Researchers at Vanderbilt University Medical Centre and Stanford University School of Medicine have developed a new analytical platform capable of visualising how antibody-based therapies distribute within solid tumours at single-cell resolution, providing a tool to distinguish treatment failures caused by poor drug delivery from those caused by insufficient biological activity. The study is published in Nature Biotechnology.
The platform, termed single-cell spatial pharmacobiology (SSP), maps drug-tumour interactions across the spatial architecture of human solid tumours, allowing researchers to assess where a therapeutic agent reaches within the tumour, which cell types it engages, and how strongly it binds its molecular target. The technology was applied to pancreatic cancers and tumours of the head and neck, two cancer types where antibody-based therapies frequently show limited efficacy.
Findings using SSP revealed pronounced spatial heterogeneity in drug distribution across different tumour regions and tumour types. The research identified the dense stromal architecture surrounding tumour cells, comprising non-cancerous supportive tissue, as a consistent physical barrier to drug penetration. This structural impediment appears to prevent therapeutic antibodies from reaching significant portions of the tumour, irrespective of systemic drug exposure.
The study incorporated data from Phase 1 clinical trials investigating panitumumab-IRDye800CW, an antibody conjugate under evaluation for fluorescence-guided surgery. SSP analysis of these samples allowed the team to differentiate tumour regions that were biologically unresponsive to the agent from those that were simply underexposed due to delivery barriers.
The authors note that current pharmacological imaging tools do not provide sufficient resolution to make this distinction, and suggest that SSP could inform the design of future trials by identifying structural barriers to drug efficacy earlier in the development process.
Source: Rosenthal E et al. Single-cell spatial pharmacobiology identifies conserved stromal barriers to therapeutic antibody delivery in human solid tumours. Nature Biotechnology (2026). DOI: 10.1038/s41587-026-03152-x
