Non-invasive electromagnetic fields induce anti-tumor neutrophil reprogramming and enhance checkpoint blockade in breast cancer

Introduction Neutrophil reprogramming toward interferon-activated anti-tumor states represents an emerging mechanism of checkpoint sensitization; however, effective strategies to selectively induce this response in the tumor microenvironment remain elusive. Methods We evaluated Asha Therapy, an investigational non-invasive, low-intensity (50 kHz, 2 mT) alternating magnetic field, in triple-negative breast cancer (TNBC) cells, integrating temporal transcriptomics, global proteomics, and cytokine profiling. CITE-seq profiling of tumor tissue was used to characterize the response of neutrophils and other cell populations in the tumor microenvironment. Therapeutic efficacy of Asha Therapy alone and in combination with anti-PD1 blockade was assessed in a murine TNBC model. A 19-gene neutrophil activation signature was derived from Asha-treated tumors and projected onto three independent human TNBC cohorts (METABRIC, n=348; SCAN-B, n=874; TCGA-BRCA, n=191), with multivariable Cox models adjusted for age, tumor stage, nodal status, and TNBC subtype. Results Asha Therapy elicited a controlled endoplasmic reticulum (ER) stress response and adaptive unfolded-protein response in TNBC cells. This tumor-intrinsic stress matured from an acute signaling state into an immune-recruiting secretory program characterized by release of CXCL10, CCL2, and CCL20. These signals were associated with selective expansion and activation of neutrophils toward an interferon-responsive state, with additional transcriptional signatures observed within macrophage, T cell, and cancer-associated fibroblast populations. In the murine TNBC model, Asha monotherapy showed directional anti-metastatic effects, while combination with anti-PD1 blockade achieved significant therapeutic benefit, reducing lung metastasis and mortality by 88% (HR=0.12, p<0.05) without overt cytotoxicity. Projection of the 19-gene neutrophil activation signature onto the three human TNBC cohorts revealed significant association with improved overall survival (pooled HR=0.71, 95% CI: 0.60–0.83, p=0.01). Discussion These findings indicate neutrophil reprogramming as a key feature of the low-intensity EMF therapeutic response. These preclinical findings support further investigation of Asha Therapy as a candidate non-pharmacologic strategy to activate innate immunity and improve responsiveness to checkpoint blockade in poorly immunogenic tumors.