Moderna has been forced to halt an early-stage clinical trial for its mRNA Epstein-Barr virus vaccine in adolescents.
Investigators stopped the trial after one of the participants developed a suspected case of myocarditis.
According to Unreported Truths: The case “necessitates an immediate suspension of all dosing for ALL adolescents,” an investigator at the company that is supervising the trial for Moderna wrote, adding, “Please confirm understanding and receipt of this urgent communication.”
The trial subjects should continue to be monitored for safety, the investigator wrote. About 150 adolescents are in the trial, along with 272 people aged 18-30.
A person not employed by Moderna, which makes the Spikevax Covid vaccine, provided the email to Unreported Truths.
Moderna did not disclose the trial halt, which occurred before stock markets opened for trading Thursday, to investors. Moderna stock is down about 85 percent from its highs in 2021, as sales of Spikevax lag, but it remains among the most valuable biotechnology companies, with a $30 billion market value.
(All Dosing Must Pause Immediately! A partial subject line from the email sent halting the trial. Note the email time stamp – before Moderna stock opened for trading Thursday.)
The Epstein-Barr virus, which causes mononucleosis, is one of Moderna’s leading candidates for new vaccines. The company has told investors it could reach billions of dollars in sales a year.
But the trial halt raises questions for Moderna and mRNA jabs that go far beyond the Epstein-Barr vaccine – officially called mRNA-1189 – alone.
The vaccine uses essentially the same design as Moderna’s Covid shot. Both jabs include a strand of modified mRNA surrounded by a tiny fat globule called a “lipid nanoparticle,” or LNP.