08:53 AM EDT, 05/23/2025 (MT Newswires) -- Health care stocks were flat to lower pre-bell Friday, with the iShares Biotechnology ETF (IBB) inactive and The Health Care Select Sector SPDR Fund (XLV) down 0.2%.

Merus (MRUS) shares were up over 14% after the company said interim data from a phase 2 trial of the bispecific antibody petosemtamab in combination with pembrolizumab showed "robust" efficacy and durability as a first-line treatment of PD-L1+ recurrent/metastatic head and neck squamous cell carcinoma.