FDA agrees to review Moderna’s mRNA flu vaccine application in a reversal

Moderna said on Wednesday the Food and Drug Administration has agreed to review its experimental mRNA flu shot, reversing the agency’s earlier decision to refuse to accept the application in a move that stunned Wall Street and the medical community. 

The announcement clears a path forward for the vaccine, which is key to Moderna’s experimental combination Covid-flu jab and the company’s goal of breaking even by 2028. The FDA is slated to make a decision on the flu shot on Aug. 5, which will allow Moderna to make the vaccine available for the upcoming influenza season. 

“Pending FDA approval, we look forward to making our flu vaccine available later this year so that America’s seniors have access to a new option to protect themselves against flu,” said Moderna CEO Stéphane Bancel in a release. 

Shares of the biotech company rose more than 6% on Wednesday.

Moderna said it had a “constructive” meeting with the FDA and proposed a revised regulatory approach that addresses criticisms the agency made when refusing to accept the application last week, tailoring its new proposal to an older population.

Under the new approach, Moderna is seeking full approval for the shot in adults ages 50 to 64 and an accelerated approval of the shot for people 65 and up. The latter means that upon approval, Moderna will have to conduct an additional post-marketing study in older adults to confirm its benefits. 

In a statement, Health and Human Services spokesperson Andrew Nixon confirmed that the FDA has accepted the modified application.

The agency specifically took issue with Moderna’s decision to compare its product to a standard, approved flu shot in a phase three trial, arguing that it “does not reflect the best-available standard of care” in the U.S. The FDA’s previous feedback expressed a preference for Moderna to use a higher-dose vaccine for older adults as a comparator in the trial.

In an interview with CNBC on Wednesday before the announcement, FDA Commissioner Dr. Marty Makary did not indicate that the agency would reverse course. But he emphasized that the FDA reviewed the application and the initial late-stage trial on the shot when it came in, so “it’s a little bit of a misnomer to say that it was not looked at.”

Makary said the agency’s guidance to Moderna on its mRNA-based flu shot “was pretty clear.” He said the FDA recommended that the group of participants ages 65 and up in the study who didn’t take Moderna’s shot receive the “standard of care, not the substandard of care” as a comparison product. 

Moderna has disputed that reasoning, noting that FDA rules and guidance do not actually require trials to use the most advanced or highest-dose vaccine as a comparator in clinical studies. The company also said it was inconsistent with the FDA’s prior written communication about the trial design, even before the study began, where the agency said using the standard flu shot would be “acceptable.”

The saga follows sweeping changes to U.S. immunization policy and regulation over the past year under Health and Human Services Secretary Robert F. Kennedy Jr., a prominent vaccine skeptic. 

Moderna last week said the decision specifically stemmed from the FDA’s top vaccine regulator, Vinay Prasad, who returned to the agency in August after being ousted. Prasad, who heads the agency’s Center for Biologics Evaluation and Research has been vocal about tightening regulations for vaccines and recently linked child deaths to Covid shots without evidence.

Last week, Moderna released a so-called Refusal to File letter from the FDA that was signed by Prasad on Feb. 3. HHS does not typically share those letters, and has not provided any details on who drove the decision-making on the company’s application.

When asked about his stance on mRNA technology, which Kennedy and some of his supporters have criticized as unsafe, Makary told CNBC on Wednesday that he’s “hopeful and optimistic” about the platform but would also “like to see the data.”

“We’re not going to get ahead of the game,” he said. “We’re going to basically say, we’d like to see the data, how far mRNA technology can be applied is a question where we’d love to see it applied, as far as it can be applied, but it’s got to meet our scientific standards, so we’ll see what it gets with cancer, with other infectious diseases …”