Moderna said Wednesday afternoon that its experimental vaccine for cytomegalovirus, a cause of disability in newborns, failed in a Phase 3 trial, a significant setback for a company already facing pressure from Wall Street and the federal government.

The CMV vaccine had been the company’s lead program prior to the Covid-19 pandemic. Leadership had repeatedly said it could bring in between $2 billion and $5 billion in peak annual sales. Analysts polled by Visible Alpha forecast peak sales of $1.6 billion for the product.

“It’s obviously disappointing,” said Stephen Hoge, Moderna’s president, in an interview.