Palomar Labs spun out Ariadne Bio to develop AB-300, a non-hallucinogenic 5-HT2A receptor agonist targeting apathy in Parkinson’s disease. The venture studio said Ariadne will focus on proof-of-concept in a neuropsychiatric area with limited approved therapies aimed specifically at restoring motivation. Ariadne Bio is led by Palomar managing partner Shlomi Raz as CEO, with Daniel Jeffries, PhD as chief development officer. The program targets apathy, a prevalent and disabling non-motor symptom in Parkinson’s, and the company argues the approach is distinct from treating depression. Palomar’s stated spinout strategy centers on candidates with some history of human use, aiming to reduce early clinical risk by moving toward clinic with prior evidence on safety and biological activity. The company’s choice of a 5-HT2A agonist reflects an attempt to modulate neuropsychiatric circuitry while avoiding hallucinogenic side effects. For Parkinson-focused investors and developers, Ariadne’s launch adds to a growing neuropsychiatric pipeline theme that seeks symptom-specific differentiation beyond dopamine replacement.