In reviewing clinical trial data related to the Novavax (Nasdaq:NVAX) COVID-19 vaccine, FDA expressed concerns about the product’s potential to cause myocarditis, a type of heart inflammation.
In a briefing document, FDA noted that the “identification of multiple potential vaccine-associated cases in a premarket safety database of ~40,000 vaccine recipients raises concern.” The agency goes on to say that if causally associated, “the risk of myocarditis following NVX-CoV2373 could be higher than reported during post-authorization use of mRNA COVID-19 vaccines (for which no cases were identified in pre-authorization evaluation).”
In a statement, Novavax concluded that the rate of myocarditis and a similar condition known as pericarditis was similar across vaccine and placebo recipients. In the vaccine arm, 0.007% experienced such heart inflammation, while 0.005% of placebo recipients did.
Myocarditis is a risk occasionally associated with mRNA COVID-19 vaccines. A JAMA report noted that the risk of myocarditis was most common in adolescent males and young men.
A separate JAMA report estimated fewer than 30 cases of myocarditis per 100,000 mRNA vaccine recipients in Nordic countries.
NVAX shares dipped 14% on Friday but were up 7.55% to $48.14 in afternoon trading today.
The Novavax vaccine had an efficacy rate of 90.4% in the pivotal trial conducted in the U.S. and Mexico.
FDA plans on holding a VRBPAC meeting on June 7 to discuss granting emergency use authorization for the Novavax vaccine.