Health care stocks fell late Friday afternoon, with the NYSE Health Care Index down 0.3% and the Health Care Select Sector SPDR Fund (XLV) easing 0.2%.

The iShares Biotechnology ETF (IBB) rose 0.9%.

In corporate news, Sarepta Therapeutics' (SRPT) Elevidys gene therapy will now carry a boxed warning and a restricted indication following reports of fatal acute liver failure in non-ambulatory Duchenne muscular dystrophy patients, the US Food and Drug Administration said Friday. Sarepta shares were up nearly 7%.

Merck (MRK) agreed to buy immunotherapy developer Cidara Therapeutics (CDTX) for $9.2 billion to expand its respiratory portfolio. Merck shares added 0.1%, and Cidara surged 105%.

Bristol-Myers Squibb (BMY) shares fell 3.9% after the company and Johnson & Johnson (JNJ) stopped a Phase 3 trial of their experimental drug milvexian for people recovering from a recent acute coronary syndrome event. Johnson & Johnson shares rose 0.4%.

Novo Nordisk (NVO) elected Lars Rebien Sorensen as board chair at its extraordinary general meeting. Sorensen succeeds Helge Lund, who stepped down from the board along with several other members. Novo shares fell 2%.