Aardvark Therapeutics voluntarily paused dosing and enrollment in its Phase 3 HERO trial of ARD‑101 for Prader‑Willi syndrome after routine safety monitoring in a healthy‑volunteer study revealed reversible cardiac observations at supra-therapeutic doses. The company said it will comprehensively review the data to define next steps and optimal therapeutic dosing. The pause prompted a sharp market reaction, with Aardvark’s shares losing roughly half their value as investors repriced program and timeline risk. ARD‑101 is a gut‑restricted TAS2R pan‑agonist aimed at stimulating enteroendocrine satiety hormones; investigators and the company noted the cardiac signals were observed at doses above the intended therapeutic range, but the event forced enrollment suspension and delayed prospective readouts.