The company said that the second interim analysis of its phase 2b/3 study in 40,000 subjects demonstrated interim vaccine efficacy of 47% against COVID-19 of any severity. It noted that at least 13 variations of the disease were circulating within the study population.
"While we were hoping for a stronger interim outcome, we recognize that demonstrating high efficacy in this unprecedented broad diversity of variants is challenging,” said Dr. Franz-Werner Haas, CEO of CureVac in a statement. “As we are continuing toward the final analysis with a minimum of 80 additional cases, the overall vaccine efficacy may change,” he said. "In addition, the variant-rich environment underlines the importance of developing next-generation vaccines as new virus variants continue to emerge."
Shares of CureVac lost half their value in after-hours trading, following the statement. Shares fell $47.54, or 50%, to $47.25 in after-hours trading. The stock fell 3.5% in the regular session.
Hass told the New York Times that the company still plans to seek approval for the vaccine from the European Medicines Agency. The EU agreed to buy more than 400 million doses of the vaccine if the agency authorizes it.
In February, CureVac announced a deal with GlaxoSmithKline (GSK) - Get Report to develop COVID vaccines. Glaxo holds a 10% stake in CureVac. American Depositary Receipts of GlaxoSmithKline edged lower in after-hours trading.
CureVac came public in an IPO last August, raising more than $200 million to fund its research and development efforts.