Health care stocks were falling pre-bell Monday, with The Health Care Select Sector SPDR Fund (XLV) down 0.6% and the iShares Biotechnology ETF (IBB) 1.1% lower.

Regeneron Pharmaceuticals (REGN) shares were down 0.9% after the company said late Friday that the US Food and Drug Administration issued a complete response letter rejecting its request to add extended dosing intervals for Eylea HD injection 8 mg across all approved indications.