Health care stocks were steady pre-bell Wednesday, with the Health Care Select Sector SPDR Fund (XLV) a slight 0.1% higher and the iShares Biotechnology ETF (IBB) inactive.

Acadia Pharmaceuticals (ACAD) stock was down more than 11% after the company said its ACP-101, or intranasal carbetocin, therapy candidate for patients with hyperphagia in Prader-Willi syndrome did not meet its primary efficacy endpoint in a phase 3 trial.

Soleno Therapeutics (SLNO) shares were up more than 13% after a rival therapy from Acadia Pharmaceuticals failed to meet its primary endpoint in a phase 3 trial.

UniQure (QURE) stock was up more than 153% after the company said its phase 1/2 study in Huntington's disease met its primary endpoint, with high-dose AMT-130 showing statistically significant 75% slowing of disease at 36 months as measured by the composite Unified Huntington's Disease Rating Scale.