09:19 AM EDT, 05/15/2025 (MT Newswires) -- Health care stocks were mixed pre-bell Thursday, with The Health Care Select Sector SPDR Fund ( XLV ) marginally lower and the iShares Biotechnology ETF (IBB) up 0.5%.

UnitedHealth Group ( UNH ) is facing a criminal investigation by the US Department of Justice over possible Medicare fraud tied to its Medicare Advantage operations, The Wall Street Journal reported, citing people familiar with the matter. The company's shares were down past 8% premarket.

Biohaven ( BHVN ) stock was more than 11% lower after the company said Wednesday that the US Food and Drug Administration's Office of Neuroscience is extending the Prescription Drug User Fee Act, or PDUFA, date for troriluzole's new drug application for the treatment of spinocerebellar ataxia by three months.

Mesoblast (MESO) shares were up over 7% after the company said overnight it received seven years of orphan drug exclusivity from the US Food and Drug Administration for Ryoncil, a treatment approved for steroid-refractory acute graft versus host disease in children aged two months and older.