Health care stocks declined Monday afternoon, with the NYSE Health Care Index down 1% and the Health Care Select Sector SPDR Fund (XLV) falling 1%.

The iShares Biotechnology ETF (IBB) decreased 0.6%.

In corporate news, STAAR Surgical (STAA) shares fell 4% after the company said Monday the go-shop period under its merger agreement with Alcon (ALC) has expired with no competing proposals received. Alcon was down 1.9%.

PROCEPT BioRobotics (PRCT) still has a large market opportunity for its aquablation technology to treat benign prostatic hyperplasia, but utilization growth has slowed, BofA Securities said in a research report. The brokerage downgraded the stock to neutral from buy and lowered its price target to $38 per share from $55. PROCEPT shares dropped 4.8%.

Wave Life Sciences (WVE) shares soared 129% after the company said interim data from its phase 1 trial of WVE-007 to treat obesity showed improvements in body composition, with weight loss similar to GLP-1, but without muscle loss, at three months compared to baseline at its lowest therapeutic dose.

Structure Therapeutics (GPCR) shares surged 86% after it said Monday its obesity drug candidate aleniglipron achieved statistical significance in the phase 2b trial's primary and key secondary endpoints.