NEURO-EMPATHIC BRIDGE A Preclinical Model for Predicting Subjective Intolerability Prior to Clinical Trials

Background: Many pharmacological compounds fail in early-phase clinical trials not due to toxicity or inefficacy, but because of subjective intolerability — adverse sensations reported by patients such as mental fog, discomfort, detachment, or anxiety, despite no observable pathology. Subjective effects—such as affective flattening or depersonalization — have become major contributors to CNS compound rejection in Phase I studies [1,2,3]. Objective: We propose a novel preclinical model — the Neuro-Empathic Bridge — designed to detect early affective and functional disruption in animal models that parallels human subjective experience. Methods: Using a combination of behavioral analysis, neurophysiological monitoring (MEA/EEG), autonomic indicators, and affective hormone profiling, we developed a composite metric — the Unacceptability Risk Index (URI) — to quantify subclinical dysregulation. The model was applied across several known CNS-active compounds with divergent tolerability profiles in humans. Results: Compounds that caused subjective rejection in Phase I, but passed classical toxicity screens, consistently produced elevated URI scores (≥6). These scores corresponded with measurable affective pattern disruptions including reduced γ-band coherence, dopaminergic flattening, behavioral anhedonia, and gut-vagal dysregulation. Conclusion: The Neuro-Empathic Bridge provides a translational framework to bridge preclinical and subjective human experience, enabling early identification of “subtle rejection risk” in candidate molecules — potentially reducing late-stage trial failure and improving human-centered drug design.