Health care stocks were advancing premarket Friday as the Health Care Select Sector SPDR Fund (XLV) was up 0.5% and the iShares Biotechnology ETF (IBB) was 0.6% higher recently.

Novo Nordisk's (NVO) obesity and diabetes drug semaglutide has a "very rare side effect" whereby patients taking the drug could develop a condition that may cause loss of vision, the European Medicines Agency said. Novo Nordisk shares were more than 2% higher pre-bell.

Arvinas (ARVN) and Pfizer (PFE) submitted a new drug application to the US Food and Drug Administration for vepdegestrant as a treatment for patients with ESR1-mutated advanced or metastatic breast cancer. Arvinas shares were up more than 1% premarket.

BioCryst Pharmaceuticals (BCRX) shares were 0.7% higher after the company said its Orladeyo drug has been approved for reimbursement in the Netherlands for the routine prevention of hereditary angioedema attacks in patients aged 12 years and up.