Palomar Labs (formerly Negev Labs), a venture studio that builds companies around neuropsychiatric drug development programmes with prior human validation, has announced the spinout of Ariadne Bio, its first portfolio company.  

Ariadne Bio launches with lead programme AB-300, a clinical-stage-ready, non-hallucinogenic serotonin 2A receptor agonist in development for apathy in Parkinson’s disease.  

The Michael J Fox Foundation for Parkinson’s Research (MJFF) has awarded Ariadne Bio funding to support a Phase Ib trial of AB-300, expected to begin in the second half of 2026. 

The funding was awarded through The Michael J Fox Foundation’s Parkinson’s Disease Therapeutics Pipeline Program. 

Apathy, defined clinically as a persistent reduction in goal-directed behaviour, affects approximately 40% of people with Parkinson’s disease over the course of the illness, with higher rates reported in mid-to-late stages. 

No therapy is approved specifically for apathy in any indication. Selective serotonin reuptake inhibitors (SSRIs) remain appropriate treatment for depression in Parkinson’s disease, but a growing body of evidence associates them with emotional blunting and worsening apathy. 

“A significant portion of people with Parkinson’s will lose the drive to do the things that make life worth living, and not a single approved medicine is designed to bring it back,” said Shlomi Raz, Founder and Chief Executive Officer of Ariadne Bio. “We built Ariadne Bio around a single question: whether motivation can be restored pharmacologically. AB-300 is how we intend to answer it.” 

At the American Society of Clinical Psychopharmacology (ASCP) annual meeting in May 2026, Ariadne Bio presented data from a preclinical model of tetrabenazine (TBZ)-induced motivational deficit, assessed by progressive-ratio lever pressing. In this widely used model of effort-based motivated behaviour, AB-300 plus TBZ increased motivational behaviour by 89% relative to the TBZ only group, a statistically significant improvement.