Invivyd (IVVD) said Monday that the US Food and Drug Administration rejected its request to expand the existing emergency use authorization for Pemgarda to include treatment of mild-to-moderate Covid-19 in immunocompromised adults and adolescents.

The drug, also called pemivibart, is already being used as a preventative measure for some immunocompromised patients who are not currently sick with Covid-19, the company said.

Invivyd said its application for pemivibart as a Covid-19 treatment option was not considered in its current financial guidance and that it plans to publicly share detailed data and regulatory correspondence regarding pemivibart in comparison with other drugs.

Shares of the company were down more than 34% in recent premarket activity.