Novavax (NVAX) shares tumbled 5.44% in pre-market trading on Wednesday, as investors reacted to news about the company's ongoing interactions with the U.S. Food and Drug Administration (FDA) regarding its product approval process.

According to a recent SEC filing, Novavax announced its intention to engage with the FDA to address a Post-Marketing Commitment (PMC) request. This development has raised concerns among investors about potential delays or complications in the approval process for the company's products.

Despite the market's negative reaction, Novavax maintains a positive outlook on its Biologics License Application (BLA). The company stated, "We believe that our BLA is approvable based on conversations with FDA, as of our PDUFA date on April 1 and through today." This assertion suggests that Novavax remains confident in ultimately obtaining FDA approval, although the timeline and potential additional requirements remain uncertain.