09:18 AM EDT, 05/18/2026 (MT Newswires) -- Healthcare stocks were declining pre-bell Monday, with the State Street Health Care Select Sector SPDR ETF (XLV) down 0.5% and the iShares Biotechnology ETF (IBB) 0.6% lower.

Regeneron Pharmaceuticals (REGN) stock was down more than 11% after the company said two dose levels of fianlimab in combination with cemiplimab, evaluated as a first-line treatment in unresectable locally advanced or metastatic melanoma, failed to meet a primary endpoint in its phase 3 trial.

Bio-Rad Laboratories (BIO) has attracted a sizable investment from Elliott Investment Management, which plans to push the life-science tools supplier to improve its lagging stock performance, The Wall Street Journal reported, citing people familiar with the matter. Bio-Rad Laboratories shares were up more than 7% premarket.

Boston Scientific (BSX) entered into a $2 billion accelerated share repurchase agreement with JPMorgan Chase (JPM) as part of its previously announced $5 billion share buyback authorization, the company said. Boston Scientific also said it invested $1.5 billion for an approximately 34% stake in privately held MiRus. Shares of Boston Scientific were up about 2% pre-bell.