Researchers from Vanderbilt University Medical Center and Stanford University introduced a single-cell spatial pharmacology (SSP) platform to visualize where antibody drugs distribute and engage targets inside human solid tumors. In work published in Nature Biotechnology, the team used the approach to analyze drug delivery and target engagement across multiple solid tumor types. Their findings pointed to stromal architecture as a consistent limiting factor for antibody penetration and downstream engagement. The study included analysis of panitumumab-IRDye800CW used in investigational settings, aiming to distinguish whether failures stem from delivery limitations versus insufficient activity after entry. The results provide a practical translational framework for next-generation antibody engineering and trial selection by directly measuring the barriers in patient-like tumor tissues.