before it will file for an Emergency Use Authorization (EUA).

The threshold is higher than the FDA’s guidelines, which say that a vaccine must demonstrate at least 50 percent efficacy over a placebo to be considered for an EUA or approval (DID, July 1).

Moderna began a phase 3 study of its messenger RNA-based vaccine candidate, mRNA-1273, in July and, as of Sept. 16, had enrolled 25,296 participants. Just over 10,000 participants have already received a second dose of the vaccine.

According to the trial’s protocol, which was posted online yesterday, an interim analysis of the trial will be conducted when 53 cases of COVID-19 occur. Another analysis will be conducted at 106 cases if the first analysis does not meet the efficacy threshold, and the final analysis will occur at 151 cases.

The Massachusetts-based drugmaker said that it would consider an EUA if the vaccine shows between 70 and 90 percent efficacy vs. a placebo, and that the EUA would likely be targeted at healthcare workers and the elderly.

Moderna said it should know by November whether mRNA-1273 is effective, but it is unlikely to have supporting data in October, and it may not have the data until December if infection rates slow down. The timing is significant as President Trump has been predicting that a vaccine will be ready by October.

Pfizer, which also has a vaccine in phase 3 testing in partnership with BioNTech, has repeatedly said it should know by October if its vaccine works. Pfizer’s CEO Albert Bourla has said the company plans to file for an approval immediately after it has the necessary data.

Meanwhile AstraZeneca, which is slowly re-starting its phase 3 trial after a clinical hold, has indicated that it could submit its vaccine data for regulatory approval by the end of the year. The study, which has started up again in the UK, Brazil and India, is still on hold in the U.S. pending an investigation (DID, Sept. 17). — Jordan Williams