DDDR-74. Pharmacoscopy-guided discovery of vortioxetine as a repurposable neuroactive therapeutic for glioblastoma

Abstract Glioblastoma is an aggressive primary brain tumor with few effective treatment options beyond DNA-alkylating agents like temozolomide. In search of novel therapeutic strategies, we leveraged pharmacoscopy - a high-throughput, single-cell-resolved ex vivo imaging platform - to systematically evaluate the therapeutic potential of repurposable neuroactive drugs (NADs) directly in patient-derived tissues. Utilizing freshly resected tumor samples from glioblastoma patients, we screened 132 clinically approved drugs ex vivo and over 1 million compounds in silico. Vortioxetine, an antidepressant with established CNS bioavailability, demonstrated the most potent and consistent tumor-selective toxicity among NADs, with significant responses observed in 31 of 41 patient samples (75.6%). Molecular machine learning of drug–target networks revealed that NADs with anti-glioblastoma activity converged on a shared transcriptional program defined by the AP-1/BTG regulatory axis known to mediate neural signaling and tumor suppression. Deep multi-omic profiling confirmed that vortioxetine strongly activates this pathway, and patient-specific ex vivo responses to vortioxetine were significantly correlated with the induction of individual AP-1 transcription factors. While this mechanism was observed across other active neuroactive drugs, vortioxetine elicited the most robust and consistent AP-1/BTG-driven response. In orthotopic glioblastoma mouse models, vortioxetine showed consistent survival benefit across five independent preclinical trials, while combination therapy of vortioxetine with temozolomide or lomustine led to a 25–30% extension in overall survival compared to either agent alone. Here we used pharmacoscopy to rapidly and scalably profile patient tumors at single-cell resolution, demonstrating its clinical utility for personalized neuro-oncology. The functional relevance of this imaging-based precision medicine platform was confirmed by its concordance with temozolomide sensitivity and established prognostic markers such as MGMT status. Bridging neuroscience and oncology, our research advances a framework for targeting glioblastoma based on its neural etiology and identifies vortioxetine as promising repurposable therapeutic.