The reason for the halt is the fact that matters, and it is almost always omitted when this compound is sold. A randomized, double-blind, placebo-controlled trial in ambulatory boys with Duchenne muscular dystrophy, published by Campbell and colleagues in Muscle and Nerve in 2017, was stopped after the second dosing regimen because of safety concerns involving epistaxis, meaning nosebleeds, and telangiectasias, meaning dilated blood vessels visible at the skin surface. The effects are attributed to off-target inhibition of BMP9 and BMP10 signaling, producing something mechanistically resembling hereditary hemorrhagic telangiectasia. So the record is this: ACE-031 was given to human beings under trial conditions, it produced vascular adverse events serious enough to stop the study, and its developers abandoned it. It continues to be sold.