Nerve Damage From Tumors Blocks Immunotherapy — Here's How to Fix It

Checkpoint immunotherapy targeting PD-1 has transformed cancer treatment, yet a large proportion of patients fail to respond or develop resistance. Understanding the mechanisms behind this resistance is one of oncology's most pressing challenges. This landmark 2025 Nature study identifies cancer-induced peripheral nerve injury as a novel, clinically relevant driver of anti-PD-1 resistance.

The research team, spanning MD Anderson Cancer Center, Karolinska Institutet, Queen's University, and multiple other institutions, focused primarily on head and neck squamous cell carcinoma (HNSCC) and melanoma — cancers known for perineural invasion. They demonstrated that tumors physically damage surrounding peripheral nerves, activating a stereotyped nerve-injury response. This response involves the upregulation of nerve repair programs (including Schwann cell dedifferentiation and axon regeneration pathways) that paradoxically create a profoundly immunosuppressive tumor microenvironment (TME).

Mechanistically, injured nerves were found to secrete signals — including neuropeptides and damage-associated molecular patterns — that polarize tumor-associated macrophages toward an immunosuppressive phenotype and physically exclude CD8+ cytotoxic T lymphocytes from the tumor core. Single-cell RNA sequencing of human tumors confirmed that high nerve-injury gene signatures correlated with T cell exclusion, macrophage immunosuppression, and poor clinical responses to anti-PD-1 therapy across multiple patient cohorts. Spatial transcriptomics further mapped the neuro-immune crosstalk within the TME, showing that nerve-injury signals create localized immunosuppressive niches.

Critically, the team demonstrated that intervening in this nerve-injury axis could restore immunotherapy sensitivity. In mouse models, pharmacological blockade of nerve-injury signaling — or genetic approaches to promote nerve regeneration rather than a repair-associated immunosuppressive state — significantly improved anti-PD-1 efficacy and tumor control. These interventions shifted macrophage polarization toward pro-inflammatory phenotypes and enabled robust T cell infiltration. The combination of nerve-targeting strategies with anti-PD-1 produced synergistic anti-tumor responses that neither approach achieved alone.

The clinical implications are substantial. Perineural invasion is a common pathological feature in HNSCC, melanoma, and other solid tumors, and patients with this feature typically have worse prognoses and poorer immunotherapy responses. This study provides a mechanistic explanation for that clinical observation and, importantly, identifies actionable therapeutic targets. The neuro-immune axis — specifically the signals released by cancer-injured nerves — represents a new class of immunotherapy resistance mechanism that could be targeted with existing or novel agents to expand the population of patients who benefit from checkpoint blockade.