Palomar Labs spun out Ariadne Bio to advance AB-300, a clinical-stage, non-hallucinogenic serotonin 2A receptor agonist designed to treat apathy in Parkinson’s disease. Ariadne Bio’s lead program aims to restore motivation in a symptom area where no approved therapy is specifically targeted, according to the company. Apathy is described as a persistent reduction in goal-directed behavior and is reported as a common non-motor burden for people with Parkinson’s, often distinct from depression. The spinout is also notable for Palomar’s venture-studio strategy of selecting drug candidates with prior human validation and moving them into proof-of-concept clinical development.