Healthcare stocks were leaning lower pre-bell Wednesday, with the State Street Health Care Select Sector SPDR ETF (XLV) down 0.2% and the iShares Biotechnology ETF (IBB) declining by 0.5%.

National Vision Holdings (EYE) stock was down more than 11% after the company reported fiscal Q1 revenue that missed analysts' estimates.

Alto Neuroscience (ANRO) shares were down more than 3% after the company posted a wider Q1 net loss.

Personalis (PSNL) said the Molecular Diagnostic Services Program of the Centers for Medicare & Medicaid Services has expanded coverage for the firm's NeXT Personal minimal residual disease test. Personalis stock was up more than 14% premarket.