Abstract B085: Modulating the tumor microenvironment in with alternating magnetic fields: preclinical findings on Asha Therapy

Abstract Immunotherapy often relies on biologics with systemic administration, which can lead to adverse side effects. An innovative approach utilizes a wearable device to deliver alternating magnetic fields (AMFs) to induce localized immune responses in tumors. Here, we present results from preclinical evaluation of Asha™ Therapy, a proprietary, low-intensity (1–3 mT), 50 kHz AMF application, developed to locally induce cancer immunity. To explore the potential for Asha therapy as a treatment for solid tumors, an orthotopic murine model of triple negative breast cancer (TNBC), the 4T1 model, was employed. In vivo, a syngeneic 4T1 TNBC model tumor bearing was established by inoculating 4T1 cells into the mammary pads of the female BALB/c mice. Following confirmation of tumor development, mice were randomized into treatment and control groups. Mice in the treatment group received Asha therapy, and after one week of exposure, tumors were excised for single-cell RNA sequencing (scRNA-seq). Data analysis revealed that, compared to controls, the treatment group showed a significant increase in M1 macrophages and neutrophils, a decrease in M2 macrophages and regulatory T cells (Tregs), and a significantly higher inflammation score based on the Hallmark inflammation gene set (p<0.001). Subsequently, in a 4-week study using the same 4T1 model, Asha therapy decreased lung metastasis, by >2 folds when compared to untreated controls. When combined with the immune checkpoint inhibitor anti-PD1, lung metastasis was further reduced, showing a 14-fold decrease compared to controls. Flow cytometry analysis of the resected primary tumor at the study end (4 weeks), showed that Asha therapy exposure resulted in significant reduction of myeloid-derived suppressor cells (MDSCs)(p<0.01), and increased CD8+ T cell numbers, indicating a strong immune-mediated antitumor response. To understand whether Asha therapy can directly act on the immune cells within the tumor, in vitro studies were performed using C57BL/6 bone marrow-derived macrophages (BMDM). After polarizing BMDMs to M2 type, they were treated with Asha Therapy for 48 hours. Controls included untreated cells, and a positive control treated with lipopolysaccharide (LPS) and interferon-gamma (IFNγ). Asha-treated cells showed a significant reduction in Arg1 expression (qPCR, p<0.001), and significantly decreased F4/80+CD206+ surface biomarkers (flow cytometry, p<0.005), with findings replicated in three independent experiments. Cytokine measurement in the culture supernatants showed increased pro-inflammatory (CXCL10, CCL4, CCL3) and decreased anti-inflammatory (IL-9, IL-15, VEGF) cytokines in the treatment group, compared to the control group. Similar experiments using human PBMC-derived M2 macrophages showed comparable results: a 48-hour treatment with Asha significantly decreased CD163+CD206+ surface markers (flow cytometry, p<0.01). These preclinical findings suggest that Asha Therapy has promising potential as an immunotherapy for solid tumors, warranting further investigation. Citation Format: Vivek Sharma, Sandra Santulli-Marotto, Kishori Konwar. Modulating the tumor microenvironment in with alternating magnetic fields: preclinical findings on Asha Therapy [abstract]. In: Proceedings of the AACR IO Conference: Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2025 Feb 23-26; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2025;13(2 Suppl):Abstract nr B085.