Palomar Labs spun out Ariadne Bio to develop AB-300, a clinical-stage, non-hallucinogenic 5-HT2A receptor agonist targeting apathy in Parkinson’s disease. Palomar positioned the spinout around candidates with prior human validation, with Shlomi Raz taking the CEO role and Daniel Jeffries as chief development officer. Ariadne Bio plans to move AB-300 through proof-of-concept and clinical development aimed at a symptom category that Palomar says has no approved therapies designed to restore motivation. The company framed apathy as a high-burden non-motor feature and noted its distinction from Parkinson’s-associated depression. The formation reflects continued investor interest in neuropsychiatric symptom innovation, especially where mechanistic targets have plausible human relevance and differentiation around tolerability.