Palomar Labs spun out Ariadne Bio to advance AB-300, a clinical-stage, non-hallucinogenic serotonin 2A receptor agonist aimed at Parkinson’s apathy. The venture studio said Ariadne’s focus is specifically motivational impairment, a non-motor symptom affecting a large fraction of people with Parkinson’s disease and lacking dedicated approved therapies. Ariadne’s program is designed to test whether motivational drive can be restored pharmacologically, while distinguishing apathy from Parkinson’s-associated depression where different treatment standards apply. Palomar’s stated approach also emphasizes candidates with prior human-use history to de-risk early clinical steps. The spinout highlights growing attention to late-life neuropsychiatric targets and the effort to address functional impairment that can fall outside classic motor endpoints in Parkinson’s studies.