Healthcare stocks were lower late Monday afternoon, with the NYSE Healthcare Index shedding 0.4% and the State Street Health Care Select Sector SPDR ETF (XLV) decreasing 0.1%.
The iShares Biotechnology ETF (IBB) fell 0.9%.
In corporate news, Johnson & Johnson (JNJ) eased 0.3% after the firm said it has agreed to buy cancer drug developer Firefly Bio for $1 billion in cash to strengthen its oncology portfolio.
Incyte (INCY) agreed to acquire Vega Therapeutics, a subsidiary of Star Therapeutics, in a deal worth up to $2 billion, expanding its hematology portfolio into bleeding disorders. Shares fell 1%.
Eli Lilly (LLY) shares rose 1.6% after the drugmaker said its experimental obesity drug retatrutide delivered significant weight loss in two clinical studies and also showed "meaningful" improvements in knee osteoarthritis pain and sleep apnea.
Tango Therapeutics (TNGX) surged 51% after the firm said initial results from its phase 1/2 trial of vopimetostat plus Revolution Medicines' daraxonrasib showed a six-month progression-free survival rate of 90% in people with pancreatic cancer.