09:16 AM EST, 11/24/2025 (MT Newswires) -- Health care stocks were advancing premarket Monday, with the Health Care Select Sector SPDR Fund ( XLV ) up 0.4% and the iShares Biotechnology ETF (IBB) 0.8% higher.

Novo Nordisk ( NVO ) stock was down more than 10% after the company said its weight-loss drug semaglutide failed to meet its primary endpoint of reducing Alzheimer's progression in two phase 3 trials enrolling a total of 3,808 adults.

Merck ( MRK ) said late Friday that shareholders should not participate in the unsolicited mini-tender offer launched by Tutanota at $65 per share, which is well below recent market prices. Merck ( MRK ) stock was up nearly 3% premarket.

Biogen (BIIB) shares were nearly 2% higher after the company and Dayra Therapeutics said they have entered a collaboration to research and develop oral macrocyclic peptides for priority targets in immunological conditions.